NOVELTY - Use of lithium-containing sulfone compound (I) as additive in high-voltage non-aqueous electrolyte, is claimed.    USE - Lithium-containing sulfone compound for use as additive in high-voltage non-aqueous electrolyte for preparing secondary battery (all claimed) such as lithium ion battery that is utilized in mobile phone, portable computer, camera, other livelihood and automotive vehicle power supply.    ADVANTAGE - The lithium-containing sulfone compound (I) provides the battery with better charging cut-off voltage, high operating voltage platform, a high energy density, a low cycle capacity fade, a high charging/discharging coulomb efficiency, better stability, improved performance in withstanding high temperatures, and a wide application range.    DETAILED DESCRIPTION - Use of lithium-containing sulfone compound of formula (I) as high-voltage non-aqueous electrolyte additive, is claimed.    R1 = F, 1-8C alkyl, 1-8C fluoroalkyl or 1-8C fluoroalkoxy; and    R2 = 1-8C fluoroalkyl or 1-8C fluoroalkoxy.    INDEPENDENT CLAIMS are also included for the following:    (1) a high-voltage non-aqueous electrolyte comprising lithium salt, where the lithium salt dissolved in a non-aqueous solvent and an additive, the additive is lithium-containing sulfone compound (I), and the concentration of the additive is 0.05-10 mass%    (2) a high voltage non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode and a high voltage non-aqueous electrolytic solution, where the positive electrode comprises positive electrode active material having capability of deintercalating lithium ions reversibly, the negative electrode having a negative electrode active material having capability of reversibly deintercalating lithium ions    (3) a method for preparing a high voltage non-aqueous electrolyte secondary battery, which involves utilizing a positive electrode active material and negative electrode active materials to prepare positive and negative electrodes, dissolving the lithium salt containing lithium-containing sulfone compound (I) in a non-aqueous solvent, to prepare a non-aqueous electrolytic solution, assembling the positive electrode, negative electrode and non-aqueous electrolyte solution into a high voltage nonaqueous electrolyte secondary battery.