Abstract: The invention provides an electrolyte solution capable of providing an electrochemical device having low resistance and excellent high-temperature storage characteristics and cycle characteristics. The electrolyte solution contains lithium fluorosulfonate and a solvent containing a compound (1) represented by the following formula (1):CF2HCOOCH3.

Abstract: There is provided a positive electrode for nonaqueous electrolyte secondary batteries having a high-density and a high folding strength. There is also provided a nonaqueous electrolyte secondary battery including such a positive electrode. The positive electrode has a high folding strength when it is used in a battery with a high current density, and a nonaqueous electrolyte secondary battery having such a positive electrode. The positive electrode has an electrode body having formed a folded portion at least at one part of the positive electrode. With respect to a cross-section of the positive electrode composition layer, a domain A extends from a central part to a surface side of a thickness direction, and a domain B extends from the central part to the current collector. The distribution of the binder in domain A and domain B are specified.

Abstract: A lithium secondary battery positive electrode according to the present invention is a lithium secondary battery positive electrode including a positive electrode material mixture layer containing a positive electrode active material and a conductivity enhancing agent on one or both sides of a current collector, wherein the positive electrode active material contains a lithium-containing composite oxide, the conductivity enhancing agent contains carbon fibers having an average fiber length of 10 nm or more and less than 1000 nm and an average fiber diameter of 1 nm or more and 100 nm or less, and the content of the carbon fibers in the positive electrode material mixture layer is 0.25 mass % or more and 1.5 mass % or less.

Abstract: A lithium secondary battery positive electrode according to the present invention is a lithium secondary battery positive electrode including a positive electrode material mixture layer containing a positive electrode active material and a conductivity enhancing agent on one or both sides of a current collector, wherein the positive electrode active material contains a lithium-containing composite oxide, the conductivity enhancing agent contains carbon fibers having an average fiber length of 10 nm or more and less than 1000 nm and an average fiber diameter of 1 nm or more and 100 nm or less, and the content of the carbon fibers in the positive electrode material mixture layer is 0.25 mass % or more and 1.5 mass % or less.

Abstract: A lithium secondary battery positive electrode of the present invention includes a positive electrode material mixture layer containing a positive electrode active material, a conductivity enhancing agent and a binder on one or both sides of a current collector, and the positive electrode active material contains a lithium-containing composite oxide represented by the general compositional formula: Li1+xMO2, where x is in a range of ?0.15?x?0.15 and M represents an element group of three or more elements including at least Ni, Co and Mn. The binder contains a tetrafluoroethylene-vinylidene fluoride copolymer (P(TFE-VDF)) and polyvinylidene fluoride (PVDF). The total content of the binder in the positive electrode material mixture layer is 1 to 4 mass %, and the ratio of the P(TFE-VDF) is 10 mass % or more, when the total of the P(TFE-VDF) and the PVDF is taken as 100 mass %.