Hierarchical Ni(HCO3)2 Nanosheets Anchored on Carbon Nanofibers as Binder-Free Anodes for Lithium-Ion Batteries

Transition metal carbonates are promising anodes for energy storage and conversion due to their advantages of facile synthesis, large theoretical capacities, and high electrochemical activities. However, the poor electronic conductivity, slow ion transport, and high volume expansion lead to the capacity loss of transition metal carbonates. Herein, hierarchical Ni(HCO3)(2) nanosheets are directly grown on carbon nanofibers (CNFs) via electrospinning and hydrothermal methods. The 3D CNFs can not only improve the electronic conductivity and shorten diffusion length but also fasten electron/ionic transport and release the volume change. Ni(HCO3)(2) nanosheets anchored on CNFs exhibit excellent lithium storage performance with a high cycling stability and good rate capability. It delivers an initial discharge capacity of 3807.6 mAh g(-1) and a reversible capacity of 1261.1 mAh g(-1) after 100 cycles at 200 mA g(-1). This work may shed light on the preparation of other binder-free transition metal carbonates and make them as high-performance electrodes in flexible electronic devices.