Rational design of intertwined carbon nanotubes threaded porous CoP@carbon nanocubes as anode with superior lithium storage

Abstract

A novel 3D porous CoP@C-CNTs composite with CNTs threaded CoP@C nanocubes is rationally designed and demonstrated as a promising anode for lithium-ion battery. The CoP@C-CNTs composite displays high surface area and abundant pores resulted from the pyrolysis of metal-organic frameworks (MOFs). CoP nanoparticles are well encapsulated in MOFs-derived carbon nanocubes, which can effectively accommodate the volume change of active CoP during charge/discharge processes. Besides, the N/P co-doped feature induced in-situ in the synthesis process helps to improve the electrical conductivity. Moreover, the presence of intertwined CNTs network threaded CoP@C nanocubes is the vital part for rapid electron transportation within the whole electrode. As a result, the CoP@C-CNTs electrode exhibits a high initial discharge capacity of 1254 mAh g−1 at a current density of 0.1 A g−1, and an outstanding rate performance (532 mAh g−1 at current densities of 5 A g−1), as well as excellent cycling stability with a capacity fade rate of ∼0.02% per cycle over 500 cycles at the current density of 2 A g−1.