Earth-Rich Transition Metal Phosphide for Energy Conversion and Storage

Low‐cost and resourceful transition metal phosphides (TMPs) have gradually received wide acceptance in the energy industry through exhibiting comparable catalytic activity and long‐term stability to traditional catalysts (e.g., Pt/C, LiCoO2, LiFePO4, etc.). With the emergence of the research hotspot of TMPs, probing their mechanism of catalytic energy conversion and storage inspired by the superb structure of metal‐phosphorus chelate is of great significance. To this end, recent developments in TMPs with various crystal structures and morphologies have attracted much attention. The design of TMPs ranging from the choice of different transition metals to phosphorus sources has been intensively explored. This research has indicated that multidimensional morphologies of TMPs prominently enrich the patterns of charge storage and electron transportation, and ultra‐nanoscaled TMPs obtained by multiple tools and techniques might challenge the threshold of electrocatalytic reactions. Here, recent developments in synthetic strategies of TMPs from different precursors are classified. The underlying mechanism between the structural and crystallographic characteristics and the tuned properties of TMPs in energy applications is also presented. Additionally, the key trends in structure and morphology characterization of TMPs are highlighted. Future perspectives on the challenges and opportunities facing TMPs catalysts are thereby proposed. Recent work toward exploring high‐performance TMPs applied in energy conversion and storage is summarized. For each class of TMPs, advances in synthetic mechanisms and methods to the key trends in structure and morphology characterizations in full‐scale energy applications are discussed. Lastly, perspectives on challenges and opportunities facing TMPs are presented to shed light on their promising future.