Abstract: A nonaqueous electrolyte secondary battery includes an electrode assembly and an electrolyte solution. The electrode assembly is impregnated with at least part of the electrolyte solution. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The separator separates the positive electrode and the negative electrode from each other. The negative electrode includes a negative electrode active material. The negative electrode active material includes graphite. The following relation of a formula (1) is satisfied: “1.60?NPR/AAR?2.55”. “NPR” represents a ratio of a negative electrode charging capacity to a positive electrode charging capacity. “AAR” represents a ratio of an effective discharging capacity of the negative electrode to a total of a capacity corresponding to an amount of inactive lithium adhered to the negative electrode and the effective discharging capacity of the negative electrode.

Abstract: Provided is a non-aqueous electrolyte secondary battery having excellent properties even at low temperatures. The non-aqueous electrolyte secondary battery comprises: an electrode assembly including a positive electrode plate and a negative electrode plate; a non-aqueous electrolyte; an exterior body having an opening, and accommodating the electrode assembly and the non-aqueous electrolyte; and a sealing plate for sealing the opening of the exterior body, wherein the negative electrode plate has a negative electrode core and a negative electrode active material layer formed on the negative electrode core, and the non-aqueous electrolyte contains a non-aqueous solvent, the non-aqueous solvent containing 50-80 vol % of a chain carbonate with respect to the non-aqueous solvent, and containing, as the chain carbonate, 30-40 vol % of dimethyl carbonate, 3-8 vol % of propylene carbonate, and 2-5 vol % of methyl propionate with respect to the non-aqueous solvent.

Abstract: A nonaqueous electrolyte secondary battery includes an electrode assembly and an electrolyte solution. The electrode assembly is impregnated with at least part of the electrolyte solution. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The separator separates the positive electrode and the negative electrode from each other. The negative electrode includes a negative electrode active material. The negative electrode active material includes graphite. The following relation of a formula (1) is satisfied: “1.60?NPR/AAR?2.55”. “NPR” represents a ratio of a negative electrode charging capacity to a positive electrode charging capacity. “AAR” represents a ratio of an effective discharging capacity of the negative electrode to a total of a capacity corresponding to an amount of inactive lithium adhered to the negative electrode and the effective discharging capacity of the negative electrode.

Abstract: A nonaqueous electrolyte secondary battery includes an electrode assembly including a negative electrode and a positive electrode including a positive electrode active material mix layer containing a lithium-transition metal composite oxide which is a positive electrode active material; a nonaqueous electrolyte; and a battery case that houses the electrode assembly and the nonaqueous electrolyte. The positive electrode active material has a film formed thereon and the film contains 0.04 ?mol to 0.19 ?mol of sulfur per square meter of the specific surface area of particles of the positive electrode active material.