Co pre-intercalated Layered K0.27MnO2·0.54H2O as high capacity cathode for aqueous zinc ion batteries

Aqueous zinc ion batteries (ZIBs) have attracted many scholars' attention due to its environmental benignity and high safety. Manganese dioxide , as one of the cathode materials of high-performance ZIBs , has high theoretical capacity and safety. However, due to the disproportionation reaction of Mn 3+ , the structure collapse caused by the dissolution of Mn 2+ has become the main problem of manganese-based materials. We dope Co 2+ into K 0.27 MnO 2 ⋅0.54H 2 O (Co-KMnO). The doped Co introduces more crystal water, which supports the layered structure of materials and makes it have excellent long cycle performance. It can reach a specific capacity of 192.5 mAh g −1 at 1 ​A ​g −1 and good stability with 158.3 mAh g −1 even after 800 cycles.