Selective Phosphorization Boosting High-Performance NiO/Ni(2)Co(4)P(3) Microspheres as Anode Materials for Lithium Ion Batteries

Phosphorization of metal oxides/hydoxides to promote electronic conductivity as a promising strategy has attracted enormous attention for improving the electrochemical properties of anode material in lithium ion batteries. For this article, selective phosphorization from NiCo(2)O(4) to NiO/Ni(2)Co(4)P(3) microspheres was realized as an efficient route to enhance the electrochemical lithium storage properties of bimetal Ni-Co based anode materials. The results show that varying phosphorizaed reagent amount can significantly affect the transformation of crystalline structure from NiCo(2)O(4) to intermediate NiO, hybrid NiO/Ni(2)Co(4)P(3), and, finally, to Ni(2)Co(4)P(3), during which alterated sphere morphology, shifted surface valance, and enhanced lithium-ion storage behavior are detected. The optimized phosphorization with 1:3 reagent mass ratio can maintain the spherical architecture, hold hybrid crystal structure, and improve the reversibly electrochemical lithium-ion storage properties. A specific capacity of 415 mAh g(−1) is achieved at 100 mA g(−1) specific current and maintains at 106 mAh g(−1) when the specific current increases to 5000 mA g(−1). Even after 200 cycles at 500 mA g(−1), the optimized electrode still delivers 224 mAh g(−1) of specific capacity, exhibiting desirable cycling stability. We believe that understanding of such selective phosphorization can further evoke a particular research enthusiasm for anode materials in lithium ion battery with high performances.