Synthesis of LiFePO₄/graphene microspheres while avoiding restacking of graphene sheet's for high-rate lithium-ion batteries

LiFePO₄/graphene microspheres are synthesized while avoiding the restacking of graphene sheets using a spray-drying process and a subsequent heat treatment. To determine an optimal condition for preventing the restacking of graphene sheets in the composites, we control the weight ratio of LiFePO₄ to rGO. When the amount of rGO in the composite exceeds a specific amount, the rGO sheets are spontaneously restacked. The restacked rGO sheets impede the Li ion movement, which is leading to the deterioration of the electrochemical performance at high C-rates. The microspheres synthesized exhibit a high specific capacity, excellent rate capability, and good cycling stability.