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

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.