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Lawrence Livermore National Laboratory (LLNL) researchers and their colleagues from Lawrence Berkeley Laboratory and the Nanosystem Research Institute in Japan have identified electrical charge-induced changes in the structure and bonding of graphitic carbon electrodes that may one day affect the way energy is stored. The research could lead to an improvement in the capacity and efficiency of electrical energy storage systems, such as batteries and supercapacitors, needed to meet the burgeoning demands of consumer, industrial and green technologies.
The LLNL-led team developed a new X-ray adsorption spectroscopy capability that is tightly coupled with a modeling effort to provide key information about how the structure and bonding of graphitic carbon supercapacitor electrodes are affected by polarization of the electrode – electrolyte interfaces during charging. A paper describing their work is published in the journal Advanced Materials.
Electrode/electrolyte interfaces are critical to all electrical energy storage technologies, yet there remains limited understanding of how physiochemical properties of these devices are altered by the interfacial electric field generated during charging. The structural and dynamical responses of the electrolyte to an applied potential have been extensively studied, whereas the analogous responses of the electrode material during operation remain largely unexplored, even for widely used materials such as graphitic electrodes. Herein, we demonstrate that graphene-based supercapacitor electrodes undergo complex, electric field induced, changes in electronic structure during operation that have their origin in modifications to the electrode surface chemistry and morphology.
… Our results bolster a nascent model in which inter-facial capacitance and charge storage are not solely determined by the isolated properties of the electrode and electrolyte, but can be strongly influenced by polarization-induced and electrolyte-mediated modifications to the electrode itself. —Bagge-Hansen et al.
The complex and dynamic behavior of polarized electrode–electrolyte interfaces strongly influence the core functionality of all electrochemical energy storage systems—and especially for electric double layer (EDL) capacitors, or supercapacitors. Supercapacitors store electrical energy solely by polarization of the electrode–electrolyte interface. Accordingly, the LLNL team noted, the desire for significantly increased capacity and efficiency of EDL capacitors and other electrochemical energy storage systems has motivated extensive research focused on the electrolyte—i.e., the transport, proximity, and arrangement of ions approaching the electrode surface.
On the other hand, very little is known about the equally important dynamic physiochemical response of the electrode to charge and discharge, including any electric-field induced changes to the electronic structure during operation. Instead, the electrode is conventionally considered to be static, with charge accumulation or depletion as the only response to polarization of the interface. This lack of understanding of the dynamic physio-chemical changes of the electrode is largely due to the paucity of experimental and theoretical methods for characterization of the electrode electronic structure under operating conditions. —Bagge-Hansen et al.
Graphitic supercapacitors are ideal model systems to probe interfacial phenomena because they are chemically relatively stable, extensively characterized experimentally and theoretically and are interesting technologically. The team used its recently developed 3D nanographene (3D-NG) bulk electrode material as a model graphitic material.
3D-NG (graphene aerogel, earlier post) is composed of interconnected single-layer graphene sheets, is binder- and substrate-free, and has a well-characterized hierarchical pore structure.
Our newly developed X-ray adsorption spectroscopy capability allowed us to detect the complex, electric-field induced changes in electronic structure that graphene-based supercapacitor electrodes undergo during operation. Analysis of these changes provided information on how the structure and bonding of the electrodes evolve during charging and discharging. The integration of unique modeling capabilities for studying the charged electrode-electrolyte interface played a crucial role in our interpretation of the experimental data.—Jonathan Lee, corresponding author
Discovering that the electronic structure of graphitic carbon supercapacitor electrodes can be tailored by charge-induced electrode-electrolyte interactions opens a new window toward more efficient electrochemical energy storage systems. In addition, the experimental and modeling techniques developed during the research are readily applicable to other energy storage materials and technologies.
Other Livermore researchers include Michael Bagge-Hansen, Brandon Wood, Tadashi Ogitsu, Trevor Willey, Ich Tran, Arne Wittstock, Monika Biener, Matthew Merrill, Marcus Worsley, Theodore Baumann, Tony van Buuren and Jürgen Biener. The research was conducted in collaboration with scientists at additional institutions, including Minoru Otani from the Nanosystem Research Institute in Japan; David Prendergast from the Molecular Foundry; and Jinghua Guo and Cheng-Hao Chuang of the Advanced Light Source Division at Lawrence Berkeley National Laboratory. A substantial portion of the research was supported by LLNL’s Laboratory Directed Research and Development (LDRD) program.
Bagge-Hansen, M., Wood, B. C., Ogitsu, T., Willey, T. M., Tran, I. C., Wittstock, A., Biener, M. M., Merrill, M. D., Worsley, M. A., Otani, M., Chuang, C.-H., Prendergast, D., Guo, J., Baumann, T. F., van Buuren, T., Biener, J. and Lee, J. R. I. (2015) “Potential-Induced Electronic Structure Changes in Supercapacitor Electrodes Observed by In Operando Soft X-Ray Spectroscopy.” Adv. Mater., 27: 1512–1518. doi: 10.1002/adma.201403680
Over the last few years, Neste Oil has become the world’s largest producer of renewable fuels from waste and residues. In 2014, the company produced nearly 1.3 million tonnes (1.6 billion liters, 423 million gallons US) of renewable fuel from waste and residues. In practical terms, this is enough to power for two years all the 650,000 diesel-powered passenger cars in Finland with NEXBTL renewable diesel manufactured from waste and residues.
Examples of Neste Oil’s waste and residue-based raw materials include animal and fish fats; used cooking oil; and various residues generated during vegetable oil refining such as palm fatty acid distillate (PFAD) and technical corn oil. These raw materials accounted for 62% of Neste Oil’s renewable inputs in 2014 (52% in 2013, 35% in 2012).
NEXBTL products (renewable diesel, jet, and naphtha fuels and isoalkane) are produced by hydrotreating vegetable oil or animal fat (HVO).
We can be really proud that we have succeeded in increasing our use of waste and residue-based feedstocks in the production of renewable NEXBTL fuels to such a significant extent. Thanks to this, Neste Oil has in just a few years become the world’s largest circular economy enterprise in the biofuels sector. The production of fuels from waste-based feedstock is resource-efficient, and our aim is to have the capability to use 100% waste and residues by 2017. We are constantly searching for new waste-based raw materials of increasingly poorer quality, and use the majority of our EUR 40 million [US$44 million] R&D expenditure for raw material research.—Kaisa Hietala, Executive Vice President of Neste Oil’s Renewable Products business area
Additionally, Neste Oil manufactures renewable products from vegetable oils, mainly from crude palm oil. Its proportion of the total feedstock usage has decreased markedly over the past few years and currently stands at 38% (47% in 2013, 65% in 2012).
In all, Neste Oil is already able to produce renewable diesel from more than ten different raw materials, and the total amount of renewal diesel produced by Neste Oil in 2014 would suffice to power 2.8 million passenger cars for one year.
