CoP/C composites synthesized by an in situ phosphorization method as high-performance anode materials for lithium-ion batteries

Abstract

Because of their great capacity to store lithium, cobalt-based phosphides are utilized as anode materials for lithium-ion batteries (LIBs). However, in practice, they are prone to capacity fading and volume expansion, which restrict their long-term use. Herein, a simple method was proposed to prepare CoP nanoparticles encapsulated in a Co-MOF-71 derived carbon layer (CoP/C). The carbon in the composites greatly improved the cycling stability and rate capability of CoP/C when compared with pure CoP. CoP/C exhibits a high initial discharge capacity of 823 mA h g⁻¹, a cycling durability of 338 mA h g⁻¹ over 100 cycles, a good initial coulombic efficiency of ca. 76%, and an excellent rate capability (1 A g⁻¹: 318 mA h g⁻¹ and 2 A g⁻¹: 284 mA h g⁻¹).