A Superior δ-MnO 2 Cathode and a Self-Healing Zn-δ-MnO 2 Battery

While α-MnO2 has been intensively studied for zinc batteries, δ-MnO2 is usually believed to be more suitable for ion storage with its layered structure. Unfortunately, the extraordinary Zn ion storage performance that δ-MnO2 should exhibit has not yet been achieved due to the frustrating structural degradation during charge–discharge cycles. Here, we found the Na ion and water molecules pre-intercalation can effectively activate stable Zn ion storage of δ-MnO2. Our results reveal that the resulted Zn//pre-intercalated δ-MnO2 battery delivers an extraordinarily high-rate performance, with a high capacity of 278 mAh g–1 at 1 C and up to 20 C, and a high capacity of 106 mAh g–1 can still be measured. The capacity…

• NN
  National Natural Science Foundation of China

  Award: 21771127
• RG
  Research Grants Council, University Grants Committee

  Award: CityU 11305218