Active Control of Interface Dynamics in NASICON-Based Rechargeable Solid-State Sodium Batteries

Severe challenges are restraining the practical application of solid-state batteries, such as the dendrite growth and unsatisfactory compatibility between solid electrolyte and electrode. Here, we propose an interface dynamic control (IDC) strategy to ensure the stable operation of NASICON-based solid-state sodium batteries. First, we introduce intergranular phase (CuO) to effectively promote the densification of Na₃Zr₂Si₂PO₁₂ with an optimized ionic conductivity of 1.74 × 10⁻³ S cm⁻¹ at 25 °C. Moreover, the kinetically formed Na-Cu-O interlayer reveals outstanding conductive capability. The dramatically reduced interfacial area-specific resistance (70 ohm cm⁻²) boosts the resistance to Na dendrite growth, ensuring the excellent cycling stability of symmetric Na cells at a current density of 0.4 mA cm⁻² and room temperature. All-solid-state sodium metal batteries with Na₃V1.5Cr0.5(PO₄)₃ cathode and modified Na₃Zr₂Si₂PO₁₂ ceramic electrolyte reveal a high retention of 87.4% at 100 mA g⁻¹ over 300 cycles. This work opens up a new route for the rational interface design of NASICON-structure solid electrolyte toward the application in the high energy-density and high safety electrochemical energy storage devices.