Concentrated electrolyte boosting high-temperature cycling stability of LiCoO 2 /graphite cell

We report a strategy employing a concentrated electrolyte to boost the cycling stability of LiCoO2/graphite cells at 90 °C for the first time. Such a concentrated electrolyte provides the cells with superb cycling stability (97% after 160 cycles) at 90 °C. Further investigations unveil that the concentrated electrolyte participates in the formation of a compact LiF-rich CEI layer, which effectively inhibits the decomposition of electrolyte solvent and the dissolution of Co2+, maintaining the structural integrity of the LiCoO2 cathode.