Both of GM’s battery partners for the Volt—Compact Power, Inc. (CPI) and Continental/A123Systems—have marked more progress on their respective development of lithium-ion battery packs for the Chevrolet Volt extended range electric vehicle (EREV).
Concurrent with EVS-23, Compact Power delivered its second battery pack to the GM team. They had delivered the first pack on 31 October. (Earlier post.) CPI cells use a proprietary lithium manganese spinel (LiMn2O4) material for its cathode with additives to improve calendar life under high temperature conditions. A ceramic coating on the separator (the safety-reinforced separator, SRS) minimizes potential thermal runaway due to an internal short. CPI uses a prismatic format for its cells.
In its work with GM, CPI is adjusting the mix of the cathode material with the intention of strongly increasing the energy density of its cells, according to Dr. Prabhakar Patil, CEO, while retaining the safety aspects of its chemistry, packaging and management.
Separately, A123Systems showed off its new prismatic cell being developed for the Volt—without providing any public technical detail—at its booth at EVS-23. A123Systems uses a doped nanophosphate technology for the cathode and to date has used a cylindrical format for its cells.