Energy Storage

Improving the batteries for electric drive vehicles, including hybrid electric (HEV) and plug-in electric (PEV) vehicles, is key to improving vehicles' economic, social, and environmental sustainability. In fact, transitioning to a light-duty fleet of HEVs and PEVs could reduce U.S. foreign oil dependence by 30-60% and greenhouse gas emissions by 30-45%, depending on the exact mix of technologies. For a general overview of electric drive vehicles, see the DOE's Alternative Fuel Data Center's pages on Hybrid and Plug-in Electric Vehicles and Vehicle Batteries.

While a number of electric drive vehicles are available on the market, further improvements in batteries could make them more affordable and convenient to consumers. In addition to light-duty vehicles, some heavy-duty manufacturers are also pursuing hybridization of medium and heavy-duty vehicles to improve fuel economy and reduce idling.

The Vehicle Technologies Office's Contribution

The Vehicle Technologies Office focuses on reducing the cost, volume, and weight of batteries, while simultaneously improving the vehicle batteries' performance (power, energy, and durability) and ability to tolerate abuse conditions. Reaching the Office's goals in these areas and commercializing advanced energy storage technologies will allow more people to purchase and use electric drive vehicles. It will also help the Department of Energy meet the EV Everywhere Grand Challenge goal of making the U.S. become the first nation in the world to produce plug-in electric vehicles that are as affordable for the average American family as today's gasoline-powered vehicles within the next 10 years.

The Vehicle Technologies Office pursues three major areas of research in batteries:

• Exploratory Battery Materials Research: Addresses fundamental issues of materials and electrochemical interactions associated with lithium and beyond-lithium batteries. This research attempts to develop new and promising materials, use advanced material models to predict the modes in which batteries fail, and employ scientific diagnostic tools and techniques to gain insight into why materials and systems fail. Building on these findings, it works to develop ways to mitigate those failures.
• Applied Battery Research: Focuses on optimizing next generation, high-energy lithium ion electrochemistries that incorporate new battery materials. The activity emphasizes identifying, diagnosing, and mitigating issues that negatively impact the performance and life of cells using advanced materials.
• Advanced Battery Development, System Analysis, and Testing: Focuses on the development of robust battery cells and modules to significantly reduce battery cost, increase life, and improve performance. This research aims to ensure these systems meet specific goals for particular vehicle applications.

These research and development activities are described at the Annual Merit Review and Progress Reports.

This research builds upon decades of work that the Department of Energy has conducted in batteries and energy storage. Research supported by the Vehicle Technologies Office led to today's modern nickel metal hydride batteries, which nearly all first generation hybrid electric vehicles used. Similarly, the Office's research also helped develop the lithium-ion battery technology used in the Chevrolet Volt, the first commercially available plug-in hybrid electric vehicle. This technology is now being used in a variety of hybrid and plug-in electric vehicles coming on the market now and in the next few years, including the Ford Focus EV.

Partnerships

The batteries subprogram works extensively with a number of different organizations, including national laboratories and universities. Within the Department, the office collaborates with the Office of Science and ARPA-e (Advanced Research Projects Agency-Energy). Across the federal government, the subprogram works with:

• The Interagency Advanced Power Group
• The Environmental Protection Agency
• The National Aeronautics and Space Administration
• The National Science Foundation
• The National Highway Traffic Safety Administration (Department of Transportation)
• The U.S. Army Tank, Automotive Research and Development and Engineering Center (Department of Defense)

They also collaborate on international research with:

• International Energy Agency's Implementing Agreement on Hybrid Electric Vehicles
• The Clean Energy Ministerial's Electric Vehicle Initiative
• The Clean Energy Research Center bilateral agreement between the US and China.

Much of the subprogram's research is conducted in sync with industry partners through:

• The U.S. DRIVE Partnership focusing on light-duty vehicles
• The 21st Century Truck Partnership, focusing on heavy-duty vehicles
• The United States Advanced Battery Consortium (USABC), a partnership between the U.S. Department of Energy (DOE), Chrysler, Ford, and General Motors to develop and demonstrate advanced battery technologies for hybrid and electric vehicles, as well as benchmark test emerging technologies.

Goals

As described in the EV Everywhere Blueprint, the major goals of the Batteries and Energy Storage subprogram are by 2022 to:

• Reduce the production cost of an electric vehicle battery to a quarter of its current cost
• Halve the size of an electric vehicle battery
• Halve the weight of an electric vehicle battery

Achieving these goals would result in:

• Lowering battery cost from $500/kwh to $125/kwh
• Increasing density from 100 Wh/kg to 250 Wh/kg, 200 Wh/l to 400 Wh/l, and 400 W/kg to 2000 W/kg