Abstract: A negative electrode active material layer and a solid-state battery, which can exhibit the inherent performance of porous silicon particles, are provided. The negative electrode active material layer of the present disclosure contains porous silicon particles, graphite particles, and inorganic solid electrolyte particles, and the ratio of the mass of the graphite particles to the total mass of the porous silicon particles and the graphite particles is 10 mass % to 25 mass %. In addition, the solid-state battery of the present disclosure comprises the negative electrode active material layer of the present disclosure, the solid electrolyte layers, and the positive electrode active material layer in this order.

Abstract: A secondary battery system of the present disclosure includes a secondary battery and a heating device, wherein the secondary battery includes a positive electrode and a negative electrode, and one or both of the positive electrode and the negative electrode include an active material and a granulated body, the active material includes a material whose volume changes with charge and discharge of the secondary battery, the granulated body includes an inorganic solid electrolyte and an alkali metal-containing salt, and a target heated by the heating device includes the alkali metal-containing salt.

Abstract: Provided is a technique for suppressing the formation of black regions in a wound electrode body. The production method disclosed herein is a method for producing a non-aqueous electrolyte secondary battery that includes a wound electrode body, a non-aqueous electrolyte, and a battery case. This production method includes the following steps: an assembling step S1 of placing the wound electrode body and the non-aqueous electrolyte in the battery case to construct a secondary battery assembly; a first step S2 of performing initial charging on the secondary battery assembly; and a second step S3 of setting the temperature of the wound electrode body to 50° C. or lower and keeping this state for at least 72 hours after the first step.

Abstract: Provided is a technique for preventing plastic deformation of a battery case due to restraint during initial charging. A manufacturing method disclosed herein is a manufacturing method of a non-aqueous electrolyte solution secondary battery. This method includes assembling to construct a secondary battery assembly, and initial charging of the secondary battery assembly. In the initial charging, the initial charging is started with the secondary battery assembly restrained or not restrained; when a negative electrode potential of the secondary battery assembly reaches 0.6 V, a restraint force P1 is applied to the secondary battery assembly, wherein the restraint force P1 is greater than a restraint force applied before the negative electrode potential reaches 0.6 V; and the restraint force P1 is applied to the secondary battery assembly until the negative electrode potential reaches at least 0.3 V.

Abstract: Provided is a technique for suppressing the formation of highly resistive regions in a wound electrode body. The production method disclosed herein includes a flat-shaped wound electrode body in which a belt-shaped positive electrode plate and a belt-shaped negative electrode plate are wound, with a belt-shaped separator being intervened therebetween, a non-aqueous electrolyte, and a battery case. The positive electrode plate contains a lithium-transition metal composite oxide containing manganese. This production method includes an assembling step S1 of placing the wound electrode body and the non-aqueous electrolyte in the battery case to construct a secondary battery assembly; a first charging step S2 of performing initial charging on the secondary battery assembly such that the battery voltage reaches 3.1 V to 3.7 V; and a discharging step S3 of discharging the secondary battery assembly after the first charging step.

Abstract: Provided is a technique for suppressing the formation of black regions in a wound electrode body. The production method disclosed herein is a method for producing a non-aqueous electrolyte secondary battery that includes a wound electrode body, a non-aqueous electrolyte, and a battery case. This production method includes the following steps: an assembling step S1 of placing the wound electrode body and the non-aqueous electrolyte in the battery case to construct a secondary battery assembly; a first step S2 of performing initial charging on the secondary battery assembly; and a second step S3 of setting the temperature of the wound electrode body to 50° C. or lower and keeping this state for at least 72 hours after the first step.