All of the company’s renewable raw materials are sustainably produced and comply with both the requirements set out by legislation and the company’s own stringent sustainability criteria. With regard to crude palm oil, Neste Oil only uses certified feedstock.
Neste Oil produces renewable products based on its proprietary NEXBTL technology in its refineries located in Finland, the Netherlands, and Singapore. With its annual capacity of 2 million tonnes, the company is the world’s largest producer of renewable diesel.
The goal is to increase annual capacity to 2.6 million tonnes without making any major additional investments. Additionally, the NEXBTL product range will expand to cover entirely new applications outside traffic fuels, such as the chemical industry.
Oil and gas operations in the United States produce about 21 billion barrels of wastewater per year, with accompanying disposal costs of about $5 billion per year. The saltiness of the water and the organic contaminants it contains have traditionally made treatment difficult and expensive. Engineers at the University of Colorado Boulder and New Mexico State University have developed a simpler process that can simultaneously remove both salts and organic contaminants from the wastewater, all while producing additional energy.
A description of the technology—microbial capacitive desalination—was recently published in an open access paper in the RSC journal Environmental Science Water Research & Technology as the cover story.
One approach to accomplish sustainable produced water management is to develop technologies that remove both organic contaminants and salts without external energy consumption or potential net energy gain. In this context, recently developed microbial desalination systems (MDS) may provide a niche in the market. MDS is based on the fundamental work on bioelectrochemical systems (BES), which employ microorganisms to breakdown organic or inorganic sources of electrons and transfer those electrons to a terminal electron acceptor such as oxygen through a pair of electrodes. The internal potential generated between the anode and the cathode drives additional salt removal, and the energy can be harvested for electricity and chemical production. Different reactor configurations have been reported, such as a microbial desalination cell (MDC), in which three chambers were separated by a pair of ion exchange membranes and salt removal was accomplished by migrating ions from the middle chamber to the anode and cathode chambers.
This study used a newly developed microbial capacitive desalination cell (MCDC) to demonstrate its efficacy in removing both organic contaminants and salts from produced water collected from a shale gas field and its energy recovery during the operation. MCDC alleviates salt migration problems associated with MDC through the integration with capacitive deionization (CDI). CDI is a desalination method where an electrical potential is applied to high surface area electrodes to adsorb charged organic and inorganic species for desalination. CDI is a dynamic process of salt removal and recovery. When the electrical potential is removed, the capacitively desalinated salts can be removed and captured for beneficial use, and part of the electrical charge can be recovered.
CDI only requires a small voltage (<1.4 V) to form the electric double layer, so it can be externally powered by an MFC [microbial fuel cell]. Previous studies showed that such an MFC–CDI system could achieve a desalination rate of 35.6 mg of TDS per liter per hour, with a desorption rate up to 200.6 mg of TDS per liter per hour.—Forrestal et al.
This microbial electrochemical approach takes advantage of the fact that the contaminants found in the wastewater contain energy-rich hydrocarbons, the same compounds that make up oil and natural gas. The microbes used in the treatment process eat the hydrocarbons and release their embedded energy. The energy is then used to create a positively charged electrode on one side of the cell and a negatively charged electrode on the other.
The MCDC system consists of three chambers, the anode, cathode and middle chambers which contain the electrodes for CDI.
The microbial capacitive desalination cell was able to remove total dissolved solids (TDS) at a rate of 2760 mg of TDS per liter per hour and chemical oxygen demand (COD) at a combined rate of 170 mg of COD per liter per hour—18 times and 5 times faster than the traditional microbial desalination cell (MDC), respectively. The MCDC had a coulombic efficiency of 21.3%, and during capacitive deionization regeneration, 1789 mJ g−1 activated carbon cloth (ACC) was harvested.
Market background. Some oil and gas wastewater is currently being treated and reused in the field, but that treatment process typically requires multiple steps—sometimes up to a dozen—and an input of energy that may come from diesel generators.
Because of the difficulty and expense, wastewater is often disposed of by injecting it deep underground. The need to dispose of wastewater has increased in recent years as the practice of hydraulic fracturing, or “fracking,” has boomed. Fracking refers to the process of injecting a slurry of water, sand and chemicals into wells to increase the amount of oil and natural gas produced by the well.
Injection wells that handle wastewater from fracking operations can cause earthquakes in the region, according to past research by CU-Boulder scientists and others.
The demand for water for fracking operations also has caused concern among people worried about scarce water resources, especially in arid regions of the country. Finding water to buy for fracking operations in the West, for example, has become increasingly challenging and expensive for oil and gas companies.
Ren and Forrestal’s microbial capacitive desalination cell offers the possibility that water could be more economically treated on site and reused for fracking.
The beauty of the technology is that it tackles two different problems in one single system. The problems become mutually beneficial in our system—they complement each other—and the process produces energy rather than just consumes it.—Zhiyong Jason Ren, senior author
To try to turn the technology into a commercial reality, Ren and Forrestal have co-founded a startup company called BioElectric Inc. In order to determine if the technology offers a viable solution for oil and gas companies, the pair first has to show they can scale up the work they’ve been doing in the lab to a size that would be useful in the field.
The cost to scale up the technology also needs to be competitive with what oil and gas companies are paying now to buy water to use for fracking, Forrestal said. There also is some movement in state legislatures to require oil and gas companies to reuse wastewater, which could make BioElectric’s product more appealing even at a higher price, the researchers said.
Ren and Forrestal have received funds from the National Science Foundation to work on scaling up the water treatment cell. The grant came after the pair participated in NSF’s Innovation Corps Program—aimed at pushing NSF-funded research beyond the lab—and took first place in their class.
Ren and Forrestal also worked with researchers Zachary Stoll and Pei Xu at New Mexico State University. Stoll and Xu are also co-authors of the article.
Casey Forrestal, Zachary Stoll, Pei Xu and Zhiyong Jason Ren (2015) “Microbial capacitive desalination for integrated organic matter and salt removal and energy production from unconventional natural gas produced water” Environ. Sci.: Water Res. Technol. 1, 47-55 doi: 10.1039/C4EW00050A
Mobileye N.V., a designer and developer of camera-based Advanced Driver Assistance Systems (ADAS) for the automotive industry, introduced its 4th-generation system-on-chip, the EyeQ4. Leveraging the company’s more than 15 years of expertise in designing computer-vision specific cores, the EyeQ4 consists of 14 computing cores out of which 10 are specialized vector accelerators with extremely high utilization for visual processing and understanding.
The first design win for EyeQ4 in series production has been secured for a global premium European car manufacturer for production to start in early 2018. The EyeQ4 would be part of a scalable camera system starting from monocular processing for collision avoidance applications, in compliance with EU NCAP, US NHSTA and other regulatory requirements, up to trifocal camera configuration supporting high-end customer functions including semi-autonomous driving. The EyeQ4 would support fusion with radars and scanning-beam lasers in the high-end customer functions.
