Patent ID: 8785050

Claim:
A lithium-ion secondary battery comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprising a negative electrode active material; and a non-aqueous liquid electrolyte, and wherein the negative electrode active material comprises as its primary component a graphitic material that satisfies each of the following properties: (a) in its Raman spectrum obtained by Raman scattering analysis using an exciting light at a wavelength of 532 nm, having a ratio of its D-peak intensity I D to its G-peak intensity I G , an R value (I D /I G ), of 0.15 or smaller; and (b) having a full width at half maximum of the G peak, Δv G , of 23 cm −1 or smaller; and the lithium-ion secondary battery shows a capacity retention rate of 70% or greater when subjected at to 500 cycles of charging and discharging at a constant current rate of 2 C at 60° C., and the positive electrode comprises an olivine lithium-containing compound.