Abstract: A secondary battery disclosed herein includes a positive electrode, and a negative electrode containing a negative electrode active material. The negative electrode active material contains a carbon material and a silicon-containing material. The average particle diameter of the silicon-containing material is smaller than the average particle diameter of the carbon material. The average circularity of the silicon-containing material is smaller than the average circularity of the carbon material.

Abstract: A secondary battery disclosed herein includes a positive electrode, and a negative electrode containing a negative electrode active material. The negative electrode active material contains a carbon material and a silicon-containing material. The silicon-containing material includes a first silicon-containing material and a second silicon-containing material. The average particle diameter of the first silicon-containing material and the average particle diameter of the second silicon-containing material are each smaller than the average particle diameter of the carbon material. The average circularity Zc of the carbon material, the average circularity Zs1 of the first silicon-containing material, and the average circularity Zs2 of the second silicon-containing material satisfy Zs1<Zc and Zs1<Zs2.

Abstract: A negative electrode slurry for a lithium ion secondary battery, according to an aspect of the present disclosure, comprises a negative electrode active material, a thickener, a preservative component, and a solvent, the thickener comprising carboxymethyl-cellulose or a salt thereof, the solvent comprising water, and the preservative component comprising a cyclic hydroxamic acid ethanolamine salt.

Abstract: A negative electrode slurry for a lithium ion secondary battery, according to the present disclosure, is characterized by comprising a negative electrode active material, a thickener, a preservative component, and a solvent, the thickener comprising carboxymethyl-cellulose or a salt thereof, the solvent comprising water, and the preservative component comprising a compound having a tropone skeleton.

Abstract: A negative electrode material mixture with a negative electrode active material including a Si-containing material and a carbon material; and a carbon nanotube. The Si-containing material includes, a first composite material in which Si particles are dispersed in a lithium silicate phase and/or a carbon phase, and a second composite material in which Si particles are dispersed in a SiO2 phase, at least the first composite material. A mass ratio X of the first composite material to a total of the first and second composite materials, and a mass ratio Y of the total of the first second composite materials to a total of the first composite material, the second composite material, and the carbon material satisfy a relational expression (1): 100Y?32.2X5+65.479X4?55.832X3+18.116X2?6.9275X?3.5356<0, X?1, and 0.06?Y. The non-aqueous electrolyte includes LiPF6 and LiN(SO2F)2.