Cobalt (Co) is a major component of lithium (Li)-ion batteries for electric vehicle (EV) and other applications, but dependence on its inclusion in these power devices is deemed problematic due to its anticipated scarcity as well as associated supply chain risks. These concerns may be eliminated with a new Li-ion battery design that pairs a Co-free cathode with a silicon (Si) suboxide anode.

University of Tokyo researchers combine Li, nickel, manganese, Si and oxygen in the new electrode architecture. The electrolyte design based on Li-fluorine-Si/ 2,2,2-trifluoroethyl methyl carbonate (FEMC features a shifted potential, which serves to aid formation of robust passivation layers on the anode and promote electrolyte stability against both reductive and oxidative degradation.

An additional benefit of this new system is an energy density about 60% higher than that of conventional Li-ion batteries. This could translate into longer service life while delivering 4.4 V relative to the 3.7 V provided by conventional nickel-manganese-Co batteries.

During testing, batteries with the new chemistry were able to fully charge and discharge over 1,000 cycles, simulating three years of full use and charging. Only about 20% of storage capacity was lost as a result of such cycling.

Research describing this sustainable approach to high-performing Li-ion batteries is published in Nature Sustainability.

To contact the author of this article, email shimmelstein@globalspec.com