A Novel Tin‐Graphite Dual‐Ion Battery Based on Sodium‐Ion Electrolyte with High Energy Density

A novel Sn-graphite dual-ion battery (DIB) based on sodium-ion electrolyte is developed, using Sn foil as both anode and current collector. The Sn-G DIB presents a reversible capacity of 74 mA h g−1 at 2 C rate and keeps stable for 400 cycles with 94% retention, which also delivers a high energy density of 144 W h kg−1 at 150 W kg−1.