Preparation of SnO₂@graphite anode based on the oriented deposition methodology with superior electrode behavior for Li ion battery

SnO2-based anode materials are deemed to be one of the most prospective anode materials for Li ion batteries (LIBs) with higher theoretical capacity as compared to conventional graphite. However, the weak electrical conduction and large volume expansion limit its application in eVeryday life. Here, a simple and low-cost oriented deposition methodology is developed to prepare SnO2@graphite composite, which is obtained based on the redox reaction mechanism between SnSO4 and graphite. SnO2 nanoparticles are uniformly anchored on the carbon layer of graphite. The close anchoring of SnO2 in graphite effectively inhibits the volume expansion of SnO2 during lithiation/delithiation processes, and good combination state between them guarantees the excellent electrical conductivity of the composite. As anode for LIBs, SnO2@graphite electrode delivers superior reversible capacity and provides an improved rate capability compared to graphite electrode. Benefiting from the tight combination of SnO2 and graphite, the Li ion diffusion coefficient of SnO2@graphite electrode is almost twice that of graphite electrode. Pairing with LiFePO4 cathode, the SnO2@graphite/LiFePO4 full cell exhibits higher energy/power densities by comparison with graphite/LiFePO4. Besides, this advanced SnO2@graphite composite material with superior anode behavior can be mass produced by the reported methodology.