Supporting a camera centric approach for autonomous driving is essential as the camera provides the richest source of information at the lowest cost package. To reach affordable high-end functionality for autonomous driving requires a computing infrastructure capable of processing many cameras simultaneously while extracting from each camera high-level meaning such as location of multiple types of objects, lanes and drivable path information. The EyeQ4 continues a legacy that began in 2004 with EyeQ1 where we leveraged deep understanding of computer vision processing to come up with highly optimized architectures to support extremely intensive computations at automotive compliant power consumption of 2-3 Watts.—Prof. Amnon Shashua, co-founder, CTO and Chairman of Mobileye
The EyeQ4 will feature four CPU cores with four hardware threads each, coupled with six cores of Mobileye’s innovative and well-proven Vector Microcode Processors (VMP) that has been running in the EyeQ2 and EyeQ3 generations. The EyeQ4 will also introduce novel accelerator types: two Multithreaded Processing Cluster (MPC) cores and two Programmable Macro Array (PMA) cores.
MPC is more versatile than a GPU or any other OpenCL accelerator, and with higher efficiency than any CPU, according to Mobileye. PMA features compute density nearing that of fixed-function hardware accelerators, and unachievable in the classic DSP architecture, without sacrificing programmability. All cores are fully programmable and support different types of algorithms.
Using the right core for the right task saves both computational time and energy. This is critical, Mobileye says, as the EyeQ4 is required to provide “super-computer” capabilities of more than 2.5 teraflops within a low-power (approximately 3W) automotive grade system-on-chip.
The enhanced computational capabilities give EyeQ4-based ADAS the ability to use advanced computer vision algorithms like Deep Layered Networks and Graphical Models while processing information from 8 cameras simultaneously at 36 frames per second.
The design was done according to the ISO-26262 standard and will provide a safety level of ASIL-B(D). The EyeQ4 will accept multiple camera inputs from a trifocal front-sensing camera configuration, surround-view-systems of four wide field of view cameras, a long range rear-facing camera and information from multiple radars and scanning beam lasers scanners. Taken together, the EyeQ4 will be processing a safety cocoon around the vehicle—essential for autonomous driving.
In addition to the EyeQ4 high capability version, at an ASP of approximately three times that of an ADAS functionality chip, Mobileye also plans the launch of the EyeQ4 “medium” variant within the same timeframe. The EyeQ4M will include a subset of EyeQ4’s computational cores, enabling a select group of functions. In producing a family of EyeQ4 processors Mobileye will ensure that car makers can deliver a scalable hardware solution with full code and pin compatibility, thereby reducing complete validation costs and ensuring that multiple feature bundles can be offered to the end customer at the best possible price.
Engineering samples of EyeQ4 are expected to be available by the fourth quarter of 2015. First test hardware with the full suite of applications including active safety suite of customer functions, environmental modeling (for each of the 8 cameras), path planning for hands-free driving and fusion with sensors, is expected to be available in the second quarter of 2016. Series production is supported for early 2018 start of production.
Mobileye’s EyeQ chip and algorithms have been integrated into new car models since 2007. The first million-chip celebration took place in the middle of 2012. Another 1.3 million chips were added in 2013, and as of March 2014, the chip was estimated to be integrated in approximately 3.3 million vehicles. Mobileye products are or will be integrated into car models from 23 global automakers including BMW, Ford, General Motors, Nissan and Volvo. The products are also available in the aftermarket.
The US Department of Energy (DOE) issued a $12.5 million Funding Opportunity Announcement (FOA) (DE-FOA-0001285) for a new technical track under the US-China Clean Energy Research Center (CERC) that addresses water-related aspects of energy production and use.
The solicitation calls for the formation of a US-based consortium to work with Chinese counterparts to bolster collaborative efforts to help ensure energy, water, and environmental security and combat climate change. The consortium will be funded with $12.5 million DOE support and $12.5 million recipient cost share for a total of $25 million over the 5-year period of performance.
This US investment will be matched by an equivalent effort in China, bringing the total bilateral investment to $50 million.
The new energy-water track was initially announced in November 2014, when President Barack Obama and Chinese President Xi Jinping renewed their commitment to CERC with $200 million in total funding over five years. In addition to expanding work under CERC by $50 million for research in energy and water, the announcement in November extends ongoing collaborative efforts to 2020, adding $150 million to continue initiatives already underway. These focus on the development and deployment of clean vehicles, building energy efficiency, and advanced coal technologies for carbon capture, utilization and sequestration.
This FOA also seeks to transform how water is used in energy production and electricity generation, while improving water quality and availability for a diverse range of human applications. It builds on the contents of The Water-Energy Nexus: Challenge and Opportunities, which DOE issued in June 2014.
Topics covered in the FOA include: water use reduction at thermoelectric plants; treatment & management of non-traditional waters; improving sustainable hydropower design and operation; climate impact modeling, methods, and scenarios to support improved understanding of energy and water systems; and data and analysis to inform planning, policy, and other decisions.
Initially launched in November 2009 by President Barack Obama and former Chinese President Hu Jintao, CERC accelerates development and deployment of clean energy technologies for the benefit of both countries. CERC’s mission is to facilitate technical collaboration in mutually agreed areas and accelerate transition to an efficient and low‐carbon economy, while mitigating the long‐term threat of climate change.
Researchers with the Energy Biosciences Institute (EBI), a partnership that includes Berkeley Lab and the University of California (UC) Berkeley, have introduced new metabolic pathways from the fungus Neurospora crassa into the yeast Saccharomyces cerevisiae to increase the fermentative production of fuels and other chemicals from biomass. An open access paper on the work is publised in the journal eLife.
While S. cerevisiae is the industry mainstay for fermenting sugar from cornstarch and sugarcane into ethanol, it requires substantial engineering to ferment sugars derived from plant cell walls such as cellobiose and xylose. The new metabolic pathways enable the yeast to ferment sugars from both cellulose (glucose) and hemicellulose (xylose)—the two major families of sugar found in the plant cell wall—efficiently, without the need of environmentally harsh pre-treatments or expensive enzyme cocktails.
Jamie Cate, a staff scientist in Berkeley Lab’s Physical Biosciences Division and a professor of biochemistry, biophysics and structural biology at UC Berkeley, and a team of collaborators identified the metabolic pathways in the fungus Neurospora crassa that are used to digest xylose, one of the most abundant sugars in hemicellulose.
In contrast to S. cerevisiae, many cellulolytic fungi including N. crassa naturally grow well on both the cellulose and hemicellulose components of the plant cell wall. By using functional genomics data and N. crassa knockout strains, we identified separate pathways used by N. crassa to consume the cellodextrins and xylodextrins released from plant cell walls by its secreted enzymes.—Jamie Cate, corresponding author
To enable the N. crassa metabolic pathways to work in yeast, Cate and his collaborators introduced five new genes into the yeast. While the new pathways and genes allow the yeast to directly ferment xylose sugars into a desired biofuel or chemical product, those sugars still have to be released from the plant cell walls.
