Abstract: An electrode active material includes a layered metal oxide. The layered metal oxide has the following general formula: NaxM1aM2bMn1-a-bO2-zFz; where 0.55?x?0.85, a?0, b?0, 0.1?a+b?0.33, and 0.06?z/(1?a?b)?0.13; M1 is selected from one or more of alkali metal elements other than Na and alkaline earth metal elements; and M2 is selected from one or more of transition metal elements other than Mn.

Abstract: An electrode active material is provided. The electrode active material includes a layered metal oxide having a general formula NaxZnaNibMncM1dO2M2e, where 0.6?x?0.85, 0.95?a+b+c+d?1.05, 0?d?0.05, and 0?e?0.067, and where 0.04?a/c?0.1 and 0.23?b/c?0.45. M1 is selected from at least one of alkaline earth metal elements, transition metal elements, and alkali metal elements other than Zn, Ni, and Mn, and M2 is selected from non-metallic elements other than O.

Abstract: Provided are a positive active material for use in a sodium-ion battery, a method for preparing same, a positive electrode plate containing same, a sodium-ion battery, and an electrical device. The method for preparing a positive active material for use in a sodium-ion battery includes the following steps: mixing a positive active material for use in a sodium-ion battery with, and causing the positive active material to react with, a washing solution at a temperature of T1, and filtering and drying a product of the reaction to obtain a washed positive active material for use in a sodium-ion battery, where the washing solution is deionized water or an acidic solution with a pH value lower than 7.0, and 0° C.?T1<20° C.