▎ 摘　　要

NOVELTY - Aqueous secondary lithium battery comprises anode, cathode, separator and mixed salt electrolyte. The cathode material of the cathode is binary niobium-based oxide composite material. The band gap width of MaObis more than 3.0 eV, which is used for improving the hydrogen evolution over potential at the interface of the cathode. The mixed-salt electrolyte comprises a mixed salt of aqueous lithium salt, alkali metal ion salt and/or large cationic organic salt. The molar ratio of the aqueous lithium salt to the total amount of the alkali metal ion salt and the large cationic organic salt is ≮1:10 in the mixed salt electrolyte. USE - The aqueous secondary lithium battery is used for power battery of electric vehicle, storage power station, the power grid energy storage, the portable electronic device and the aviation storage power supply (claimed). ADVANTAGE - The aqueous secondary lithium battery has improved hydrogen evolution over potential at the interface of the cathode, and stable work of the binary niobium-based oxide composite material with lower oxidation-reduction potential on the battery cathode. DETAILED DESCRIPTION - Aqueous secondary lithium battery comprises anode, cathode, separator and mixed salt electrolyte. The cathode material of the cathode is binary niobium-based oxide composite material (I). The general formula of the binary niobium-based oxide composite material is xMaOb.yNb2O5, where 1≤x≤9, 1≤y≤9, 1≤a≤3, 1≤b≤5 and M is magnesium, aluminum, phosphorus, titanium, vanadium, zinc, germanium, zirconium and hafnium. The band gap width of MaObmore than 3.0 eV is used to increase the hydrogen evolution over potential at the cathode interface. The mixed salt electrolyte comprises a mixed salt electrolyte composed of aqueous lithium salt, an alkali metal ion salt, and a large cationic organic salt In the mixed salt electrolyte. The molar ratio of the aqueous lithium salt to the total amount of the alkali metal ion salt and the large cationic organic salt is not less than 1:10. An INDEPENDENT CLAIM is also included for: a material for cathode aqueous secondary lithium battery; and a preparation method of the cathode material. DESCRIPTION OF DRAWING(S) - The drawing shows a structure schematic diagram of a novel aqueous secondary lithium battery. (Drawing includes non-English language text).