A double-layer-coated graphite anode material for high-rate lithium-ion batteries

Graphite is currently the most widely used anode material for lithium-ion batteries. However, the rapid development of electric vehicle market puts forward higher requirements to the rate performance of graphite anode. Therefore, in this study, the double-layer-coated (hard carbon and alumina coated) artificial graphite particles (AG@HC@Al2O3) are obtained to meet the requirements above. The inner hard carbon layer improves the rate performance with its large layer spacing. For the outermost ceramic layer of alumina, it further improves the high current charging capacity by improving the wettability of electrolyte to graphite anode. On the other hand, it acts as artificial solid electrolyte interphase film to slow down the loss of coulomb efficiency caused by hard carbon coating. The AG@HC@Al2O3 presents an excellent capacity retention rate of 94.4% at the rate of 1C (1C = 372 mAh g−1) after 150 cycles.