Abstract: Provided is a technique capable of improving impregnation efficiency of a nonaqueous electrolyte into an electrode body. A manufacturing method herein disclosed includes producing a negative pressure in an inside of a battery case; introducing a nonaqueous electrolyte into the inside of the battery case; establishing communication between the inside of the battery case and external atmosphere; temporarily sealing a solution introduction port using a first sealing member, impregnating the electrode body with a nonaqueous electrolyte; opening the solution introduction port; and, sealing the solution introduction port using a second sealing member. Herein, the first sealing member includes an air permeable film. Air permeation is enabled between the inside of the battery case after the temporary sealing and external atmosphere. The permeability of a vapor derived from the nonaqueous electrolyte with respect to the film is smaller than the permeability of water vapor.

Abstract: Provided is a technique capable of suppressing the occurrence of uneven drying inside an electrode body. The manufacturing method disclosed herein is for manufacturing a secondary battery comprising an electrode body and a battery case. The method comprises the steps of: accommodating the electrode body in the battery case to produce a battery assembly; arranging a gripping tool on the outside of the battery case of the battery assembly and gripping the battery assembly with the gripping tool; and drying the inside of the battery assembly, wherein the battery assembly is gripped and heated. In the gripping, a larger restraining pressure is applied to a central region of a rectangular surface of the electrode body than to other regions.

Abstract: Provided is a technique capable of suppressing the occurrence of uneven drying inside an electrode body. A secondary battery disclosed herein includes an electrode body and a battery case. The battery case has a pair of rectangular wide surfaces and four rectangular side surfaces between the pair of wide surfaces. The electrode body is accommodated in the battery case, wherein rectangular surfaces of the electrode body face the wide surfaces of the battery case. The battery case is provided with protrusions inside, and the protrusions are in contact with at least a part of a central region including a center line in the long side direction of the rectangular surfaces of the electrode body accommodated in the battery case.

Abstract: Provided is a technique capable of improving impregnation efficiency of a nonaqueous electrolyte into an electrode body. A manufacturing method herein disclosed includes producing a negative pressure in an inside of a battery case; introducing a nonaqueous electrolyte into the inside of the battery case; establishing communication between the inside of the battery case and external atmosphere; temporarily sealing a solution introduction port using a first sealing member, impregnating the electrode body with a nonaqueous electrolyte; opening the solution introduction port; and, sealing the solution introduction port using a second sealing member. Herein, the first sealing member includes an air permeable film. Air permeation is enabled between the inside of the battery case after the temporary sealing and external atmosphere. The permeability of a vapor derived from the nonaqueous electrolyte with respect to the film is smaller than the permeability of water vapor.