Large plastic Li-ion (PLI) cells (25–28Ah) have been fabricated for electric vehicle (EV) applications. The 28Ah cells show high specific energy (160Wh/kg), high specific power (526W/kg), excellent round-trip energy efficiency (92%), and a low self-discharge rate (6% in 30 days). A 25Ah cell of an earlier design has a good cycle-life of up to 750 cycles at 100% depth-of-discharge (DOD) to 80% of its initial capacity. Cycle-life tests of a 28Ah cell of a later design is in progress. Preliminary safety tests have also been carried out using 6Ah cells of a similar electrode design. These give very encouraging results for the development of a safe, high-energy PLI battery for EV duty.