South 8 completes testing of LiGas liquified gas battery cell electrolyte

New battery chemistry promises improved cold and warm weather performance (Photo: Adobe Stock)

South 8 Technologies has reported completing a successful demonstration of its LiGas liquified gas electrolyte with low-nickel, cobalt-free battery cells.

The LiGas electrolyte uses widely available non-toxic and non-corrosive gases which are held under pressure in a liquified state. The company said that this electrolyte can be contained in standard cylindrical cells.

The California-based company said that the LiGas electrolyte has already shown ‘excellent performance’ in conventional graphite/lithium-nickel-manganese-cobalt oxide (LNMO) cells.

Cold-weather performance is said to be enhanced using the LiGas electrolyte, which also supports faster charging than standard cells.

As part of the development process, South 8 demonstrated full compatibility with a 4.6 V commercial LNMO cathode. Energy retention at -20C (-4F) was measured at 96%. This compares to less than 5% retention for standard liquid LNMO electrolyte at the same temperature. Further testing showed 87% energy retention at -40C.

“LNMO is a future cathode material, promising the safety of LFP (lithium iron phosphate) and energy of NMC (nickel manganese cobalt),” said Cyrus Rustomji, Chief Science Officer at South 8. “The challenge has been the electrolyte: conventional solutions break down at LNMO’s high voltage. LiGas does not. LiGas gives excellent low temperature performance and greatly reduces thermal propagation.”

A further goal of the project is to deliver a battery format which can help to reduce the overall cost of electric vehicles, while also improving cell safety levels.

Development work is being supported by funding from the US Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), through the EVs for American Low-Carbon Living (EVs4ALL) program.