Approaching High-Performance Lithium Storage Materials by Constructing Hierarchical CoNiO2@CeO2 Nanosheets

In this work, the hierarchical CoNiO2@CeO2 nanosheet composites were successfully prepared by a one-step hydrothermal process with a subsequent annealing process for the first time. The CeO2 nanoparticles successfully deposit on the surface of CoNiO2 nanosheet, and benefit the improvement of electrical contact between CoNiO2 and CeO2. CeO2 modification improve the reversibility of insertion/extraction of Li-ions and electrochemical reaction activity, and promotes the transport of Li-ions. Benefited of the unique architecture and component, the CoNiO2@CeO2 nanosheet composites show high-reversible capacities, excellent cycling stability and good rate capability. The CoNiO2@CeO2 (5.0 wt%) shows a charge/discharge capacity of 867.1/843.2 mAh g(-1) after 600 cycles at 1 A g(-1), but the pristine CoNiO2 nanosheet only delivers a charge/discharge capacity of 516.9/517.6 mAh g(-1) after 500 cycles. The first-principles calculation reveals that valid interfaces between CeO2 and CoNiO2 can be formed, and the formation process of the interfaces is exothermic. The strong interfacial interaction resulting in an excellent structure stability and thus a cycling stability of the CoNiO2@CeO2 material. This work provides an effective strategy to develop high-performance anode materials for advanced a lithium-ion battery, and the CoNiO2@CeO2 nanosheet shows a sizeable potential as an anode material for next generation of high-energy Li-ion batteries.