Energy Storage for Portable and Stationary Application: Materials Limitations

On January 8, I spoke at Applied Materials headquarters in Santa Clara, California to a packed room about the status of electrical energy storage. Energy storage is the limiting technology for renewable energy, such as wind and solar, and particularly for the next generation of hybrid electric vehicles, the plug-in hybrid electric vehicle (PHEV). If long-lived, low cost and safe batteries or capacitors are to be developed, a range of materials limitations must be overcome. The presentation discussed the present status of materials, both bulk and nano, for the next generation of batteries, with an emphasis on the anodes and cathodes for lithium-ion batteries.

The challenge facing the United States (U.S.) is how to become competitive in the energy storage area, when presently essentially all advanced batteries are made in Asia. This is despite the fact that the original IP is essentially all U.S. or the United Kingdom in origin. The answer might lie in advances in new materials and new battery systems that will leap-frog the capabilities of the present high-cost lithium-ion cells. Then, of course, retain the technology in the U.S. through appropriate carrots and sticks.

The materials challenges that need addressing are new anodes and cathodes that will store about double the energy of today’s carbon anodes and oxide cathodes. But beyond the materials themselves, lower cost manufacturing methods need to be developed not only in the synthesis of the raw materials but also in the assembly of the cells and batteries. These will be major challenges as the materials go nano, with their low densities, and lifetimes of 10 years are demanded at costs of no more than $250/kWh. There may be special market niches, where the cost curve can be lowered before the mass production scale is attained. Such niches include buses (which run around $500,000 each), and short-term load leveling. For the latter to be successful, it will need U.S. Federal incentives to get the utilities to work together and jump start the Smart Grid.