Disclosed is a secondary battery pouch film, including an outer layer, a metal layer, and a sealant layer, wherein the sealant layer includes a cast polypropylene (CPP) layer and an extruded polypropylene (PP) layer, and the secondary battery pouch film satisfies the [Equation 1] where A+B<1.354, 0.6?C. In [Equation 1], A is a value obtained by dividing a thickness of the metal layer by a total thickness of the secondary battery pouch film, B is a value obtained by dividing a thickness of the metal layer by a thickness of the sealant layer, and C is a value obtained by dividing a thickness of the extruded polypropylene (PP) layer of the sealant layer by a thickness of the cast polypropylene (CPP) layer of the sealant layer. The pouch film has excellent formability, curling, insulation, bending, and peel strength.

A steel foil for a power storage device container includes a rolled steel foil which has a thickness of 200 m or less, a diffusion alloy layer which is formed on a surface layer of the rolled steel foil and contains Ni and Fe, and a chromium-based surface treatment layer which is formed on the diffusion alloy layer. The <111> polar density in a reverse pole figure of the diffusion alloy layer in a rolling direction is 2.0 to 6.0, and the aspect ratio of crystal in a surface of the diffusion alloy layer is 1.0 to 5.0.

In a battery packaging material in which a substrate protective layer, a substrate layer, a barrier layer, and a heat-fusible resin layer are laminated in this order, the substrate protective layer is formed of a resin composition containing a resin component and solid fine particles. The Young's modulus of the substrate protective layer measured by a method specified in JIS K7127 is 0.5 MPa to 3 MPa, and the tensile strength at 40% elongation measured by a method specified in JIS K7127 is 5 MPa to 20 MPa.

An exterior material for a power storage device, the exterior material being configured from a layered body that includes at least a substrate layer, a barrier layer, and a thermally fusible resin layer in this order, wherein in the thermally fusible resin layer, the molecular weight that is the peak value in a differential molecular weight distribution curve measured using high-temperature gel permeation chromatography is 150,000 or greater.

An exterior material for a power storage device, the exterior material being configured from a layered body that includes at least a substrate layer, a barrier layer, and a thermally fusible resin layer in this order, wherein in the thermally fusible resin layer, the molecular weight that is the peak value in a differential molecular weight distribution curve measured using high-temperature gel permeation chromatography is 150,000 or greater.

A battery packaging material includes a laminate that includes at least a base material layer, a metal layer, an insulating layer, and a sealant layer laminated in this order. The insulating layer is formed of a resin composition containing a modified polyolefin resin modified with an unsaturated carboxylic acid or acid anhydride thereof and has a hardness, when measured by using a nanoindenter and pressing an indenter 5 ?m into the insulating layer from a cross-section of the laminate in the laminating direction thereof, that ranges from 10 MPa to 300 MPa. In the sealant layer, an elastic modulus, when measured by using a nanoindenter and pressing an indenter 5 ?m into the sealant layer from a cross-section of the laminate in the laminating direction thereof, ranges from 100 MPa to 1000 MPa.

A power-cell packaging material including a layered body obtained by layering at least a substrate layer, a metal layer, an insulating layer, and a sealant layer, in this order. The insulating layer has a hardness in the range of 10-300 MPa, when measured by using a nanoindenter and pressing the indenter 5 ?m into the insulating layer from a cross-section of the layered body in the layering direction thereof.

The present application provides a top cap assembly and a battery structure. The battery includes a housing including a mounting hole, and the top cap assembly passes through the mounting hole of the housing. The top cap assembly includes a pole, a sealing element, and a plastic element. The pole is provided with an annular groove recessed in a radial direction. The sealing element is sleeved on the pole and positioned in the annular groove. The sealing element is sandwiched between the housing and a groove wall of the annular groove, and the sealing element is partially positioned outside the housing. The plastic element is sleeved on the sealing element and positioned outside the housing, and the plastic element is partially sandwiched between the housing and the groove wall of the annular groove.

The present application provides a top cap assembly and a battery structure. The battery includes a housing including a mounting hole, and the top cap assembly passes through the mounting hole of the housing. The top cap assembly includes a pole, a sealing element, and a plastic element. The pole is provided with an annular groove recessed in a radial direction. The sealing element is sleeved on the pole and positioned in the annular groove. The sealing element is sandwiched between the housing and a groove wall of the annular groove, and the sealing element is partially positioned outside the housing. The plastic element is sleeved on the sealing element and positioned outside the housing, and the plastic element is partially sandwiched between the housing and the groove wall of the annular groove.

An electrochemical cell, preferably a secondary, rechargeable cell, including a casing comprised of a main body portion having opposed lower and upper open ends closed by respective lower and upper lids is described. The main body portion is composed of titanium Grades 5 or 23 having a relatively high electrical resistivity material while the lower and upper lids are composed of titanium Grades 1 or 2. The lids are preferably joined to the main body portion using laser welding. The combination of these differing titanium alloys provides a cell casing that effectively retards eddy current induced heating during cell recharging.