A metal-organic framework-derived engineering of carbon-encapsulated monodispersed CoP/Co2P@N-C electroactive nanoparticles toward highly efficient lithium storage

Attracted due to their potentially high theoretical capacities, storage redox activities, and diverse shape, cobalt phosphides (Co2P, CoP etc.) are thought to be the promising anodes for lithium-ion batteries (LIBs). Nevertheless, there still remain challenging bottlenecks of their low intrinsic conductivity and severe volume expansion when subjected to repeated electrochemical cycles, which unavoidably bring about structural collapse, active particle aggregation and rapid capacity degradation, and thereby poor long-term lifespan. Herein, we present a distinctively facile route and adopt metal-organic frameworks (MOFs) as the self-sacrificing hosts to construct carbon-encapsulated CoP/Co2P@N-C composites which are composed of monodispersed electroactive CoxP (CoP/Co2P) nanoparticles encapsulated in carbon nanotubes (CNTs) based on N-doped carbon substrates. Remarkably, one exemplary CoP/Co2P@N-C-600 electrode among them, when serves as anode for LIBs, exhibits high reversible capacity (977.9 mAh g-1, 100 cycles at 0.1 A g-1) and superior rate capability (639.7 mAh g-1 at 4 A g-1). Furthermore, an assembled LFP//CoP/Co2P@N-C-600 full cell displays remarkable cycling performance. The more advantageous synergistic interaction of distinctive carbon-encapsulated architectures, robust N-doped carbon frameworks and electroactive components provides the fundamental foundation for superior lithium storage capabilities, where the synergistic interaction contributes towards enhancing electronic conductivity, offering extra electrochemical active sites, shortening the Li+/e- transport channels and alleviating volumetric variation. This contribution emphasizes the value of rationally designing MOF-derived carbon encapsulated metal phosphide-based anodes for advanced LIBs.