One-Step Binding and Wrapping Fragmented Natural Microcrystalline Graphite via Phenolic Resin into Secondary Particles for High-Performance Lithium-Ion Battery Anode

Research on graphite as anode material for lithium-ion batteries (LIBs) has been carried out for a long time. Natural microcrystalline graphite (MG) with low cost and eco-friendly properties is a promising anode for LIBs. However, the tiny and irregular MG would cause serious side reactions with electrolytes and reduce the efficiency of energy storage. Here, the alkali fusion acid leaching method is employed for the purification of MG. After removing impurities, the purified MG is bound and wrapped by phenolic resin pyrolytic carbon to form secondary particles (PCG). Benefiting from the formation of secondary particles with a carbon shell, PCG exhibits a high specific capacity of 354.3 mAh/g and outstanding rate performance (82.7% capacity retention at 2 C). Meanwhile, outstanding cycling stability is demonstrated, with 92.7% capacity retention after 500 loops at 2 C. This research cleverly employs phenolic resin pyrolytic carbon to bind and wrap fragmented MG into secondary particles by a one-step method for high-performance LIBs anode. Such a “one stone two birds” strategy is cost-effective, environmentally friendly, and simple to operate, which is highly valuable for practical applications and provides a reference for the optimization of other graphite materials.