Engineering novel Ni2-XCoxP structures for high performance lithium-ion storage

Abstract

Doping methods of Ni2-xCoxP are widely used to control the structural parameters and optimize the material performance, yet using the controllable amount of doping as a synthesis method to that is still relatively scarce. Here, we report a novel self-induction and self-assembly method to control the level of Co-doping Ni2P and hence deliver the ability to tune the morphological structure, resulting in the three-dimensional (3D) Ni2-xCoxP (0≤x≤1.2) flower-like electrode materials. The redistribution of electrons, optimization of binding energy, and defect engineering caused by the Co-doping, have been proven to improve the electronic conductivity, ion transport capacity and electrochemical activity of the Ni2-xCoxP electrode materials. From the perspective of the microstructure, the controllable regulation of the micro and/or nano-structure morphology promoting cycle stability and reversibility. In this work, Ni1.2Co0.8P has been identified as the best anode material among the Ni2-xCoxP(0≤x≤1.2) family, exhibiting ultra-high reversible specific capacity (808mAh g−1 at 0.1A g−1 after 400 cycles), excellent rate performance, and cycle stability, Moreover, its application to lithium-ion capacitors also shows a high energy and power density, demonstrating that Ni2-xCoxP is a promising candidate for practical energy storage applications.