Synergy effect: The porous carbon nanobox encapsulated monodisperse CoP (CoP@PCB) was developed via a low-temperature phosphorization strategy. Compared to bare CoP electrodes, CoP@PCB electrodes have demonstrated excellent reversible capacity (820 mAh g−1 after 200 cycles at 0.2 A g−1) and superior rate capability (up to 5 A g−1), all of which are attributed to the design of their hollow carbon nanoboxes.
Transition metal phosphides (TMPs) are perplexed by the low electronic/ionic conductivity, volume variations, and unstable reaction interfaces. To tackle these issues, herein, we have proposed a low-temperature phosphorization strategy by reactions between Co-based metal-organic frameworks (MOF) and sodium dihydric hypophosphite to encapsulate monodisperse CoP nanoparticle (∼12 nm) into MOF-derived hollow and porous carbon nanobox (CoP@PCB). Compared to bare CoP, such CoP@PCB electrode has shown remarkable electrochemical performance, which is highly ascribed to its robust structural feature, pre-reserved voids, monodisperse CoP nanoparticles, and stable reaction interfaces, as well as fast reaction kinetics. Moreover, the good electrochemical properties of CoP@PCB//LiFePO4 full cells have demonstrated practical possibility. The formation of Co and Li3P as discharged products has corroborated the redox conversion reaction mechanism, as assessed by in-situ X-ray diffractions. The favorable function of the carbon shell in boosting both electronic conductivity and lowering diffusion energy barriers has been confirmed by theoretical calculations, demonstrating an important synergistic effect.Zum Volltext