Facile fabrication of porous Ni(x)Co(3-x)O4 nanosheets with enhanced electrochemical performance as anode materials for Li-ion batteries.

Herein, we report a novel and facile route for the large-scale fabrication of 2D porous NixCo3-xO4 nanosheets, which involves the thermal decomposition of NixCo1-x hydroxide precursor at 450 °C in air for 2 h. The as-prepared 2D porous NixCo3-xO4 nanosheets exhibit an enhanced lithium storage capacity and excellent cycling stability (1330 mA h g(-1) at a current density of 100 mA g(-1) after 50 cycles). More importantly, it can render reversible capacity of 844 mA h g(-1), even at a high current density of 500 mA g(-1) after 200 cycles, indicating its potential applications for high power LIBs. Compared to pure Co3O4, the reduction of Co in NixCo3-xO4 is of more significance because of the high cost and toxicity of Co. The improved electrochemical performance is attributed to the 2D structure and large amounts of mesopores within the nanosheets, which can effectively improve structural stability, reduce the diffusion length for lithium ions and electrons, and buffer volume expansion during the Li(+) insertion/extraction processes.