Electrophoretic Deposition of Binder‐Free MnO 2 /Graphene Films for Lithium‐Ion Batteries

Binder‐free, nano‐sized needlelike MnO 2 ‐submillimeter‐sized reduced graphene oxide ( nMnO 2 ‐srGO ) hybrid films with abundant porous structures were fabricated through electrophoretic deposition and subsequent thermal annealing at 500 °C for 2 h. The as‐prepared hybrid films exhibit a unique hierarchical morphology, in which nMnO 2 with a diameter of 20—50 nm and a length of 300—500 nm is randomly anchored on both sides of srGO . When evaluated as binder‐free anodes for lithium‐ion half‐cell, the nMnO 2 ‐srGO composites with a content of 76.9 wt% MnO 2 deliver a high capacity of approximately 1652.2 mA •h•g −1 at a current density of 0.1 A•g −1 after 200 cycles. The high capacity remains at 616.8 mA •h•g −1 ( ca. 65.1% capacity retention) at a current density as high as 4 A•g −1 . The excellent electrochemical performance indicates that the nMnO 2 ‐srGO hybrid films could be a promising anode material for lithium ion batteries ( LIBs ).