A Single‐Layer Piezoelectric Composite Separator for Durable Operation of Li Metal Anode at High Rates

Piezoelectric ceramic and polymeric separators have been proposed to effectively regulate Li deposition suppress dendrite growth, but such still fail satisfactorily support durable operation of lithium metal batteries owing the fragile layer or low‐piezoelectricity polymer as employed. Herein, by combining PVDF‐HFP ferroelectric BaTiO 3 , we develop a homogeneous, single‐layer composite separator with strong piezoelectric effects inhibit growth while maintaining high mechanical strength. As squeezed local protrusion, polarized PVDF‐HFP/BaTiO generates voltage local‐intensified electric field further deconcentrate regional lithium‐ion flux retard on hence enabling smoother more compact morphology than unpoled pure separator, especially at rates. Remarkably, homogeneous incorporation highly improves performances residual polarization 0.086 μC cm −2 after treatment, four times that simultaneously increases transference number from 0.45 0.57. Beneficial prominent mechanism, enables stable cyclic Li¦¦LiFePO 4 cells for 400 cycles 2 C (1 = 170 mA g −1 ) capacity retention above 99%, 600 5 over 85%.