Engineering p-Band Center of Oxygen Boosting H + Intercalation in δ-MnO 2 for Aqueous Zinc Ion Batteries.

In aqueous zinc ion batteries (ZIBs), the H + intercalation possesses superior electrochemical kinetics with excellent rate capability, however, precisely modulating H + intercalation has been still challenging. Herein, a critical modification of pre-intercalating metal ions in the MnO 2 interlayer (M-MnO 2 ) with controllable p-band center (ϵ p ) of O is reported to modulate the H + intercalation. The modulation of metal-O bond type and covalency degree on the average charge of O atom results in optimized ϵ p and H + adsorption energy for M-MnO 2 , thus promoting the balance between H + adsorption and desorption, which plays a determinant role on H + intercalation. The optimized Cu-MnO 2 delivers superior rate capability with the capacity of 153 mAh g -1 at a high rate of 3 A g -1 after 1000 cycles. This work demonstrates that ϵ p could be a significant descriptor for H + intercalation, and tuning ϵ p effectively increases H + intercalation contribution with excellent rate capability in ZIBs.