Abstract: A rechargeable lithium battery including a negative electrode made by sintering, on a surface of a conductive metal foil as a current collector, a layer of a mixture of active material particles containing silicon and/or a silicon alloy and a binder, a positive electrode and a nonaqueous electrolyte, characterized in that the nonaqueous electrolyte contains carbon dioxide dissolved therein.

Abstract: A lithium secondary battery having high capacity and good charge-discharge cycle performance is provided. The lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a positive electrode active material, and a non-aqueous electrolyte. The positive electrode active material is a lithium-transition metal composite oxide including a layered structure represented by the chemical formula LiaNixMnyCozO2, where a, x, y, and z satisfy the expressions: 0?a?1.3, x+y+z=1, 0<x, 0?y?0.5, and 0?z.), and the theoretical electrical capacity ratio of the positive electrode to the negative electrode (positive electrode/negative electrode) is 1.2 or less.

Abstract: An object of the invention is to provide a non-aqueous electrolyte secondary battery that allows a good charge/discharge cycle characteristic to be obtained. The non-aqueous electrolyte secondary battery according to the invention includes a negative electrode containing silicon as a negative electrode active material, a positive electrode, and a non-aqueous electrolyte, the average particle size of the negative electrode active material is not less than 5 ?m nor more than 20 ?m, and the weight of the negative electrode active material is at least 10% of the weight of the non-aqueous electrolyte.

Abstract: A cylindrical lithium secondary battery includes a positive electrode (1) having a positive electrode mixture layer disposed on a surface of a positive electrode current collector made of a conductive metal foil and containing a positive electrode active material, and a negative electrode (2) having a negative electrode mixture layer disposed on a surface of a negative electrode current collector made of a conductive metal foil and having a negative electrode active material containing silicon particles and/or silicon alloy particles. The amount of the positive electrode active material is 50 mg or less per 1 cm2 of the positive electrode, the average particle size of the silicon particles and/or silicon alloy particles is from 5 ?m to 15 ?m, and the theoretical electrical capacity ratio of the negative electrode to the positive electrode is 1.2 or greater.

Abstract: In a lithium secondary battery using negative electrode active material particles containing silicon, excellent charge-discharge characteristics are achieved and swelling of the negative electrode is minimized. A lithium secondary battery has a positive electrode containing a positive electrode active material, a negative electrode containing an active material layer and a current collector made of a conductive metal foil, and a non-aqueous electrolyte. The active material layer has a binder and active material particles containing silicon, and is formed by sintering the active material layer on a current collector surface in a non-oxidizing atmosphere. The active material particles have an average particle size of from 7.5-15 ?m and a particle size distribution such that 60 volume % or more of the active material particles falls within the ±40% range of the average particle size, and the lithium secondary battery has a negative/positive electrode capacity ratio of 1.7 or greater.

Abstract: A lithium secondary battery is provided capable of significantly improving charge-discharge cycle performance by preventing gas generation originating from decomposition of the non-aqueous electrolyte while preventing manufacturing cost from increasing. A lithium secondary battery is provided with: a power generating element accommodated in a flexible battery case (6), the power generating element including a negative electrode (2), a positive electrode (1), and a non-aqueous electrolyte. The negative electrode contains negative electrode active material particles composed of silicon and/or a silicon alloy. The positive electrode contains a positive electrode active material composed of a lithium-transition metal composite oxide. The non-aqueous electrolyte contains ions of at least one element selected from the group consisting of Co, Cu, Mg, Mn, Ni, Fe, and Zr.

Abstract: Charge-discharge cycle performance is improved in a lithium secondary battery utilizing a material containing silicon as a positive electrode active material. A lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a lithium-transition metal composite oxide, and a non-aqueous electrolyte. Lithium carbonate is added in the positive electrode (1), and carbon dioxide is dissolved in the non-aqueous electrolyte.

Abstract: A lithium secondary battery having high capacity and good charge-discharge cycle performance is provided. The lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a positive electrode active material, and a non-aqueous electrolyte. The positive electrode active material is a lithium-transition metal composite oxide including a layered structure represented by the chemical formula LiaNixMnyCOzO2, where a, x, y, and z satisfy the expressions: 0?a?1.3, x+y+z=1, 0<x, 0?y?0.5, and 0?z.), and the theoretical electrical capacity ratio of the positive electrode to the negative electrode (positive electrode/negative electrode) is 1.2 or less.

Abstract: A rechargeable lithium battery including a negative electrode made by sintering, on a surface of a conductive metal foil as a current collector, a layer of a mixture of active material particles containing silicon and/or a silicon alloy and a binder, a positive electrode and a nonaqueous electrolyte, characterized in that the nonaqueous electrolyte contains carbon dioxide dissolved therein.