SnO _x /graphene anode material with multiple oxidation states for high-performance Li-ion batteries

Tin and its oxides are promising anode materials owing to their high theoretical capacity, rich resource, and environmental benignity. To achieve low cost and green synthesis, a facile synthetic route of SnO _x /graphene composites is proposed, using a simple galvanic replacement method to quickly obtain abundant foamed tin as raw material and ball milling method to realize a mechanochemical reaction between SnO _x (0 ≤ x ≤ 2) and graphene. Under different annealing conditions, the foamed tin is converted to tin oxides with multiple oxidation states (Sn₃O₄, SnO, and SnO₂). These unique components can greatly affect the electrochemical performance of the electrode in LIBs. The as-prepared electrode (SnO _x -300/G) obtained by annealing foamed tin at 300 °C for 4 h and combining SnO _x powders with graphene via ball milling shows great cycling stability, retaining a high capacity of 786 mA h g^-1 at 0.1 A g^-1 after 150 cycles, and its initial Coulombic efficiency can reach 84.03%. Thus, this facile synthesis can provide an environmentally friendly route for commercial production of high-performance energy storage materials.