A B-doped layered VOPO4·2H2O cathode for high-performance zinc-ion batteries with an H+/Zn2+ co-insertion mechanism

B-doping engineering provides a strategy to increase the content of V 4+ in VOPO 4 ·2H 2 O and improve its H + /Zn 2+ co-intercalation capacitance as a cathode for zinc-ion batteries.