Reinventing Phosphorus Anodes: Taming Pulverization via Strain-Induced Interfacial Coupling

Alloy-type anodes offer high theoretical capacity, yet their practical application is hindered by substantial volume expansion and particle pulverization. In this work, a proactive strategy is proposed to converts the inherent volume change from a detrimental issue into a driving force for interfacial stabilization. By leveraging the flexibility of robust single-walled carbon nanotubes (SWCNTs) and the large volume variation of phosphorus upon lithiation, the induced tensile strain in SWCNTs enhances their interaction with fragmented alloy particles, promoting interfacial coupling and the formation of P─C bonds. Operando Raman spectroscopy and density functional theory (DFT) calculations corroborate this chemomechanical coupling mechanism, which effectively stabilizes fractured phosphorus clusters, suppresses intermediate dissolution, and facilitates the reconstruction of a robust conductive network. As a result, the phosphorus anode incorporating only 1 wt% SWCNT delivers a high specific capacity of 1981.6 mAh g^-1 at 0.1C, 1235.6 mAh g^-1 at 5C, and maintains 1301.9 mAh g^-1 (78.1% retention) after 500 cycles at 1C. Moreover, the NCM811//BP─SWCNT full cell achieves 507 Wh kg^-1 and 1459.7 mAh g^-1 after 500 cycles at 1C. This study establishes an active stress-utilization design principle, providing new perspectives for developing high-energy-density alloy-type anodes.