This can be done, however, with a simple hot water-pretreatment rather than the acids or ionic liquids that current pre-treatment methods deploy. Harsh chemicals like acids and ionic liquids, unlike hot water, must be removed prior to fermentation so as not to harm the microbes. This is another major expense in addition to the expensive enzymes required to break down the xylose sugars.
We’ve discovered new chemicals generated by fungi and bacteria as metabolites in their strategy for consuming the plant cell wall that are a general part of the global carbon cycle. We should now be able engineer biofuel-producing yeast to do what these fungi and bacteria do, opening up many new possible scenarios for making biofuels and other important products. We believe that introducing N. crassa metabolic pathways into yeast could find widespread use in helping to overcome existing bottlenecks to the fermentation of lignocellulosic feedstocks as a sustainable and economical source of biofuels and renewable chemicals.—Jamie Cate
This research was funded by EBI.
Xin Li, Vivian Yaci Yu, Yuping Lin, Kulika Chomvong, Raíssa Estrela, Annsea Park, Julie M Liang, Elizabeth A Znameroski, Joanna Feehan, Soo Rin Kim, Yong-Su Jin, N Louise Glass, Jamie HD Cate (2015) “Expanding xylose metabolism in yeast for plant cell wall conversion to biofuels” eLife doi: 10.7554/eLife.05896
by Martin Tillier of Oilprice.com
Oil’s rapid decline since August of last year has been dramatic. To listen to some commentators you would also think it is unprecedented and irreversible. Those claiming that oil will continue to fall from here and remain low for evermore, however, are flying in the face of both history and common sense. The question we should be asking ourselves is not if oil prices will recover, but when they will.
From June of 2014 until now, the price of a barrel of West Texas Intermediate (WTI) crude oil has fallen approximately 57 percent. As the chart below shows, there have been drops of a similar percentage five times in the last 30 years. The rate of recovery has been different each time, but recovery has come. In addition, since 1999 the chart shows a consistent pattern of higher lows. In other words, oil is a volatile market, but prices are in a long term upward trend.
Charts can only tell us so much, however. Even a long term trend can be broken if fundamental conditions change, and that, say those predicting that oil will never recover, is what has happened. There is no doubt that supply has increased. Hydraulic fracturing, or “fracking” technology has unlocked reserves of oil and natural gas previously thought of as unrecoverable. Supply alone, however, doesn’t determine price. We must also consider demand, and that has been increasing too.
According to this chart (above) from the US Energy Information Agency (EIA), demand has been increasing along with supply since 2010. Admittedly there has been a production surplus since the beginning of 2014 but that is nothing new and is forecast to be back in balance by the end of this year. The increased production, then, is in response to increasing demand; hardly a recipe for a protracted period of low prices. The supply situation makes it unlikely that the recovery will be rapid, but a gradual move up over the next few years is the only logical conclusion.
The low price brigade cites another factor in making their predictions, the rise of alternative energy sources. There is no doubt that there have been significant advances in that area, particularly in wind and solar power, but, according to the EIA, renewables currently account for 11 percent of the world’s energy consumption. That number will undoubtedly grow in the coming years, but, whether we like it or not, oil consumption still looks set to grow over the next few years. Fracking can fill some of that demand, but the simple fact remains that oil is still used extensively, and we are using more of it every year. The price simply cannot stay low for an extended period, but while it does it will delay research and infrastructure spending on renewables, slowing the pace of their adoption.
Any increase in price would be hastened by a decision from OPEC and Saudi Arabia in particular, to reduce production. Right now they say that that is not on the cards, and why would they cut back? Their attitude seems to be that the oversupply was not their doing, and as their oil is cheap to produce, they can sit back and watch those who did cause the problem, most notably the upstart American companies, suffer. OPEC has always played the long game and will undoubtedly do so again, but once the lesson has been taught the pressure to restrict supply somewhat will mount. Again it may take time, but it will probably come.
History tells us that the price of oil will bounce back, but so does basic logic. Oil is a finite resource that we are using at an increasing rate, and as long as that situation remains, the laws of supply and demand mean that the price must recover. That is a good thing. As long as oil remains cheap there is little incentive to invest in the alternatives that we will inevitably need someday, nor to reduce our consumption of what is essentially a dirty fuel source. So, enjoy low fuel prices while you can, but don’t expect them to last forever.
The average fuel economy (window-sticker value) of new vehicles sold in the US in February was 25.2 mpg (9.33 l/100km)—down 0.2 mpg from January, according to the latest monthly analysis by University of Michigan Transportation Research Institute (UMTRI) researchers Dr. Michael Sivak and Brandon Schoettle. This decrease in fuel economy likely reflects the increased market share of light trucks, SUVs, and crossovers in response to the inclement winter weather in a large part of the country, they suggested.
Overall, vehicle fuel economy is up 5.1 mpg since October 2007 (the first month of their monitoring).
The monthly update of the University of Michigan Eco-Driving Index (EDI)—an index that estimates the average monthly emissions of greenhouse gases generated by an individual US driver—was delayed because of a delay in the release of the vehicle distance data by FHWA.
The NanoSteel Company (earlier post) has expanded its additive manufacturing (AM) material capabilities to support metal 3D printing of complex high-hardness parts and the ability to customize properties layer-by-layer through gradient material design. The company’s targeted markets for its AM powder portfolio are tool & die, energy, auto, and agriculture.
In September 2014, Nanosteel announced the expansion of the company’s engineered powders business into additive manufacturing. By leveraging the uniform metal matrix microstructures in the laser-sintering process, the company was able to build a crack-free, fully dense bulk sample. The company then leveraged this breakthrough in AM wear materials to print a bearing and impeller using the powder bed fusion process.
These parts were measured to be fully dense and crack-free, with hardness levels >1000 HV. These properties were achieved without the need for post-processing such as hot isostatic pressing (HIP) or further heat treatment, reducing production cost and lead times.
By delivering these properties in functional parts, NanoSteel said it took a significant step in the development of metal powders that enable affordable, robust industrial components produced on-demand through the 3D-printing process.
The company has now used a combination of high hardness and ductile alloys to create a part featuring a gradient design. NanoSteel worked with Connecticut Center for Advanced Technology to generate part samples using freeform direct laser deposition. This single additive manufacturing process achieved a seamless transition between the hard and ductile properties without subsequent heat treatment.
These gradient materials designs offer the equivalent of “digital case hardening”—delivering impact resistance and overall robustness in addition to high hardness and wear resistance in a single part.
