Spatial Confinement Induced by Bimetallic Phosphides Heterostructure Toward Stable Sodium Storage Materials

作者：Deliang Cheng, Kun Zhang, Leyi Ye, Lintong Li, Qiang Huang, Longbin Li, Han Zhou, Shicheng Yu, Rüdiger‐A. Eichel, Peter H. L. Notten, Yiwang Chen · 发表于：Advanced Energy Materials · 年份：2025 · DOI：10.1002/aenm.202504025 · 被引用次数：4 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、MXene and MAX Phase Materials

Abstract Tin phosphide (Sn 4 P 3 ) has emerged as a promising anode material for sodium‐ion batteries (SIBs) owing to its high theoretical capacity and favorable redox potential. However, unstable Sn 0 intermediates and Sn 0 /Na 3 P interfaces formed upon (de)sodiation severely compromise its reversibility and stability. Herein, heterostructure configurations of Sn 4 P 3 /MP x (M = Mn, Fe, Cu, etc.) enclosed inside conductive graphene sheets (G) have been proposed and fabricated. The in situ formed M 0 intermediates during sodiation exhibit strong adsorption energies on Sn 0 , which offer enhanced spatial confinement to mitigate particle agglomeration and volumetric expansion of Sn 0 . The bimetallic phosphide heterostructures further promote charge transfer and ion diffusion kinetics by establishing built‐in electric fields and optimized Na + migration pathways. As a result, Sn 4 P 3 /MP x @G anodes exhibit superb sodium storage performance. Especially, the optimized Sn 4 P 3 /CuP 2 @G can deliver a high initial Coulombic efficiency of 90.9%, high cyclic Coulombic efficiencies (>99.5%), and ultralong cycleability (3500 cycles with 429.5 mAh g −1 at 1 A g −1 ). When paired with a Na 3 V 2 (PO 4 ) 3 cathode, the full cell combines a high energy density of 213.6 Wh kg −1 and an excellent capacity retention of 98% after 500 cycles. This work elucidates the (de)sodiation mechanisms of bimetallic phosphides and offers new insights into the development of advanced SIBs.