Oxidation state of cross-over manganese species on the graphite electrode of lithium-ion cells

摘要: It is well known that Li-ion cells containing manganese oxide-based positive electrodes and graphite-based negative suffer accelerated capacity fade, which has been attributed to the deposition of dissolved on graphite during electrochemical cell cycling. However, reasons for fade are still unclear. This stems, in part, from conflicting reports oxidation state species electrode. In this communication, deposited probed by X-ray absorption near edge spectroscopy (XANES). The XANES features confirm, unequivocally, presence fully reduced (Mn0) surface particles. Mn0 electrode acts as a starting point understand consequent behavior these electrodes; possible degradation performance proposed discussed.