By providing this capability, NanoSteel offers OEMs considerable design flexibility in meeting part-performance requirements while taking advantage of the operational efficiencies of AM including on-demand availability, less inventory and lower transportation costs.
Proprietary metal alloys that support the cost-effective 3D printing of high-quality parts will help accelerate the transition from subtractive to additive manufacturing across applications such as wear parts, bearings, and cutting tools. The company’s AM powder offerings make it possible to design exclusively for the function of a high hardness part, releasing designers from the limitations of conventional production processes and opening new opportunities to improve performance.—Harald Lemke, NanoSteel’s General Manager of Engineered Powders
Over its thirteen-year history, NanoSteel has created progressive generations of iron-based alloys from surface coatings to foils to powder metals and sheet steel. For the automotive industry, NanoSteel has achieved a significant breakthrough in the development of nano-structured sheet steel with exceptional strength and ductility. NanoSteel is a privately held company funded by lead shareholders EnerTech and Fairhaven Capital. GM Ventures also has a position in the company. (Earlier post.)
Opel introduced Opel OnStar at the Geneva Motor Show; OnStar will roll out across the company’s passenger car range from August 2015. The first introduction wave will see Opel OnStar introduced in 13 European markets with additional European markets following later. GM’s OnStar already connects around seven million customers in the US, Canada, China and Mexico.
Customers will be able to use the entire service portfolio provided by Opel OnStar as well as the high-speed Wi-Fi hotspot free of charge for the first 12 months after registration.
The 4G LTE connection enables a Wi-Fi hotspot, allowing up to seven devices to connect in and around the vehicle. The built-in 4G LTE structure is specifically designed for in-vehicle use as it is integrated into the vehicle’s electrical system and includes an external antenna to maximize coverage and connectivity. Customers will not be required to have a smartphone to use connected services. 4G LTE will initially be introduced in three markets, Germany, the UK and the Netherlands with the remaining countries following suit at a later stage.
In addition to the entertainment and working tool features, Opel OnStar is also there in case of an emergency. If an airbag deploys, Opel OnStar will be alerted automatically. An advisor will then contact the vehicle to determine whether help is required. If there is no response, emergency responders are immediately sent to the exact location of the vehicle. Opel OnStar Advisors located at the high-tech Opel OnStar service center in Luton, England, are available 24/7 and 365 days a year. The Opel OnStar buttons will be located in the overhead center console or the rear-view mirror on some cars. Furthermore, the new system also includes roadside assistance services.
Smartphone owners will be able to connect to their vehicle remotely with a smartphone app. It will enable them to:
Stolen vehicle assistance will enable Opel OnStar to work closely with law enforcement agencies to ensure that the car is recovered quickly and safely and returned to its rightful owner. Remote Ignition Block will allow Opel OnStar to send a remote signal to the vehicle that blocks the engine from starting once it has been reported stolen.
Opel OnStar can also provide subscribers with a monthly Vehicle Diagnostics email with the most important vehicle data and information. Furthermore, a diagnostics check can be requested at any time at the push of a button.
Opel said that its OnStar subscribers in Europe will be in complete control of their data and the Opel OnStar services they receive. Before the services are activated they will have to agree to the terms and conditions. Furthermore, they will be able to choose whether they want to reveal their current location—at a push of the Privacy Button their position will be masked. However, no matter whether the location is masked/unmasked Opel OnStar will not be used to monitor its user but will solely offer emergency services. In case of an airbag deployment, Opel OnStar will by default override the mask functionality so that emergency services can be dispatched to the exact location as quickly as possible.
Researchers at the University of Houston, with their colleagues at Boston College, have created a new thermoelectric material—germanium-doped magnesium stannide (Mg2Sn0.75Ge0.25)—intended to generate electric power from waste heat with greater efficiency and higher output power than currently available materials.
Traditionally, thermoelectric materials researchers have focused on a high thermoelectric figure-of-merit (ZT) as the only parameter pursued in thermoelectric materials for high conversion efficiency. In a paper published in Proceedings of the National Academy of Sciences (PNAS) describing the material, the researchers argue that a high power factor (PF) is equivalently important for high power generation, in addition to high efficiency.
Pursuing high ZT has been the focus of the entire thermoelectric community … However, for practical applications, efficiency is not the only concern, and high output power density is as important as efficiency when the capacity of the heat source is huge (such as solar heat), or the cost of the heat source is not a big factor (such as waste heat from automobiles, steel industry, etc.)—Liu et al.
The material was created through mechanical ball milling and direct current-induced hot pressing. It can be used with waste-heat applications and concentrated solar energy conversion at temperatures up to 300 ˚C, said Zhifeng Ren, lead author and M.D. Anderson Chair professor of physics at UH. Ren suggested typical applications would include use in a car exhaust system to convert heat into electricity to power the car’s electric system, boosting mileage, or in a cement plant, capturing waste heat from a smokestack to power the plant’s systems.
It was found that Mg2Sn0.75Ge0.25 has an average ZT of 0.9 and PF of 52 μW⋅cm−1⋅K−2 over the temperature range of 25–450 °C, a peak ZT of 1.4 at 450 °C, and peak PF of 55 μW⋅cm−1⋅K−2 at 350 °C. By using the energy balance of one-dimensional heat flow equation, leg efficiency and output power were calculated with Th = 400 °C and Tc = 50 °C to be of 10.5% and 6.6 W⋅cm−2 under a temperature gradient of 150 °C⋅mm−1, respectively.—Liu et al.
The figure of merit is fairly standard, but the power factor is high. That, coupled with a raw material cost of about $190 per kilogram, according to the US Geological Survey Data Series, makes it commercially viable, the researchers said.
Ren, along with frequent collaborator Gang Chen of the Massachusetts Institute of Technology and two former students, has formed a company called APower to commercialize the material.
Ren, who also is a principal investigator at the Texas Center for Superconductivity at UH, said several competing materials have lower power factors and also more expensive raw materials.
In addition to Ren, researchers on the paper include Weishu Liu, Hee Seok Kim, Shuo Chen, Qing Jie, Bing Lv and Paul Ching-Wu Chu, all of the UH physics department and the Texas Center for Superconductivity; Mengliang Yao, Zhensong Ren and Cyril P. Opeil of Boston College, and Stephen Wilson of the University of California at Santa Barbara.
Weishu Liu, Hee Seok Kim, Shuo Chen, Qing Jie, Bing Lv, Mengliang Yao, Zhensong Ren, Cyril P. Opeil, Stephen Wilson, Ching-Wu Chu, and Zhifeng Ren (2015) “n-type thermoelectric material Mg2Sn0.75Ge0.25 for high power generation” PNAS doi: 10.1073/pnas.1424388112
Renault has extended the range of its battery-electric ZOE to 149 miles (240 kilometers)—a boost of 19 miles (31 km), or 14.6%—in the New European Driving Cycle (NEDC) by using a new lighter and more compact R240 electric motor and an optimized electronic management system. (Earlier post.)
