Preparation of shape-controlled electric-eel-inspired SnO 2 @C anode materials via SnC 2 O 4 precursor approach for energy storage

A tin dioxide/carbon composite (SnO 2 @C) with controlled shape is fabricated using a two-step method, which includes preparation of SnC 2 O 4 precursors and subsequent heat treatment process. SnC 2 O 4 precursors with different morphologies are synthesized by controlling the different proportions of tin sources, and some characterization techniques are carried out to screen out the optimum precursors. And the precursors are further annealed to obtain nanostructured SnO 2 and coated with carbon film. Ultimately, shape-controlled SnO 2 @C anode materials are prepared, and the reaction process and electrochemical properties of SnO 2 @C composites as anode materials are further studied. The SnO 2 @C composite shows the capacity of 659.4 mAh g −1 after 100 cycles at a current density of 100 mA g −1 . Even at the rate of 2000 mA g −1 , the composite electrode can maintain a reversible capacity of 507.2 mAh g −1 . The excellent electrochemical performance is beneficial to the synergistic effect between the carbon coating film and the nanostructured SnO 2 , which provides sufficient lithium storage sites, good electronic conductivity and void space to relieve the volume expansion.