Helmholtz Plane Regulation Empowers PF6− Permselectivity Towards High Coulombic Efficiency Dual Ion Battery of 5.5 V

de-solvation and simultaneously suppressing electrolyte oxidation decomposition. By virtue of such beneficial effects, the graphite cathode enables a 5.5 V DIB with a prominent capacity retention of 92 % and a high average Coulombic efficiency exceeding 99 % within 2000 cycles at 5 C, demonstrating significantly enhanced electrochemical reversibility. The Helmholtz plane regulation strategy marks a milestone in advancing DIB technologies.