Stanford team reports progress toward stable Li-metal anode for high-energy-density batteries
… to make viable Li metal anodes, two fundamental challenges would need to be resolved: (1) accommodating the large change in electrode volume during cycling (unlike graphite and silicon anodes, where lithiation produces volume changes of ∼10% and 400%, respectively, Li metal is ‘hostless’ and its relative volumetric change is virtually infinite); and (2) controlling the reactivity towards the electrolyte (Li is one of the most electropositive elements). … One problem lies in the fact that the SEI layer cannot withstand mechanical deformation and continuously breaks and repairs during cycling. As a result, Li metal batteries have low Coulombic efficiency (80–90% for carbonate solvents and 90–95% for ether solvents) and low cycle life due to the rapid loss of Li and electrolyte in the continuous formation/dissolution of the SEI. A second problem is that Li deposition is not...