Abstract: An electrode structure for a secondary battery includes an electrode and a composite layer. In a cumulative frequency distribution of inorganic particles having average particle size of 3 ?m or more with respect to a thickness direction of the composite layer, a first region is set to a range 0 or more and less than 25 and the second region is set to a range 25 or more and 100 or less. The first region is 5% or more and 40% or less of the thickness of the composite layer. Average particle size of inorganic particles satisfy a relationship of R1<R2.

Abstract: An integrated sheet structure for a secondary battery, including a first mixture layer containing a first active material and a first binder, a second mixture layer containing a second active material and a second binder, and a third mixture layer located between the first mixture layer and the second mixture layer and containing solid particles and a third binder, in which the first mixture layer and the third mixture layer are bonded each other, and the second mixture layer and the third mixture layer are bonded each other.

Abstract: In one embodiment, there is provided a charging method of a battery pack in which a plurality of aqueous battery cells are electrically connected in series. In this charging method, in a case where the battery pack reaches a reference voltage by a constant-current charging at a first charging rate, constant-current charging is performed on the battery pack at the second charging rate lower than the first charging rate and being from 0.01 C or more to 0.05 C or less. Then, this constant-current charging at the second charging rate is continued until a charged electric charge amount from a start timing of the constant-current charging at the second charging rate reaches a reference electric charge amount set from 1% or more to 5% or less of the nominal capacity of the battery pack.

Abstract: Provided is a secondary battery including a negative electrode, a positive electrode, a separation layer in contact with an active material-containing layer of the negative electrode, and an aqueous electrolyte. A first concentration corresponding to a first metal concentration represented by Equation 1 (first metal concentration=atomic concentration of Hg, Pb, Zn, and/or Bi/sum of atomic concentrations of elements B to U in periodic table, excluding carbon and oxygen) in a boundary region between the active material-containing layer and the separation layer is 2% or more and 8.2% or less. A ratio of the first concentration to a second concentration corresponding to the first metal concentration represented by Equation 1 in the active material-containing layer excluding the boundary region is 2.5 or more and less than 4.

Abstract: According to one embodiment, a secondary battery (100) including a positive electrode (5), a negative electrode (3), a first electrolyte (9), and a second electrolyte (8). The negative electrode (3) includes a lithium titanium oxide having a degree of proton substitution of 0.01 to 0.2. The first electrolyte (9) includes water and in contact with the positive electrode (5). The second electrolyte (8) includes water and in contact with the negative electrode (3).

Abstract: According to one embodiment, provided is a secondary battery including an aqueous electrolyte, a positive electrode, and a negative electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material-containing layer. The negative electrode current collector includes a first metallic substance including one or more element MA selected from Sn, Ni, Cu, Pb, and Ti. A surface of the negative electrode active material-containing layer includes the first metallic substance and a second metallic substance including one or more element MB selected from Hg, Zn, Pb, Sn, Cd, Pd, Al, Bi, and In. A ratio PA/(PA+PB) of an abundance PA of element MA and an abundance PB of element MB on the surface of the negative electrode active material-containing layer is 0.01 or more.

Abstract: According to one embodiment, a separator is provided. The separator includes a composite membrane. The composite membrane includes a substrate layer, a first composite layer, and a second composite layer. The first composite layer is located on one surface of the substrate layer. The second composite layer is located on the other surface of the substrate layer. The composite membrane has a coefficient of air permeability of 1×10?14 m2 or less. The first composite layer has a first surface and a second surface. The first surface is in contact with the substrate layer. The second surface is located on an opposite side to the first surface. Denseness of a portion including the first surface is lower than denseness of a portion including the second surface in the first composite layer.

Abstract: According to one embodiment, a battery includes a container member, a separator, a first electrode, a first electrolyte, a second electrode and a second electrolyte. The container member has a housing space in the interior, and the separator is housed in the housing space of the container member. The separator includes a bag, and the first electrode is housed in an interior of the bag. The first electrolyte is retained on the first electrode in the interior of the bag. The second electrode is located outside the bag in the housing space. The second electrolyte is retained by the second electrode outside the bag in the housing space.

Abstract: According to one embodiment, a secondary battery is provided. The secondary battery includes: a positive electrode containing a positive electrode active material; a negative electrode; a separator arranged between the positive electrode and the negative electrode; and a first aqueous electrolyte held in at least the positive electrode. pH of the first aqueous electrolyte is more than 7. The positive electrode active material contains a lithium-containing compound that exhibits an average operating potential of less than 4.0 V based on lithium metal.

Abstract: A secondary battery includes a positive electrode, a first aqueous electrolyte held on the positive electrode, a negative electrode, a second aqueous electrolyte held on the negative electrode, and a separator interposed between the positive electrode and the negative electrode. A difference between an osmotic pressure (N/m2) of the first aqueous electrolyte and an osmotic pressure (N/m2) of the second aqueous electrolyte is 90% or less (including 0%) of the higher one of the osmotic pressure of the first aqueous electrolyte and the osmotic pressure of the second aqueous electrolyte.

