I-Corps: Reusing Electric Vehicle Batteries for Low-Cost Energy Storage

University Of California-Davis, Davis CA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the large-scale reuse of electric vehicle batteries in low-cost, stationary energy storage systems. Society is becoming increasingly dependent on batteries. Electric vehicles, which are powered exclusively by batteries, represent an increasing share of total vehicle sales. Similarly, large, stationary batteries are now commonly connected to electric grids to increase the affordability and reliability of electricity. Over 75% of an electric vehicle battery's original capacity typically remains at the end of its useful life in a vehicle, and recycling the batteries is expensive and inefficient. To defer the expense of recycling and reduce e-waste, electric vehicle batteries may instead be reused for years more. Reuse would also limit the nation's dependence on imported batteries and the precious metals required to manufacture them. Finally, reused batteries can meet a critical market need for affordable energy storage. Electric utilities and grid operators demand energy storage to reduce the cost of providing reliable electricity. This demand will grow as variable, renewable electricity generators (e.g. wind turbines and solar panels) continue to gain popularity. Similarly, consumers demand energy storage for backup power and to reduce their electricity bills. This I-Corps project will further develop a technology which enables the safe, efficient, low cost reuse of electric vehicle batteries. The technology reduces the time required to test used batteries, optimizes used battery reassembly, and improves used battery performance. The algorithms accurately measure the health of individual battery cells in minutes, rather than hours. Then, the algorithms optimize the reconfiguration of used battery cells, which increases the efficiency and longevity of used battery systems. Finally, the system equips the used batteries with advanced control systems, which account for variable battery characteristics to further extend lifetime and boost efficiency. These capabilities have enabled a commercial-scale demonstration system. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.