This month, Silicon Valley and San Francisco Bay Area companies Applied Materials, Amprius, Seeo and Nanosys received almost twenty million dollars in grants from the Department of Energy (DOE) for their developments in battery technologies for application in electric vehicles. The DOE has recently awarded new and additional grants, totaling $175 million, in emerging vehicle efficiency technologies and a total of $50 million were allocated to projects advancing storage initiatives in electric transportation.
One of the impediments in mass adoption of electric vehicles (EVs) is due to energy storage capabilities, i.e. limited battery capacity and range, battery weight, and cost. Energy storage in electric transportation presents a trade-off: smaller batteries will require frequent charging and the availability and accessibility to charging infrastructure, on demand. On the other hand, bigger batteries are heavy and expensive. Lithium-ion, also called Li-ion or LIB, is the current preferred storage technology. Typically, most EVs today can travel about 100 miles on lithium-ion batteries, but Li-ion cells aren’t light enough to travel 500 miles on a single charge and aren’t realistically economical for an average family car. In fact, batteries are the most expensive component of electric motors.
Although there has been a progress in lithium-ion expertise, the DOE’s grants focus on the next generation of battery technologies and the ability to successfully commercialize them. A number of companies and research establishments have been working in the US, Europe and Asia on developing high-density batteries with a relative fast charge and discharge capabilities, which can hold energy content that is comparable to gasoline tanks in conventional cars. New innovations are currently under development and aren’t available commercially yet. Several silicon-based technologies are destined to replace the expensive lithium-ion batteries, such as lithium-sulfur, lithium-air and metal air.
Utilization of silicon-based anodes in lithium-ion cells will likely to occur in 2012 and these will replace the carbon-based anodes used today. The silicon-based anodes have a higher energy capacity, however silicon is a very difficult material to work with in storage applications. Silicon has the tendency of to crack and swell during operation with lithium, rendering battery life-cycle issues. The lithium sulfur (Li-S) battery has a high storage density and is relatively light. The low price of sulfur results in a cost effective solution for electric transportation. The lithium-air battery uses electrochemistry combined with oxygen and it has a higher energy density than today’s lithium ion batteries. Other advantages include an air (i.e. lighter) cathode and the utilization of oxygen from the air. Metal air batteries and zinc-air fuel cells are electro-chemical batteries powered by oxidizing zinc with oxygen from the air. They have high density and are relatively inexpensive to produce. Metal air batteries are also developed in several sizes from small button cells for hearing aids to large size batteries for electric cars.
Read more about silicon-based battery innovation.
In 2009 IBM started the Battery 500 project to develop a new type of lithium-air battery technology to improve energy density dramatically. At the Nanoscale Science & Technology Program at the IBM Almaden Research lab in San Jose, California, nanoscience is used to boost storage capacity. The lab has been working on developing lithium-air batteries that can be comparable to a gasoline performance. This approach will reduce the need for comprehensive public and accessible charging infrastructure. The idea is to couple small lithium-ion batteries for starting the vehicle and for acceleration surges with larger lithium-air storage for use while driving.
Development of nanostructured silicon electrodes for lithium batteries is also in process in the US and abroad. To reduce fragility of the silicon-based battery applications, Nanostructuring gives silicon flexibility when strained during operation due to repeated swelling and contracting, therefore allowing it to recharge without cracking or deteriorating fast. Researchers at Amprius have used Stanford University professor Yi Cui’s (Department of Materials Science and Engineering) work on using nanostructured silicon films in lithium technologies. In trials, Amprius models have been tested through a few hundreds of charging cycles and have been shown to store twice the energy of a conventional battery. Further, silicon anodes can store three times more energy than carbon anodes by weight. However, additional testing is required.
Another San Francisco Bay Area company is Envia Systems, which is developing a high-capacity battery that offers a significant improvement of energy density at the cell level over what’s on the market today. General Motors, the maker of the Chevy Volt, has invested this year in Envia. Envia’s batteries use a layered composite-cathode technology that is manganese rich that allows to hold more charge. Currently, Chevy Volt uses lithium-ion batteries made with lithium-manganese-based cathodes, which also help extend the life of the battery.
Additional battery developments come from Massachusetts Institute of Technology (MIT) in Cambridge, MA, where researchers work on super-thin batteries that have high storage density, but also charge and discharge quickly. Here, the researchers use carbon nanotubes as electrodes, which have great thermal conductivity and mechanical and electrical properties.
There are several interesting developments in Sweden: Volvo research and development engineers are working on batteries designed primarily for electric transportation, plug-in and hybrids. This thin battery technology can be spread over a large surface and can fit in the panels of the car, the doors, and the hood. In addition to usage in automobiles, this technology could be applied in hybrid airplanes, where thin batteries can be placed on the wings and the body of the aircraft. Also in Sweden, at the Uppsala University, batteries with electrodes made from algae cellulose were developed. Utilizing algae, a cheap and renewable source, will reduce storage costs dramatically. However, since algae have low energy density, the cellulose electrode is coated with a conducting polymer. Further development to increase storage capacity in algae is in progress.
We are likely to have several battery breakthroughs in the near future. Online job boards post various scientific and research openings with required backgrounds in materials, chemistry, physics and more.
Check for battery/storage employment opportunities:
3. Lithium – opportunities