The local disorder induced by high-entropy doping results in highly stable cathode materials for aqueous potassium-ion batteries

Aqueous potassium-ion batteries are poised to become leading candidates for next-generation large-scale storage technology due to their low cost and safety features. However, the stability of aqueous potassium-ion battery materials faces significant challenges. The large ionic radius of potassium ions causes significant stress changes in the ordered crystal structure of the materials during the charge-discharge process. To address this issue, we synthesized high-entropy-doped layered manganese oxide (HE-KMO). High-entropy doping reconstructed the electron cloud distribution between the layers of HE-KMO, causing local disorder in HE-KMO. Local disorder reduces the transport barrier by inducing the transport of potassium ions and alleviates the stress on the material. It prevented phase transitions of HE-KMO during charging and discharging, improving the stability of HE-KMO. We used HE-KMO in the cathode material of aqueous potassium-ion batteries. Under a current of 5 A g−1, HE-KMO maintains an outstanding capacity retention after 5000 cycles. [Display omitted] •Highly stable charge/discharge cycling of aqueous potassium ion battery materials is achieved by local disorder.•High entropy doping reduces the transport energy barrier of potassium ions.•The local disorder reduces the stress suffered by the material during the charging and discharging process.