Panasonic Energy Co., Ltd.

A battery pack includes a plurality of secondary battery cells, each of which has a cylindrical outer can and includes one or more gas discharge ports on a circular end face of the outer can, an outer case that stores the plurality of secondary battery cells, and one or more lead plates coupled to one or more end faces of the plurality of secondary battery cells. The battery pack also includes a path defining portion that defines a gas discharge path, disposed to face at least one of the one or more gas discharge ports. The path defining portion defines a first path along a first direction that extends from a center toward a circumference of a circular shape of an end face of the outer can, and a second path along a second direction that extends from the circumference toward the center of the circular shape of the end face of the outer can.

According to the present invention, a negative electrode of a wound electrode body has a non-facing part which is wound 1.25 turns or more without facing a positive electrode from a facing part that faces the inner winding surface of a leading end of the positive electrode in the winding direction toward the winding start side. The non-facing part has, sequentially from the facing part toward the winding start side, a first negative electrode mixture layer formed part where a negative electrode mixture layer is provided on at least one surface of a negative electrode core body, a first negative electrode core body exposed part where the negative electrode core body is exposed, and a second negative electrode mixture layer formed part where the negative electrode mixture layer is provided on at least one surface of the negative electrode core body.

A method for separating a transition metal and Li includes a step of allowing a compound containing Li and a transition metal to react with a carboxylic acid in water, to obtain a slurry containing a first solution containing Li ions and a precipitate containing a transition metal carboxylate, and a step of separating the precipitate from the first solution. The transition metal is at least one selected from the group consisting of Ni, Co, Mn, Ti, Fe, and Cu.

The non-aqueous electrolyte secondary battery according to an aspect of the present disclosure comprises: a wound electrode body on which a strip-like positive electrode and a strip-like negative electrode are each wound with a separator interposed therebetween; and an outer package accommodating the electrode body. The positive electrode comprises a positive current collector and a positive mixture layer that is formed on the positive current collector and contains at least a positive active material and a binder. The negative electrode comprises a negative current collector and a negative mixture layer that is formed on the negative current collector and contains at least a negative active material and a binder. At least one of the positive mixture layer and the negative mixture layer has a binder content that is higher on a leading end than on a terminal end.

In a non-aqueous electrolyte secondary battery according to one embodiment of the present invention, a positive electrode ( 11 ) has: a positive electrode core material ( 30 ); and a positive electrode mixture layer ( 31 ) formed on the surface of the positive electrode core material ( 30 ). The electrode mixture layer ( 31 ) contains, as a positive electrode active material, first lithium metal composite oxide particles that are non-aggregated particles having a volume-based median diameter of 2-10 μm, and second lithium metal composite oxide particles that are secondary particles that have a volume-based median diameter of 10-30 μm and that are each obtained by aggregation of primary particles having an average particle diameter from 50 nm to 2 μm. The first lithium metal composite oxide particles are contained more in a first region ( 31 a ) than in a second region ( 31 b ). A non-aqueous electrolyte contains a diisocyanate compound.

A disclosed battery includes an electrode group formed by winding a first electrode and a second electrode with a separator interposed therebetween, and a first current collector plate having at least one welded portion welded to the first electrode. The first current collector plate has at least a pair of magnetized portions that are arranged to sandwich the welded portion and are magnetized. A magnetic force of the welded portion is smaller than a magnetic force of the magnetized portions.

A gasket has: an annular part that abuts the bottom surface of a sealing body; a bottom part that is positioned closer than the annular part to an electrode body and that presses the electrode body; and a coupling part that couples the annular part and the bottom part and that inclines towards the center in the radial direction with proximity to the bottom part. The bottom part is provided with a first through hole that is positioned so as to include the center in the radial direction, and a plurality of second through holes that are positioned at a peripheral part.

A battery includes a case, an electrode group, a sealing unit including a conductive cap, a terminal plate joined to an opening edge of the case, and an insulating plate that electrically insulates the conductive cap from the terminal plate. The case and the terminal plate are electrically connected to a first electrode, while the conductive cap is electrically connected to a second electrode. The terminal plate has a first connection region to which a first external terminal is to be connected. The conductive cap has a second connection region to which a second external terminal is to be connected. The terminal plate has a planned breaking part between the first connection region and a joint part thereof joined to the opening edge of the case. The planned breaking part breaks when the internal pressure of the case exceeds a predetermined value, separating the terminal plate in the axial direction of the case into a broken piece on the outer peripheral side and a broken piece on the inner peripheral side.

A disclosed method for separating a transition metal and Li includes: a step of dissolving a compound containing Li and a transition metal in a carboxylic acid, to obtain a first solution containing Li ions, Ni ions, and carboxylic acid anions; a step of adding an alkali to the first solution, to obtain a second solution containing Li ions, and a precipitate containing a transition metal carboxylate; and a step of separating the precipitate from the second solution. The transition metal is at least one selected from the group consisting of Ni, Co, Mn, Ti, Fe, and Cu.

This non-aqueous electrolyte secondary battery is characterized by having a positive electrode, a negative electrode, and a non-aqueous electrolyte, wherein the positive electrode has a positive electrode current collector and a positive electrode mixture layer provided on the positive electrode current collector, the positive electrode mixture layer includes a positive electrode active material and a dielectric, and the ratio (D50 of the dielectric/D50 of the positive electrode active material) of a volume-based median diameter (D50) of the dielectric to a volume-based median diameter (D50) of the positive electrode active material is 0.15-0.6.