Interfacial Phonon Scattering Enables Ultrastable and High‐Power Sodium‐Based Dual‐Ion Batteries With Alloying Anodes

Abstract

ABSTRACT Alloying anodes offer a compelling route to high‐energy sodium‐based dual‐ion batteries (SDIBs), yet their repeated volume change accumulates destructive strain energy that rapidly degrades the electrode. Conventional interfacial designs often dissipate this energy through damage‐prone processes (e.g., cracking or delamination), which accelerates failure. Herein, we report a crystal‐plane friction interface (CPFI) strategy that enables a fundamentally different, low‐damage dissipation pathway. By embedding layered Na + ‐substituted α ‐zirconium phosphate (NZrP) nanoparticles into a polymer matrix, we construct a robust interface on Sn anode as a proof of concept. The accumulated strain energy is relieved through facile sliding between the NZrP (002) planes, which convert mechanical work into thermal phonons. In situ stress measurements confirm a 99.1% reduction in strain energy density, directly quantifying the efficacy of this mechanism. Meanwhile, Na + substitution in NZrP facilitates rapid Na + transport, achieving a substantial ∼65% reduction in interfacial impedance. Consequently, the Sn@CPFI anode enables SDIB full cells that retain over 80% capacity over 3500 cycles at 5C and deliver 90.1% capacity retention at 40C, significantly outperforming conventional counterparts. A practical pouch cell further validates this approach. This work establishes crystal‐plane sliding as a general mechanism for managing strain energy, opening a pathway to durable batteries with high‐volume‐change electrodes.