Abstract: A lithium-ion battery with high safety is provided. A lithium-ion battery 20 includes an electrode group 6, an electrolyte, and a battery container 5 that contains the electrode group 6 and the electrolyte. The electrode group 6 is formed by stacking a positive electrode and a negative electrode via a separator. The positive electrode contains a composite oxide of lithium, nickel, manganese, and cobalt as a main positive active material. The negative electrode contains amorphous carbon as a main negative active material. The lithium-ion battery 20 has a discharge capacity of 20 Ah or more. The ratio (the value of Y/X) of a volume Y occupied by the electrolyte to a volume X of a void space in the battery container 5 is 0.65 or more.

Abstract: A lithium-ion battery with high safety is provided. A lithium-ion battery 20 includes an electrode group 6, an electrolyte, and a battery container 5 that contains the electrode group 6 and the electrolyte. The electrode group 6 is formed by stacking a positive electrode and a negative electrode via a separator. The positive electrode contains a composite oxide of lithium, nickel, manganese, and cobalt as a main positive active material. The negative electrode contains amorphous carbon as a main negative active material. The lithium-ion battery 20 has a discharge capacity of 20 Ah or more. The ratio (the value of Y/X) of a volume Y occupied by the electrolyte to a volume X of a void space in the battery container 5 is 0.65 or more.

Abstract: A high-input and high-output battery having a large capacity while guaranteeing safety is provided. As a composition of an electrolytic solution, a composition ratio of ethylene carbonate (EC) is 20 vol % or more and 30 vol % or less, and a composition ratio of dimethyl carbonate (DMC) is 36 vol % or more and 50 vol % or less, and a composition ratio ? (DMC/EMC) of dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) is 1.0???1.7. Furthermore, a composition ratio of an additive is 0.1 wt. % or more and 1.0 wt. % or less, and a concentration of lithium salt is 1.0 mol/L or more and 1.5 mol/L or less.

Abstract: The present invention provides a cylindrical lithium-ion secondary battery. The lithium-ion battery of the present invention has a structure in which the value of B/A is optimized, where the distance between an electrode pole to which strip-form lead pieces are welded, the lead pieces being formed intermittently in the winding direction, which is the longitudinal direction of the belt-like electrodes, and the inner wall of the battery can is represented by A, and the distance between the electrode pole and the wound electrode group is represented by B, in order to secure an exhaust passage for the gas generated upon occurrence of an abnormality in the battery.

Abstract: A high-input and high-output battery having a large capacity while guaranteeing safety is provided. As a composition of an electrolytic solution, a composition ratio of ethylene carbonate (EC) is 20 vol % or more and 30 vol % or less, and a composition ratio of dimethyl carbonate (DMC) is 36 vol % or more and 50 vol % or less, and a composition ratio ? (DMC/EMC) of dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) is 1.05???1.7. Furthermore, a composition ratio of an additive is 0.1 wt. % or more and 1.0 wt. % or less, and a concentration of lithium salt is 1.0 mol/L or more and 1.5 mol/L or less.

Abstract: Provided herein is a nonaqueous electrolyte battery separator capable of rendering a battery flame-retardant and suppressing a reduction in battery performance is provided. A porous front-side protective layer 47 is formed on a front surface 45A of a porous base material 45 made of a polyolefin-based resin. The front-side protective layer 47 protects the porous base material 45 such that the porous base material 45 is not thermally deformed or thermally contracted. A porous front-side flame retardant layer 49 is formed on the front-side protective layer 47. The front-side flame retardant layer 49 contains solid flame retardant having a melting point lower than the ignition temperature of a nonaqueous electrolyte.

Abstract: The present invention provides a cylindrical lithium-ion secondary battery. The lithium-ion battery of the present invention has a structure in which the value of B/A is optimized, where the distance between an electrode pole to which strip-form lead pieces are welded, the lead pieces being formed intermittently in the winding direction, which is the longitudinal direction of the belt-like electrodes, and the inner wall of the battery can is represented by A, and the distance between the electrode pole and the wound electrode group is represented by B, in order to secure an exhaust passage for the gas generated upon occurrence of an abnormality in the battery.