Enhanced electrochemical performance by alumina-coated graphite anodes via spray coating†

Abstract

Lithium-ion batteries (LIBs) are essential for energising portable devices, electric cars, and energy storage systems. Graphite is a frequently utilised anode material; nonetheless, the continual formation of a solid electrolyte interface (SEI) during cycling results in capacity degradation owing to electrolyte depletion. This study tackles this issue by employing alumina coatings on graphite electrodes via the spray coating technique, which is cost-effective and scalable. Electrodes with different alumina concentrations (1 wt%, 4 wt%, and 7 wt%) were assessed for electrochemical performance. The 1 wt% alumina-coated electrode demonstrated enhanced cycling stability, with 94.97% capacity retention after 100 cycles, in contrast to 91.74% for the uncoated graphite. The Al₂O₃ coating functions as a preformed SEI, diminishing electrolyte decomposition and improving the cycling performance and rate capability of electrodes, particularly at elevated C-rates. This research illustrates that using spray-coated alumina is an effective technique for enhancing the durability and performance of graphite anodes in lithium-ion batteries, with the potential for extensive applications in energy storage systems.