Tailoring and understanding the lithium storage performance of triple-doped cobalt phosphide composites.

CoP and N, O, P triple-doped carbon composites were prepared by low-temperature tandem reaction using MOF as a self-sacrificial template, and their lithium storage properties and mechanisms were investigated. [Display omitted] • The formation of dispersed cubic structure facilitates electrolyte penetration and Li+ diffusion. • Heteroatoms doping adjusts the local electric field of the anode improving the reactivity of the material. • Transformation of the mechanism of CoP anode before and after cycling was confirmed by ex-situ techniques. • Theoretical calculations demonstrate the synergistic effect between the co-doped carbon layer and CoP. Cobalt phosphide (CoP) with high theoretical capacity as well as ceramic-like and metal-like properties is considered as a promising anode for lithium-ion batteries (LIBs). However, the large volume change and sluggish kinetic response limit its practical application. The optimization of composition, structural control and performance regulation of CoP electrodes can be achieved by the bottom-up assembly technique of metal–organic frameworks (MOFs). Due to the effective electronic regulation and lithiophilicity brought by the multiple heteroatoms doping and the synergistic effect of the unique structure derived from MOFs, the N, O, P triple-doped carbon and CoP composites (ZCP@NOP) exhibited excellent rate capability (554.61 mAh g−1 at 2 A g−1) and cycling stability (806.7 mAh g−1 after 500 cycles at 0.5 A g−1). The essence and evolution of lithium storage mechanism in CoP electrodes are also confirmed by the ex-situ techniques. The synergistic benefits of heteroatom co-doping carbon and cobalt phosphide, such as the decrease of the diffusion energy barrier of Li-ions and the optimization of electronic structures, are highlighted in theoretical calculations. In conclusion, new thoughts and ideas for the creation of future battery anode are provided by the combination of the N, O, P co-doping and the adaptable structural adjustment technique. [ABSTRACT FROM AUTHOR]