| abstract |
(57) [Summary] [PROBLEMS] By constructing an aqueous lithium secondary battery using a specific negative electrode active material, a lithium secondary battery with high safety, low cost, large capacity and good cycle characteristics is provided. The task is to provide. SOLUTION: A negative electrode including a lithium vanadium composite oxide as a negative electrode active material, a positive electrode including a positive electrode active material having a higher lithium storage / release potential than the lithium vanadium composite oxide, and an aqueous system in which a lithium salt is dissolved in water Comprising a lithium secondary battery comprising an electrolytic solution, the lithium-vanadium composite oxide has a specific crystal structure, That is, in the X-ray diffraction pattern by CuKα ray, 2θ = 13.9 ° ± 1 ° (θ is the diffraction angle) has the highest intensity peak, and the intensity of the peak is at least 5 times that of any other peak. Used. |