The R240 is a synchronous electric motor with rotor coil, with a power output of 65 kW and torque of 220 N·m (162 lb-ft). It also features a built-in Chameleon charger (earlier post) which allows faster charging at home (3 kW and 11 kW). The R240 is an all-Renault motor, designed by Renault engineers at the Technocentre R&D facility outside Paris and at the Cléon plant where the motor is made—close to Flins, where the ZOE is produced.
ZOE’s new R240 motor features improved performance (and consumes less energy), while offering a longer driving range and faster charging times. The new motor builds on Renault’s expertise in electric vehicles; 95 patents have been filed to date.
Two main areas of focus in the development were improved electronic management to cut electric energy consumption on the move and the new charging system to reduce charging times at low power levels. When designing the new motor, Renault focused on integrating components which have helped to cut the motor’s size by 10% without sacrificing performance. This opens up new opportunities for the motor to be fitted to smaller cars.
Modules are no longer stacked, having been replaced by fully integrated modules.
Smaller modules have been designed and assembled to meet precise requirements (gaps reduced between modules, external power cables removed).
An air cooling system is now used for the assembly (ducts between modules have been removed). Only the Power Electronic Controller is still water-cooled for its specific requirements.
The junction box, the power electronics unit and the Chameleon charger are now in a single unit called the Power Electronic Controller. The unit is 25% smaller as a result.
Renault is continuing its research into improving electric motor technology—the underlying goal of its involvement in the FIA Formula E Championship as both a technical partner to the series and the title sponsor of the e.dams-Renault team. By testing EV technology under extreme race conditions, this championship will help to speed up the progress of EV development in terms of both performance and range, the company said.
Global Bioenergies has produced “second-generation” isobutene, in a push to diversify accessible feedstock towards cheaper resources. As a first step in manufacturing bio-sourced isobutene, Global Bioenergies has been using first-generation feedstock such as wheat-derived glucose to set-up and to optimize its bio-isobutene process, which produces the gaseous hydrocarbon via fermentation. (Earlier post.) However, the process was designed to be versatile in terms of feedstock.
With the right technical adaptations, the process is suited to the usage of non-edible biomass feedstock such as wheat straw, corn stover, sugar cane bagasse or even wood chips.
Various companies are presently de-bottlenecking the conversion of second-generation materials into fermentable sugars. These technologies have now matured to commercial scale, with five plants having started operations in the last 24 months. This industry ultimately has the potential to provide fermentation processes with low-cost sugars derived from abundant resources.
Global Bioenergies recently established collaborations with nine companies from three continents developing the most promising technologies to convert various resources (straw, bagasse, wood...) into fermentable sugars.
Preliminary tests have resulted in successful second-generation isobutene production at the laboratory scale, with process performances similar to the ones observed using wheat-derived glucose.
Isobutene is used in the production of rubber for the tire industry and in plastics, anti-oxidants and fine chemicals. It is also used to produce polyisobutene, a starting product for lubricants, fuel additives, adhesives and sealants.
We have now demonstrated experimentally that our isobutene production process is compatible with a range of second generation resources. Using impurity-containing sugar solutions is usually difficult in classical fermentation processes that lead to liquid compounds, because the accumulation of such impurities in the culture broth makes purifying the product more complex. Our process, which is based on the production of a gaseous product, alleviates these issues and will allow us to use the cheapest types of feedstock.—Frédéric Pâques, Chief Operating Officer at Global Bioenergies
Global Bioenergies is one of the few companies worldwide, and the only one in Europe, that is developing a process to convert renewable resources into hydrocarbons through fermentation. The company initially focused its efforts on the production of isobutene, one of the most important petrochemical building blocks that can be converted into fuels, plastics, organic glass and elastomers. Global Bioenergies continues to improve the yield of its process and recently announced success with first testing in its industrial pilot. The company also replicated its achievement to propylene and butadiene two members of the gaseous olefins family, key molecules at the heart of petrochemical industry.
At the Geneva Motor Show, Toyota introduced the facelifted Auris. With the launch of the Auris Hybrid in 2010, Toyota became the first manufacturer to offer a choice of three powertrains (gasoline, gasoline-electric hybrid, and diesel) in the C-segment.
Reflecting both changes in the highly-competitive C-segment market and Toyota customer feedback, the 2015 Auris range features significant improvements in five key areas: Design; Sensory Quality; the Hybrid model; Safety; and, improving the model’s segment coverage by some 40%, Powertrains. As part of the change, an all-new, 1.2 liter direct injection turbocharged engine from Toyota’s new family of efficient engines announced last year (earlier post) joins the existing gasoline line-up.
The 2.0 liter turbo diesel has been replaced by a new 1.6 liter D-4D unit, and the 1.4 liter D-4D engine has been substantially upgraded, offering best-in-class CO2 emissions in the 90 hp category. A 1.8 liter hybrid powertrain completes one of the broadest ranges of engine choice for any model in this segment. Every engine in the range now meets Euro 6 emissions regulations.
The 2015 Auris range further benefits from suspension and steering revisions designed to improve ride comfort, handling and driver involvement. And numerous measures have also been introduced to reduce the transmission of Noise, Vibration and Harshness (NVH) into the cabin.
Toyota has also revised the Auris grade structure to bring Hybrid grades—Entry, Mid, Style and High—into line with the rest of the model range.
Lower full hybrid system emissions. The Hybrid model, with combined cycle fuel economy of 3.5 l/100 km (67 mpg US) currently accounts for more than 50% of all Auris sales in West Europe, a mix Toyota expects to grow further over the next few years. Since the hybrid powertrain was made available in the Auris range, more than 200,000 units have been sold. The Auris is the most sold hybrid in Europe.
The Auris full hybrid now returns CO2 emissions figures as low as a 79 g/km in the European homologation combined cycle.
Capable of operating both independently and in combination, the HSD system’s 1.8 liter VVT-i gasoline engine and electric motor generate a maximum power output of 136 DIN hp (101 kW), equipping the Auris Hybrid with a 0-100 km/h acceleration time of 10.9 seconds and a maximum speed of 180 km/h (112 mph).
The Auris Hybrid can drive for up to 2 km (1.24 miles) at speeds of up to about 50 km/h (31 mph), depending on battery charge and driving conditions.
1.2T: an all-new direct injection turbo gasoline engine. The all-new 1197cc, 16 valve, 4-cylinder, direct injection turbo gasoline engine offers a level of performance similar to the one of a 1.6 engine while its fuel consumption and CO2 emissions are lower. The 1.2T belongs to the range of 14 new engines that Toyota will launch globally between April 2014 and the end of 2015. (Earlier post.)
