The electrosorption behavior of shuttle-like FeP: performance and mechanism.

Owing to its high electrochemical ability, the FeP is envisioned to be the potential electrode for capacitive deionization (CDI) with enhanced performance. However, it suffers from poor cycling stability due to the active redox reaction. In this work, a facile approach has been designed to prepare the mesoporous shuttle-like FeP using MIL-88 as the template. The porous shuttle-like structure not only alleviates the volume expansion of FeP during the desalination/salination process but also promotes ion diffusion dynamics by providing convenient ion diffusion channels. As a result, the FeP electrode has demonstrated a high desalting capacity of 79.09 mg g at 1.2 V. Further, it proves the superior capacitance retention, which maintained 84% of the initial capacity after the cycling. Based on post-characterization, a possible electrosorption mechanism of FeP has been proposed.