Nanoflake δ-MnO2 deposited on carbon nanotubes-graphene-Ni foam scaffolds as self-standing three-dimensional porous anodes for high-rate-performance lithium-ion batteries

The electrification of transportation necessitates the growth of high-power-density lithium ion batteries. However, traditional graphite anodes in lithium ion batteries perform poorly especially when charged or discharged under high current density. In this work, we deposit nanoflake δ-MnO2 on the carbon nanotubes-Graphene-Nickel foam compound matrix and apply it as a self-standing anode without binder or conductive agent. This composite buffers volume change, enables more electrochemical active sites, boosts the conductivity of electrode materials and facilitates lithium-ion diffusion. The resulting lithium ion batteries with the composite anodes show improved cycle life and enhanced rate performance, yielding a high specific capacity of 1250 mAh g−1 for 350 cycles at 0.4 A g−1 and 490 mAh g−1 over 700 cycles at 4.0 A g−1.