Batteries for Electrical Energy Storage in Transportation
The U.S. spends nearly a $1 billion per day to import petroleum, but we need dramatically better batteries for electric and plug-in hybrid vehicles (EV/PHEV) to truly compete with gasoline-powered cars. The projects in ARPA-E's BEEST program, short for "Batteries for Electrical Energy Storage in Transportation," could make that happen by developing a variety of rechargeable battery technologies that would enable EV/PHEVs to meet or beat the price and performance of gasoline-powered cars, and enable mass production of electric vehicles that people will be excited to drive.
For a detailed technical overview about this program, please click here.
Semi-Solid Flow Cells for Automotive and Grid-Level Energy Storage
Scientists at 24M are crossing a Li-Ion battery with a fuel cell to develop a semi-solid flow battery. This system relies on some of the same basic chemistry as a standard Li-Ion battery, but in a flow battery the energy storage material is held in external tanks, so storage capacity is not limited by the size of the battery itself. The design makes it easier to add storage capacity by simply increasing the size of the tanks and adding more paste. In addition, 24M's design also is able to extract more energy from the semi-solid paste than conventional Li-Ion batteries. This creates a cost-effective, energy-dense battery that can improve the driving range of EVs or be used to store energy on the electric grid.
Novel High Energy Density Lithium-Ion Cell Designs via Innovative Manufacturing Process Modules for Cathode and Integrated Separator
Applied Materials is developing new tools for manufacturing Li-Ion batteries that could dramatically increase their performance. Traditionally, the positive and negative terminals of Li-Ion batteries are mixed with glue-like materials called binders, pressed onto electrodes, and then physically kept apart by winding a polymer mesh material between them called a separator. With the Applied Materials system, many of these manually intensive processes will be replaced by next generation coating technology to apply each component. This process will improve product reliability and performance of the cells at a fraction of the current cost. These novel manufacturing techniques will also increase the energy density of the battery and reduce the size of several of the battery's components to free up more space within the cell for storage.
Missouri University of Science and Technology
High Performance Cathodes for Lithium-Air Batteries
Researchers at Missouri S&T are developing an affordable lithium-air (Li-Air) battery that could enable an EV to travel up to 350 miles on a single charge. Today's EVs run on Li-Ion batteries, which are expensive and suffer from low energy density compared with gasoline. This new Li-Air battery could perform as well as gasoline and store 3 times more energy than current Li-Ion batteries. A Li-Air battery uses an air cathode to breathe oxygen into the battery from the surrounding air, like a human lung. The oxygen and lithium react in the battery to produce electricity. Current Li-Air batteries are limited by the rate at which they can draw oxygen from the air. The team is designing a battery using hierarchical electrode structures to enhance air breathing and effective catalysts to accelerate electricity production.
Low-Cost Rechargeable Magnesium Batteries with High Energy Density
Pellion Technologies is developing rechargeable magnesium batteries that would enable an EV to travel 3 times farther than it could using Li-ion batteries. Prototype magnesium batteries demonstrate excellent electrochemical behavior, delivering thousands of charge cycles with very little fade. Nevertheless, these prototypes have always stored too little energy to be commercially viable. Pellion Technologies is working to overcome this challenge by rapidly screening potential storage materials using proprietary, high-throughput computer models. To date, 12,000 materials have been identified and analyzed. The resulting best materials have been electrochemically tested, yielding several very promising candidates.
Planar Energy Devices, Inc.
Solid-State Large Format All Inorganic Lithium Batteries
Planar Energy is developing a new production process where lithium-ion batteries would be printed as a thin film onto sheets of metal or plastic. Thin-film printing methods could revolutionize battery manufacturing, allowing for smaller, lighter, and cheaper EV batteries. Typically, a battery's electrolyte--the material that actually stores energy within the cell--is a liquid or semi-liquid; this makes them unsuitable for use in thin-film printing. Planar is working with a ceramic-based gel electrolyte that is better suited for printing. The electrolyte would be printed onto large reels of metal or plastic along with other battery components. Once printed, these reels can be cut up into individual cells and wired together to make battery packs. By reducing packaging materials with this unique production process, Planar's efficient Li-Ion battery design would allow more space for storing energy--at a far lower cost--than today's best Li-Ion battery designs.
