Binder‐induced ultrafast PF 6 − ‐intercalation toward a high‐voltage, high‐power and long‐cycling zinc–graphite dual‐ion battery

Abstract Metallic zinc is an ideal anode material owing to its high theoretical capacity (819 mAh·g −1 ), eco‐friendliness, low cost and high safety, which have driven fast development of Zn‐ion batteries (ZIBs). However, the practical application of current ZIBs is significantly restricted by irregular dendrite growth of zinc anode and the low working voltage (usually < 2 V) of cathode materials. Herein, we report a high‐voltage Zn‐based dual‐ion battery (DIB), which is constructed by a graphite cathode, a Zn anode, and 3 M LiPF 6 in the ethyl methyl carbonate (EMC) electrolyte. Under the corrosion interaction of Li + ions, Zn 2+ can be easily dissolved from Zn anode into the electrolyte to enable dendrite‐free Zn 2+ plating/stripping at the anode. Moreover, an aqueous carboxymethyl cellulose (CMC) binder is employed to generate a robust cathode electrolyte interface (CEI) layer on the graphite cathode, which renders ultrafast PF 6 − ‐de‐/intercalation into graphite. The resultant Zn–graphite DIB operates stably at a high cut off voltage of 3.2 V, corresponding to an average output voltage of 2.2 V. After 9000 cycles at 5 C, the high capacity retention of 95.9% can be achieved with ~ 100% Coulomb efficiency. Based on the mass of cathode material, our Zn–graphite battery exhibits ultrafast rate capability (60 C, a discharge time of 44 s) and high energy/power densities (208 Wh·kg −1 at 214 W·kg −1 ; 142 Wh·kg −1 at 8692 W·kg −1 ), which holds great promise for large‐scale energy storage.