Impacts of the Properties of Anode Solid Electrolyte Interface on the Storage Life of Li-Ion Batteries

Storage life is critically important in applications of rechargeable batteries. The Li loss in graphite is the main cause during storage aging at a full state of charge while the solid electrolyte interface on the graphite acts as a protective layer to restrain the Li loss during aging. Focusing on the initial SEI electronic resistance as the rate-limiting factor during the aging progress, we investigated the properties of the SEIs formed under varied conditions. The main SEI components and corresponding electronic conductivity were analyzed, while the thicknesses of initial SEIs were estimated at the same time. The storage performance results confirmed that cells with high electronic resistance SEIs would have extended storage lifespan, but the performance should be based on well-formed SEIs. Cells with incomplete SEIs would have accelerated capacity loss rate during storage aging.