A surface-treated steel sheet for a battery container includes a steel sheet, an iron-nickel diffusion layer formed on the steel sheet, and a nickel layer formed on the iron-nickel diffusion layer and constituting the outermost layer. When the Fe intensity and the Ni intensity are continuously measured from the surface of the surface-treated steel sheet for a battery container along the depth direction with a high frequency glow discharge optical emission spectrometric analyzer, the thickness of the iron-nickel diffusion layer being the difference (D2D1) between the depth (D1) at which the Fe intensity exhibits a first predetermined value and the depth (D2) at which the Ni intensity exhibits a second predetermined value is 0.04 to 0.31 m; and the total amount of the nickel contained in the iron-nickel diffusion layer and the nickel contained in the nickel layer is 10.8 to 26.7 g/m2.

A surface-treated steel sheet for a battery container includes a steel sheet, an iron-nickel diffusion layer formed on the steel sheet, and a nickel layer formed on the iron-nickel diffusion layer and constituting the outermost layer. When the Fe intensity and the Ni intensity are continuously measured from the surface of the surface-treated steel sheet for a battery container along the depth direction with a high frequency glow discharge optical emission spectrometric analyzer, the thickness of the iron-nickel diffusion layer being the difference (D2D1) between the depth (D1) at which the Fe intensity exhibits a first predetermined value and the depth (D2) at which the Ni intensity exhibits a second predetermined value is 0.04 to 0.31 m; and the total amount of the nickel contained in the iron-nickel diffusion layer and the nickel contained in the nickel layer is 10.8 to 26.7 g/m2.

A steel foil for a power storage device container includes a rolled steel foil, a nickel layer formed on a surface of the rolled steel foil, and a chromium-based surface treatment layer formed on a surface of the nickel layer. The nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe. <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0. The nickel layer has a sub-boundary which is a boundary between two crystals having a relative orientation difference of 2 to 5, and a large angle boundary which is a boundary between two crystals having the relative orientation difference of equal to or more than 15. The average value of a ratio L5/L15 between a boundary length L5 which is the length of the sub-boundary, and a boundary length L15 which is the length of the large angle boundary, is equal to or more than 1.0.

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.

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.

An enclosure for a prismatic battery cell include first side surfaces, second side surfaces connected between the first side surfaces, a top surface connected between the first side surfaces and the second side surfaces, and a bottom surface connected between the first side surfaces and the second side surfaces. The first side surfaces, the second side surfaces, the top surface and the bottom surface are configured to receive a battery cell stack. The second side surfaces, the top surface and the bottom surface expand/contract to allow guided expansion/contraction of the enclosure in a first direction while limiting expansion in second and third directions transverse to the first direction.

An enclosure for a prismatic battery cell include first side surfaces, second side surfaces connected between the first side surfaces, a top surface connected between the first side surfaces and the second side surfaces, and a bottom surface connected between the first side surfaces and the second side surfaces. The first side surfaces, the second side surfaces, the top surface and the bottom surface are configured to receive a battery cell stack. The second side surfaces, the top surface and the bottom surface expand/contract to allow guided expansion/contraction of the enclosure in a first direction while limiting expansion in second and third directions transverse to the first direction.

Provided are a surface-treated metal sheet which includes a nickel layer having improved corrosion resistance and a method of manufacturing a formed article. In a surface-treated metal sheet where a nickel layer is formed on a substrate, the proportion of the (200) plane to a total of the (111) plane, (200) plane, (220) plane and (311) plane with respect to the crystal plane orientations of the nickel layer is set to 40% or less. In a method of manufacturing a formed article using a surface-treated metal sheet where a nickel layer is formed on a substrate, the surface-treated metal sheet having the nickel layer where the proportion of the (200) plane to a total of the (111) plane, (200) plane, (220) plane and (311) plane is set to 40% or less with respect to the crystal plane orientations of the nickel layer is worked using a mold.

A method for manufacturing a tubular enclosure for a battery cell includes roll forming a sheet of steel into a tubular body. The steel comprises carbon in a range from 0.02 to 0.3 wt %, manganese in a range from 0.2 to 2.0 wt %, at least one of chromium and molybdenum in a range from 0.5 wt % to 3.0 wt %, silicon in a range from 0.2 wt % to 2.0 wt %, at least one of niobium, titanium, and vanadium in a range from 0.01 wt % to 0.2 wt %, and iron. The method includes welding sides of the tubular body to form a weld seam, heating the tubular body to a temperature in a range from 900 C. to 950 C., and quenching the tubular body.

A method for manufacturing a tubular enclosure for a battery cell includes roll forming a sheet of steel into a tubular body. The steel comprises carbon in a range from 0.02 to 0.3 wt %, manganese in a range from 0.2 to 2.0 wt %, at least one of chromium and molybdenum in a range from 0.5 wt % to 3.0 wt %, silicon in a range from 0.2 wt % to 2.0 wt %, at least one of niobium, titanium, and vanadium in a range from 0.01 wt % to 0.2 wt %, and iron. The method includes welding sides of the tubular body to form a weld seam, heating the tubular body to a temperature in a range from 900 C. to 950 C., and quenching the tubular body.