Abstract: In one embodiment, a secondary battery is provided, which includes an electrolytic solution, and a positive electrode and a negative electrode which are immersed in the electrolytic solution. The electrolytic solution contains water, an electrolyte salt, and at least one kind of an organic solvent with a relative permittivity of not more than 42. The relative permittivity of the electrolytic solution fractionated when converted according to a volume fraction is not more than 78.50.

Abstract: According to one embodiment, a secondary battery (100) including a positive electrode (5), a negative electrode (3), a first electrolyte (9), and a second electrolyte (8). The negative electrode (3) includes a lithium titanium oxide having a degree of proton substitution of 0.01 to 0.2. The first electrolyte (9) includes water and in contact with the positive electrode (5). The second electrolyte (8) includes water and in contact with the negative electrode (3).

Abstract: According to one embodiment, an electrode structure is provided. The electrode structure includes an electrode group and a hold member. The hold member clamps the electrode group in a thickness direction of the electrode group. The electrode group satisfies a formula (1) below. m/L?0.01??(1) Here, m is a difference ?t in a cross section which is selected from among a plurality of cross sections along the thickness direction of the electrode group. L is a maximum length of the electrode group in an in-plane direction orthogonal to the thickness direction.

Abstract: According to one embodiment, a secondary battery is provided. The secondary battery includes a positive electrode, a negative electrode, and an aqueous electrolyte containing alkali metal ions. The aqueous electrolyte contains an organic compound containing a carboxyl group or carboxylate group and a hydroxyl group. The pH of the aqueous electrolyte is 0 or less. The ratio of the weight of the organic compound to the weight of the aqueous electrolyte is within a range of 0.01% by weight to 6.5% by weight. The number of carbon atoms in the organic compound is 5 or more.

Abstract: A secondary battery includes a positive electrode, a first aqueous electrolyte held on the positive electrode, a negative electrode, a second aqueous electrolyte held on the negative electrode, and a separator interposed between the positive electrode and the negative electrode. A difference between an osmotic pressure (N/m2) of the first aqueous electrolyte and an osmotic pressure (N/m2) of the second aqueous electrolyte is 90% or less (including 0%) of the higher one of the osmotic pressure of the first aqueous electrolyte and the osmotic pressure of the second aqueous electrolyte.

Abstract: According to one embodiment, a separator is provided. The separator includes a composite membrane. The composite membrane includes a substrate layer, a first composite layer, and a second composite layer. The first composite layer is located on one surface of the substrate layer. The second composite layer is located on the other surface of the substrate layer. The composite membrane has a coefficient of air permeability of 1×10?14 m2 or less. The first composite layer has a first surface and a second surface. The first surface is in contact with the substrate layer. The second surface is located on an opposite side to the first surface. Denseness of a portion including the first surface is lower than denseness of a portion including the second surface in the first composite layer.

Abstract: A secondary battery including an aqueous electrolyte, a positive electrode, and a negative electrode. The negative electrode includes a negative electrode active material which contains a Ti-containing composite oxide. At least one element A selected from Hg, Pb, Zn, and Bi is present on a surface of the negative electrode. An average of molar ratios (A/(A+Ti)) of the element A ranges from 5% to 40%. Each of the molar ratios is a molar amount of the element A to a sum between the molar amount of the element A and a molar amount of Ti on the surface of the negative electrode, according to scanning electron microscopy-energy dispersive X-ray spectroscopy.

Abstract: According to one embodiment, there is provided a secondary battery including a positive electrode, a negative electrode, and an aqueous electrolyte. The negative electrode contains a titanium-containing oxide. The aqueous electrolyte contains a solvent and alkali metal ions or alkaline earth metal ions, the solvent containing water and a water-soluble organic solvent. An interfacial tension of the aqueous electrolyte is 37 mN/m or less.

Abstract: According to one embodiment, a battery includes a container member, a separator, a first electrode, a first electrolyte, a second electrode and a second electrolyte. The container member has a housing space in the interior, and the separator is housed in the housing space of the container member. The separator includes a bag, and the first electrode is housed in an interior of the bag. The first electrolyte is retained on the first electrode in the interior of the bag. The second electrode is located outside the bag in the housing space. The second electrolyte is retained by the second electrode outside the bag in the housing space.

Abstract: According to one embodiment, a secondary battery is provided. The secondary battery includes a negative electrode, a positive electrode, a first aqueous electrolyte, a second aqueous electrolyte, and a partition having a first surface and a second surface opposite to the first surface. The partition is positioned between the negative electrode and the positive electrode. The first aqueous electrolyte is in contact with the first surface of the partition and the negative electrode. The second aqueous electrolyte is in contact with the second surface of the partition and the positive electrode. The partition contains a solid electrolyte having alkali metal ion conductivity. The first aqueous electrolyte includes an organic compound.