Preparation method of doped layered lithium manganate

The invention relates to a preparation method of doped layered lithium manganate. The layered lithium manganate made by the method provided in the invention has a chemical formula shown as LiMn1-x(M)xO2-y(N)y. The making steps include: (1) making a precursor: mixing a manganese source, a cationic compound, and an anionic compound uniformly in a ratio of (0.95-1):(0-0.05):(0-0.02), then calcining the mixture at a high temperature of 500-900DEG C for 4-6h to generate a doped manganese oxygen compound, performing natural cooling, then taking it out, and conducting fully grinding again for 30min, thus obtaining the precursor; (2) mixing the lithium source with the precursor obtained in step (1) in a ratio of 1:(0.95-0.98), carrying out grinding for 30min, then adding sodium hydroxide or potassium hydroxide to further perform grinding for 10min, thus obtaining a mixture A; (3) dissolving the mixture A made in step (2) with ethanol absolute, adding the dissolved liquid into a high-pressure reaction kettle to let it