▎ 摘　　要

NOVELTY - Cathode additive comprises composite material which is formed by inorganic lithium salt and conductive agent. The inorganic lithium salt is represented by linear formula. USE - Cathode additive. ADVANTAGE - The cathode additive improves discharge capacity, lithium battery energy density, cycle performance and multiplying power performance, and reduces charge transfer resistance. DETAILED DESCRIPTION - Cathode additive comprises composite material which is formed by inorganic lithium salt and conductive agent. The inorganic lithium salt is represented by LixMaNbOy, where x is 2-8, a is 0-1, b is 0-1, sum of a and b is more than or equal to 1, y is 2-6, M is selected from iron, cobalt, nickel, zirconium, vanadium, niobium, molybdenum, and N is aluminum, magnesium, titanium, chromium, ytterbium, silicone, tungsten, gallium, and zinc. INDEPENDENT CLAIMS are included for the following: (1) a method for preparing cathode additive, which involves adding lithium compound, M element-containing compound, N element-containing compound, dissolving in solvent and stirring to obtain uniform mixed solution, evaporating solvent, and drying to obtain precursor of inorganic lithium salt, calcining under protective gas atmosphere, cooling and ball milling to obtain inorganic lithium salt, dispersing particles of composite material ultrasonially inorganic lithium salt in solution which contains conductive agent and evaporating solvent and drying to obtain inorganic lithium salt formed with conductive agent to obtain cathode additive; (2) a cathode sheet, which comprises cathode current collector and cathode film which is disposed on cathode current collector, where cathode membrane further comprises cathode additive; and (3) a lithium battery, which comprises cathode sheet.