The new 4-cylinder 1.2T engine is the second engine from this new family to come to Europe under the Toyota brand, after the 3-cylinder 1.0 engine that went on sale in AYGO and Yaris last year. (Earlier post.) Like the 1.0, the 1.2T uses advanced technologies that allow the engine to change from the Otto-cycle to the Atkinson cycle under low loads, vertical vortex high tumble air flow intake ports, an exhaust manifold integrated in the cylinder-head and advanced heat management.
To this, the 1.2T adds a direct injection system, as well as a water-cooled turbo and heat-exchanger. Furthermore, the VVT-i (Variable Valve Timing – intelligent) system known from the 1.0, is upgraded to a VVT-iW (Variable Valve Timing - intelligent Wide) system, which allows even more flexibility in the valve-timing.
The combination of these technologies results in increased performance and efficiency. For a displacement of 1197cc, the engine delivers 116 DIN hp (85 kW) and a constant torque of 185 N·m (136 lb-ft) between 1500 and 4000 rpm. It will push the New Auris, the first model to which it is applied, from 0 to 100 km/h in 10.1 seconds. 5th gear acceleration from 80 to 120 km/h (50-75 mph) takes 13.7 seconds, and the top speed is set at 200 km/h (124 mpg). The car achieves 4.7 l/100 km (50 mpg) on the combined cycle, and delivers 109g/km of CO2.
Avoiding knock. The key to achieving outstanding fuel consumption without compromising performance, is to apply a higher compression. But generally, as the compression increases, so does the risk of uncontrolled combustion (knocking).
The 1.2T’s high compression ratio of 10:1 was made possible with the adoption of a series of key technologies that improve control over the combustion process. That way, the risk of knocking could be avoided.
First, the intake ports have been designed to generate a more intense flow and a vertical vortex; the shape of the piston also has been optimized to improve in-cylinder turbulence. As a result, fuel and intake air mix faster, and a more homogeneous mixture is formed. This leads to a higher combustion speed, which helps prevent knocking.
Advanced heat-management is in itself a great way to improve fuel economy, but it is also another way of reducing the risk of knocking. The engine was designed in such a way that the temperature of each individual part can be optimized. For example, the bottom of the pistons is cooled by oil-jets and the cooling of the cylinder head is separated from that of the engine block. This allows to reduce the temperature in the combustion chamber, whilst keeping the block itself hot enough to reduce friction.
Direct injection contributes as well, as it helps to dissipate the heat in the combustion chamber. And the charge air passes through the intercooler, which uses an independent low temperature cooling circuit.
Low-end torque and quick response. A low-inertia turbocharger, the VVT-iW valve system and the D-4T direct injection system work hand in hand to ensure excellent torque delivery from the lowest engine speeds. Together with the limited volume intake system, this ensures an immediate response to the accelerator pedal.
The compact injection system has been newly developed for the 1.2T engine, and was targeted for utilization in a small displacement engine. It allows multiple injections per cycle, and the optimized width and reduced length of the fuel spray ensure the quality of the combustion, regardless of the engine regime and load.
From Otto to Atkinson. The VVT-i (Variable Valve Timing - intelligent) system operates on both the intake and the exhaust side, and allows maximizing torque at all engine speeds. In addition, the new VVT-iW (Variable Valve Timing - intelligent Wide) allows for the intake valve closing to be delayed—meaning that the engine can operate in both the Otto and the Atkinson cycle.
The latter is used in extremely low load conditions, when the intake valve remains open for a fraction of time, after the compression stroke has set in, allowing part of the gas charge to be pushed back into the intake. As a result, the effective compression stroke is shortened. Pumping losses are reduced, since the pressure on the piston is lower, and also the throttle valve can be opened wider.
Quick and smooth Stop & Start. A new start control was developed to ensure a quick and smooth engine restart. When the system shuts down the engine, it controls the stop position to leave the piston half way in the compression stroke. Then, upon restart, it applies stratified injection in the first compressed cylinder to counter vibrations. And by retarding the ignition, torque increase is kept in check, preventing the engine from revving excessively, hence ensuring a confident and tranquil take-off.
New 1.6l D-4D. Making its first appearance in the Auris range, a new 1598 cc turbodiesel replaces the outgoing 2.0l unit. The new engine develops 112 DIN hp (84 kW) and maximum torque of 270 N·m (199 lb-ft) between 1750 and 2250 rpm. This equips the Auris 1.6 D-4D with performance figures of 0-100 km/h in 10.5 seconds, 80-120 km/h (50-75 mph) (in 5th gear) in 10.9 seconds, and a top speed of 190 km/h (118 mph).
Conversely, CO2 emissions are markedly lower than those of the outgoing 2.0 liter unit, falling to 104 g/km, and average fuel consumption is now only 4.1 l/100 km (57 mpg US). Auris 1.6 D-4D cost of ownership is further reduced by a new service scheme featuring a 20,000 km (12,427 miles) service interval.
Uprated 1.4l D-4D. The 1364 cc turbodiesel has been upgraded to be Euro 6 compliant, but the changes go significantly further than that. The unit features numerous enhancements to both improve performance and lower emissions. A new turbocharger reduces friction in the turbine shaft by 20%, and improves efficiency to generate a higher boost pressure at low engine speeds.
A new Solenoid fuel injection system features a larger supply pump and higher common rail injection pressures of 180 Mpa, making it compatible with the Euro 6 engine’s ECU and software. A NOx Storage Reduction (NSR) catalyst has been adopted within the exhaust system to meet the Euro 6 requirement for a 55% reduction in NOx.
A new piston design with an open chamber combustion bowl improves fuel economy by 3.4%. The new pistons feature a Diamond-like Carbon (DLC) coating which reduces friction to lower fuel consumption.
A new cylinder head cover is now fabricated in plastic for a 40% reduction in weight, and offers improvements to both camshaft lubrication and oil capture performance.
The uprated engine develops 66 kW / 90 DIN hp. The breadth of torque generation has been expanded 400 rpm lower down the rev range, with a maximum 205 N·m (151 lb-ft) now available from only 1,400 rpm, up to 2,800 rpm. The Auris 1.4D-4D will accelerate from 0-100 km/h in 12.5 seconds, and has a maximum speed of 180 km/h (112 mph).
Equipped with a manual transmission and Stop & Start technology, the improved 1.4 D-4D 90 unit now returns a combined cycle fuel consumption of 3.4 l/100 km (69 mpg US) and benefits from a substantial reduction in CO2 emissions to 89 g/km.
Multidrive S Continuously-Variable Transmission. Available on 1.2 turbo and 1.6 Valvematic gasoline versions of the Auris, Multidrive S is a continuously-variable transmission (CVT) with a fully automatic seamless shift mode or a sequential, stepped 7-speed Sport mode.
In Sport mode, the system is optimized for response and direct engine control, and the transmission step position can be selected by the gear lever, or by shift paddle. Sport mode also features precise cornering control. On detecting deceleration, the system downshifts and applies engine braking to assist the braking force. On corner exit, predictive downshift logic controls the system to ensure the optimal gear ratio is selected for the required level of acceleration.
