Fabricating 3D Network for FeP@MXene toward Stable and High-Capacity Lithium-Ion Storage.

Abstract

The designing and searching superior anode materials with low operation potential and rapid redox kinetics is of paramount importance. Incorporating transition metal (TM) into phosphorus to form TM phosphides and combining them with low-dimension materials represents effective strategy for enhancing the electrochemical performances. Herein, a 3D network FeP@MXene composite anode is proposed with exhibiting a high reversible capacity of 444.1 mAh g^-1 at current density of 500 mA g^-1 after 500 cycles for lithium-ion batteries. The study reveals that the exceptional cycling stability originates from the synergistic combination of high specific surface area and a structural design buffering volume expansion. Specifically, Prussian blue (PB) derived cubic structures are uniformly dispersed within a 3D interwoven network of MXene nanosheets. Notably, the pseudocapacitive dominated fast lithium storage kinetics of this active material induces uniformly incomplete lithium intercalation during the initial cycles. This mechanism effectively circumvents the severe capacity decay observed in conventional metal phosphides, which arises from heterogeneous lithium intercalation induced severe volume fluctuations. This work provides novel perspectives and insights for the rational design of high-performance metal phosphide anodes.