PolyPlus Battery Company
Development of Ultra High Specific Energy Rechargeable Lithium-Air Batteries Based on Protected Lithium Metal Electrodes
PolyPlus is developing the world's first commercially available rechargeable lithium-air (Li-Air) battery. Li-Air batteries are better than the Li-Ion batteries used in most EVs today because they breathe in air from the atmosphere for use as an active material in the battery, which greatly decreases its weight. Li-Air batteries also store nearly 700% as much energy as traditional Li-Ion batteries. A lighter battery would improve the range of EVs dramatically. PolyPlus is on track to making a critical breakthrough: the first manufacturable protective membrane between its lithium-based negative electrode and the reaction chamber where it reacts with oxygen from the air. This gives the battery the unique ability to recharge by moving lithium in and out of the battery's reaction chamber for storage until the battery needs to discharge once again. Until now, engineers had been unable to create the complex packaging and air-breathing components required to turn Li-Air batteries into rechargeable systems.
High Energy Density Capacitors
Recapping is developing a capacitor that could rival the energy storage potential and price of today's best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.
Revolt Technology, LLC
Zinc Flow Air Battery (ZFAB), The Next Generation of Energy Storage for Transportation
ReVolt is developing a rechargeable zinc-air battery that could offer 300-500% more storage capacity than today's Li-Ion batteries at half their cost. Zinc-air batteries could be much more inexpensive, lightweight, and energy dense than Li-Ion batteries because air--one of the battery's main reactants--does not need to be housed inside the battery. This frees up more space for storage. Zinc-air batteries have not been commercially viable for use in EVs because they typically cannot be recharged, complicating vehicle "refueling". ReVolt has designed a system whereby the battery's zinc-based negative electrode is suspended in liquid and passed through a tube that functions as the battery's positive electrode. This allows the device to charge and discharge just like a regular battery.
Sila Nanotechnologies, Inc.
Doubling the Energy Density Anodes of Lithium-Ion Batteries for Transportation
Sila is developing a high-throughput technology for scalable synthesis of high-capacity nanostructured materials for Li-Ion EV batteries. The successful implementation of this technology will allow improvements in energy storage capacity of today's best batteries at half the cost. In contrast to other high-capacity material synthesis technologies, Sila's materials show minimal volume changes during the battery operation, which is a key challenge of next-generation battery anode materials. In addition, Sila's technology may allow for the dramatic enhancements of the batteries' cycle life, structural stability, safety, and charging rate. The low-cost, drop-in compatibility with existing cell manufacturing technologies, and environmental friendliness of both the material synthesis and electrode fabrication will assist in the rapid adoption of Sila's technology. Coupling increased battery capacity with substantial cost reduction could alleviate the driving range anxiety and price problems associated with today's EVs. Increasing the capacity of battery electrodes is critical to lowering the cost of Li-Ion batteries and making EVs cost-competitive with gasoline-based vehicles.
Sion Power Company
Development of High Energy Lithium-Sulfur Cells for Electric Vehicle Applications
Sion Power is developing a lithium-sulfur (Li-S) battery, a potentially cost-effective alternative to the Li-Ion battery that could store 400% more energy per pound. All batteries have 3 key parts--a positive and negative electrode and an electrolyte--that exchange ions to store and release electricity. Using different materials for these components changes a battery's chemistry and its ability to power a vehicle. Traditional Li-S batteries experience adverse reactions between the electrolyte and lithium-based negative electrode that ultimately limit the battery to less than 50 charge cycles. Sion Power will sandwich the lithium- and sulfur-based electrode films around a separator that protects the negative electrode and increases the number of charges the battery can complete in its lifetime. The design could eventually allow for a battery with 400% greater storage capacity per pound than Li-Ion batteries and the ability to complete more than 500 recharge cycles.
The All-Electron Battery: A Quantum Leap Forward in Energy Storage
Stanford is developing an all-electron battery that would create a completely new class of energy storage devices for EVs. Stanford's all-electron battery stores energy by moving electrons rather than ions. Electrons are lighter and faster than the ion charge carriers in conventional Li-Ion batteries. Stanford's all-electron battery also uses an advanced structural design that separates critical battery functions, which increases both the life of the battery and the amount of energy it can store. The battery could be charged 1000s of times without showing a significant drop in performance.
Low-Cost Transportation Batteries
Xilectric is developing a totally new class of low-cost rechargeable batteries with a chemistry analogous to the original nickel-iron Edison battery. At the turn of the 20th century, Thomas Edison experimented with low-cost, durable nickel-iron aqueous batteries for use in EVs. Given their inability to operate in cold weather and higher cost than lead-acid batteries, Edison's batteries were eventually dismissed for automotive applications. Xilectric is reviving and re-engineering the basic chemistry of the Edison battery, using domestically abundant, environmentally friendly, and low-cost metals, such as aluminum and magnesium, as its active components. Xilectric's design would be easy to manufacture and demonstrate longer life span than today's best Li-ion batteries, enabling more widespread use of EVs.