Improved driving dynamics and NVH. The new, Auris range benefits from further suspension and steering revisions designed to improve ride comfort and handling. Numerous measures have also been introduced to reduce the transmission of Noise, Vibration and Harshness (NVH) into the cabin.
Components of the front MacPherson strut suspension have been revised, including the design of the coil spring, shock absorber, upper insulator, bound stopper and stabiliser bush.
The new, Auris features either a double wishbone or torsion beam rear suspension system. The double wishbone system equips all 1.2 liter turbo, 1.6 liter gasoline, 1.6 liter diesel and full hybrid models. 1.33 liter gasoline and 1.4 liter diesel engine models feature torsion beam rear suspension.
In combination, these front and rear suspension revisions improve initial roll damping, minimise friction and enhanced straight-line ride comfort.
In addition, the mapping of the Auris’ Electric Power Steering (EPS) has been tuned to further build steering weigh as vehicle speeds rise, giving improved feedback above speeds of 60-80 km/h (37-50 mph).
Due to growing requests from companies and fleets alike, Nissan hasadvanced the introduction of the latest iteration in its electric vehicle line-up—a seven-seat version of the all-electric e-NV200 van, and launched it at the Geneva Motor Show. (Earlier post.)
The e-NV200’s electric drivetrain, based on that used in the LEAF, is combined with the cargo volume of the NV200 to create a practical and versatile vehicle capable of carrying people or goods. Since the inception of the e-NV200, a seven-seat version of the electric van has always been part of Nissan’s plans, fulfilling an unmet need for an electric vehicle that can move a larger number of people.
From taxi fleets to shuttle services and even to large families, the seven seat e-NV200 Evalia offers a zero-emission solution. For those with a more regular need to move cargo and an occasional need for seven seats, the Combi version of the e-NV200 can also be specified with the larger seating capacity.
The seven-seat version of the e-NV200 is configured with two seats in the front, three in the middle and two in the rear. Both the second and third rows can be folded to allow for larger quantities of luggage to be carried, making the new variant a hugely flexible vehicle for commercial or private use. The second row rolls forward and the third row folds to the sides to open up 2.94 cubic metres of cargo capacity, which is enough to transport three bicycles with the wheels in place, unique in this class.
With all three rows in place, the luggage capacity is 443 liters under the tonneau cover, and up to an impressive 870 liters when measured to the roof line, allowing the possibility to carry seven people and a large volume of luggage.
To increase passenger comfort the seven-seat passenger version comes equipped with additional rear air conditioning to ensure a more even temperature through the cabin, even for those in the third row of seating.
The new model is available with the CHAdeMO quick charging system, which gives the access to the most widely installed rapid charging system in Europe today with more than 1,500 accessible points. The quick charging option allows businesses or drivers to extend journeys or do multiple short journeys in a day with a quick top up.
One of the main obstacles to the commercialization of high-energy density lithium-sulfur batteries is the tendency for lithium polysulfides—the lithium and sulfur reaction products—to dissolve in the battery’s electrolyte and travel to the opposite electrode permanently. This causes the battery’s capacity to decrease over its lifetime.
To prevent this polysulfide shuttle, researchers in the Bourns College of Engineering at the University of California, Riverside have fabricated SiO2-coated sulfur particles (SCSPs) for cathode material. With the addition of mildly reduced graphene oxide (mrGO) to the material, SCSPs maintain more than 700 mAh g−1 after the 50th cycle. A paper on their work is published in the RSC journal Nanoscale.
The silica shell functions as a trapping barrier for the polysulfides; the team used an organic precursor to construct the trapping barrier.
Our biggest challenge was to optimize the process to deposit SiO2—not too thick, not too thin, about the thickness of a virus.—Mihri Ozkan, co-corresponding author
A schematic illustration of the process to synthesize silica-coated sulfur particles. Click to enlarge.
Graduate students Brennan Campbell, Jeffrey Bell, Hamed Hosseini Bay, Zachary Favors, and Robert Ionescu in Cengiz Ozkan’s and Mihri Ozkan’s research groups (earlier post) found that silica-caged sulfur particles provided a substantially higher battery performance, but felt further improvement was necessary because of the challenge with the breakage of the SiO2 shell.
We have decided to incorporate mildly reduced graphene oxide (mrGO), a close relative of graphene, as a conductive additive in cathode material design, to provide mechanical stability to the glass caged structures.—Cengiz Ozkan, co-corresponding author
The resulting cathode material combines both a polysulfide-trapping barrier and a flexible graphene oxide blanket that harnesses the sulfur and silica together during cycling.
The design of the core-shell structure essentially builds in the functionality of polysulfide surface-adsorption from the silica shell, even if the shell breaks. Incorporation of mrGO serves the system well in holding the polysulfide traps in place. Sulfur is similar to oxygen in its reactivity and energy yet still comes with physical challenges, and our new cathode design allows sulfur to expand and contract, and be harnessed.— Brennan Campbell
The work was funded by the Winston Chung Global Energy Center at UC Riverside.
Brennan Campbell, Jeffrey Bell, Hamed Hosseini Bay, Zachary Favors, Robert Ionescu, Cengiz S. Ozkan and Mihrimah Ozkan (2015) “SiO2-coated sulfur particles with mildly reduced graphene oxide as a cathode material for lithium–sulfur batteries” Nanoscale doi: 10.1039/C4NR07663J
Audi and AT&T announced that 2016 model year Audi vehicles will offer AT&T 4G LTE or 3G coverage. AT&T and Audi enabled the first-ever in-vehicle 4G LTE data connection in North America in 2014.
Under the agreement, all 2016 models with Audi connect will be delivered to customers with an AT&T SIM card providing connectivity to the AT&T wireless network.
Audi has previously said it plans to deploy 4G LTE network connectivity across its model lineup as new or refreshed models come to the market. In addition to its 4G LTE network being the nation’s most reliable, AT&T said that the network has the nation’s strongest LTE signal.
The new A6, A7, and TT models coming this year will feature the most advanced version of Audi connect including up-to-the-minute traffic information, semi-dynamic route guidance, over the air map updates, and internet radio, in addition to picture navigation, social media, personalized RSS news feeds with read-aloud functionality, and more.
The new Audi connect 4G LTE service will allow faster Google Earth and Google Street View enhancements to MMI navigation plus. The 4G LTE connectivity will also provide new Audi A6, A7, and TT customers faster downloads and high-definition video streaming for up to eight devices used by passengers over the in-vehicle Wi-Fi hotspot.
An accompanying mobile app will allow advanced functionality between the MMI system and smartphones.
Audi will add convenience by offering a Mobile Share data plan option to AT&T wireless customers who would like to add their vehicle to their existing smartphone or tablet data plan.