The invention discloses a preparation method and application of a
sodium ion battery positive
electrode material. The method comprises the following steps: dissolving at least five
metal element salts, a chelating agent and water to obtain a solution A; dissolving
sodium ferrocyanide in deionized water to obtain a solution B; and slowly adding the solution A into the solution B at
room temperature in an atmospheric environment, carrying out a co-
precipitation reaction, and sequentially aging, centrifuging, washing and
drying the obtained product to obtain the
sodium-deficient
prussian blue analogue containing
crystal water, putting the sodium-deficient
prussian blue analogue containing
crystal water into an
iodide solution for
ultrasonic dispersion, and carrying out directional oxidation-reduction reaction; and after the reaction, sequentially centrifuging, washing and
drying to obtain a high-entropy
Prussian blue analogue which is rich in
alkali metal ions and does not contain
crystal water, namely the
sodium ion battery positive
electrode material. When the positive
electrode material is applied to the sodium-
ion battery, the positive
electrode material is de-intercalated together in the circulation process, the working
voltage of the sodium-
ion battery is improved by 0.16 V, and the high
specific energy density of the battery can be realized.