In situ formation of porous graphitic carbon wrapped MnO/Ni microsphere networks as binder-free anodes for high-performance lithium-ion batteries†
Flexible hybrid electrodes with high electronic conductivity and porosity have attracted great attention for energy storage and conversion systems. Herein, we report the fabrication of a porous graphitic carbon wrapped MnO/Ni microsphere network (MnO/Ni/CNF) by a combined solvothermal and electrospinning method followed by stabilization and carbonization processes. Carbon nanofibers which link porous MnO/Ni/C microspheres function as both a 3D conductive network and a current collector for the flexible composite electrode. Meanwhile, the porous MnO/Ni microspheres are coated with porous graphene-like carbon layers, further improving the electronic conductivity and facilitating the electrolyte penetration. When directly utilized as an anode material for LIBs, the MnO/Ni/CNF electrode exhibits excellent electrochemical performances, including high reversible capacity, good cycle stability and rate capability. The as-prepared flexible electrode delivers a capacity of 534.5 mA h g−1 at 200 mA g−1 after 100 cycles (based on the whole electrode mass) and possesses a capacity retention of 95.7% even after long-term 600 cycles at 1 A g−1, suggesting its promising applicability in lithium ion batteries as a flexible binder-free anode.