ELECTROLYTE MEDIUM FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY

To provide a lithium secondary battery that can suppress short circuits and has high energy density and high output.SOLUTION: An electrolyte medium for a lithium secondary battery contains a low dielectric constant solvent, a lithium salt, and a polyvalent cationic salt. The polyvalent cation salt is contained in the electrolyte medium in a dispersed state as particles and in a fluid state that is not solidified, and the high dielectric constant solvent content is 20% or less by mass. The lithium secondary battery provided with an electrolyte medium for a lithium secondary battery can suppress short-circuit and obtain high energy density and high power output.SELECTED DRAWING: Figure 8 【課題】短絡を抑制でき、高いエネルギー密度と高い出力を有するリチウム二次電池を提供すること。【解決手段】低誘電率溶媒と、リチウム塩と、多価カチオン塩と、を含有し、多価カチオン塩は電解質媒体中に粒子として分散した状態で、かつ、固体化されない流動状態で含有され、高誘電率溶媒の含有量が２０質量％以下である、リチウム二次電池用電解質媒体である。これらリチウム二次電池用電解質媒体を備えるリチウム二次電池によれば、短絡を抑制でき、高いエネルギー密度と高い出力が得られる。【選択図】図８