Abstract: A lithium ion secondary battery can suppress the deterioration of the insulating property of a positive electrode insulating layer by preventing the material of the positive electrode insulating layer from sinking into a positive electrode active material layer. A lithium ion secondary battery according is a lithium ion secondary battery including a positive electrode and a negative electrode that are laminated upon each other. The lithium ion secondary battery is characterized in that the positive electrode includes: a positive electrode foil; a positive electrode active material layer formed on a surface of the positive electrode foil; and a positive electrode insulating layer formed on a surface of the positive electrode active material layer, in which the positive electrode active material layer includes a positive electrode active material and a first nonaqueous binder, and the positive electrode insulating layer includes an inorganic filler, a second nonaqueous binder, and a dispersant.

Abstract: A lithium ion secondary battery is provided which has a sufficient discharge capacity and has a low internal resistance in a low SOC range. The lithium ion secondary battery includes: a positive electrode including a positive electrode mixture containing a positive electrode active material represented by the following formula: Li1+xMAO2; (where X satisfies ?0.15?X?0.15, MA represents a group of elements including at least one selected from the group consisting of Mn and Al, Ni, and Co.); and a negative electrode including a negative electrode mixture containing a negative electrode active material containing a carbon-based material, a negative electrode additive containing a copper oxide, and a binder, in which the negative electrode mixture contains the copper oxide in an amount of 0.5 wt % or more and 15 wt % or less based on the total weight of the negative electrode active material and the negative electrode additive.

Abstract: Provided is a positive electrode for a lithium ion secondary battery that suppresses both a decrease in discharge capacity and an increase in internal resistance due to charging and discharging. The positive electrode for the lithium ion secondary battery includes a positive-electrode current collector and a layered structure provided on the positive-electrode current collector, in which the outermost layer of the layered structure contains a first positive-electrode active material represented by Li1+XMAO2 wherein X satisfies ?0.15?X?0.15, MA represents an element group including Ni, Co, and Mn, and the innermost layer of the layered structure contains a second positive-electrode active material represented by Li1+YMBO2 wherein Y satisfies ?0.15?Y?0.15, and MB represents an element group including Ni, Co, and at least one of Mn or Al.