Abstract: In general, according to one embodiment, an ionic liquid is provided. The ionic liquid includes a cation including a trialkylsulfonium ion and a lithium ion. The ionic liquid further includes an anion including at least one of [N(FSO2)2]? or [N(CF3SO2)2]?. A molar ratio between the lithium ion and the trialkylsulfonium ion is in a range of 1:4 to 4:1. A molar ratio between [N(FSO2)2]? and [N(CF3SO2)2]? is in a range of 4.2:1 to 1:0.

Abstract: According to one embodiment, there is provided an electrode including active material particles, polymer fibers and inorganic solid particles. The polymer fibers have an average fiber diameter of 1 nm to 100 nm.

Abstract: According to one embodiment, a secondary battery includes a positive electrode, a negative electrode, a separator layer, and a nonaqueous electrolytic solution. The separator layer includes a first porous layer containing a solid electrolyte and a second porous layer containing fibers. The second porous layer is in contact with a first surface of the first porous layer. The nonaqueous electrolytic solution includes a first solvent including at least one of methyl propionate and ethyl propionate, and a second solvent different from the first solvent. The first porous layer has a void fraction of 10% by volume or greater and 50% by volume or less. The second porous layer has a void fraction greater than the void fraction of the first porous layer.

Abstract: According to one embodiment, a secondary battery includes a positive electrode, a negative electrode, a nonaqueous electrolyte and a separator. The positive electrode includes a halide including at least one metal element selected from the group consisting of copper, iron, nickel, cobalt, tin, and zinc. The negative electrode includes at least one selected from the group consisting of lithium metal, a lithium alloy, and a compound capable of having Li inserted and extracted. The nonaqueous electrolyte includes an ionic liquid including chlorine ions. The separator has lithium ion conductivity, and is interposed between the positive electrode and the negative electrode.

Abstract: According to one embodiment, a secondary battery including a negative electrode. The negative electrode includes a negative electrode current collector and a negative electrode mixture layer. A thickness of the negative electrode current collector is in a range of 8 ?m to 18 ?m. The negative electrode current collector includes a first current collector end surface extending along a stacking direction. The negative electrode mixture layer includes a niobium-titanium composite oxide, and a first protrusion protruding from the first current collector end surface along a first direction orthogonal to the stacking direction. A protrusion length A1 of the first protrusion satisfies 0 mm<A1?1.0 mm.

Abstract: According to one embodiment, an electrode structure is provided. The electrode structure includes: the current collector; the active material-containing layer provided on at least one surface of the current collector; and the organic fiber layer provided on the active material-containing layer. The organic fiber layer includes: the first region facing the active material-containing layer; and the second region adjacent to the first region, present on the center side of the main surface of the organic fiber layer, and facing the active material-containing layer. The density D1 of the first region of the organic fiber layer is higher than the density D2 of the second region of the organic fiber layer.

Abstract: According to one embodiment, a method of producing a secondary battery is provided. The method includes preparing a battery architecture including a positive electrode, a negative electrode, and an electrolyte; adjusting a positive electrode potential to a range of 3.4 V to 3.9 V and a negative electrode potential to a range of 1.5 V to 2.0 V based on an oxidation-reduction potential of lithium, thereby providing a potential adjusted state; and holding the battery architecture in the potential adjusted state at a holding temperature of 50° C. to 90° C. The positive electrode includes a lithium-nickel-cobalt-manganese composite oxide. The negative electrode includes a niobium-titanium composite oxide. The electrolyte includes one or more first organic solvent having a viscosity of 1 cP or less.

Abstract: According to one embodiment, an electrode is provided. The active material-containing layer includes an active material, inorganic solid particles having lithium ion conductivity, and carbon fiber. A pore diameter DM at the first peak is 0.05 ?m to 10 ?m. A value SA?SB is 1.4 or more in a slope distribution curve of the active material-containing layer, where a vertical axis of the slope distribution curve represents a slope of a straight line passing through two adjacent measurement points on the log differential pore volume distribution curve and a horizontal axis of the slope distribution curve represents a smaller pore diameter of the two adjacent measurement points. The value SA?SB is obtained by subtracting a minimum slope value SB from a maximum slope value SA.

Abstract: According to one embodiment, an electrode is provided. The electrode includes a current collector, a first layer formed on the current collector, and a second layer formed on at least part of the first layer. The first layer contains a monoclinic niobium titanium composite oxide. The second layer contains lithium titanate having a spinel structure. A porosity P2 of the second layer is within a range from 30% to 80%.

Abstract: According to one embodiment, a secondary battery includes a positive electrode, a negative electrode, a separator layer, and a nonaqueous electrolytic solution. The separator layer includes a first porous layer containing a solid electrolyte and a second porous layer containing fibers. The second porous layer is in contact with a first surface of the first porous layer. The nonaqueous electrolytic solution includes a first solvent including at least one of methyl propionate and ethyl propionate, and a second solvent different from the first solvent. The first porous layer has a void fraction of 10% by volume or greater and 50% by volume or less. The second porous layer has a void fraction greater than the void fraction of the first porous layer.

Abstract: According to one embodiment, an electrode is provided. A length of a first active material portion along a first direction is within a range of 0.7T or more and 0.95T or less with respect to a thickness T of an active material-containing layer. The first direction is parallel to a thickness direction. A second active material portion further contains solid electrolyte particles. A ratio E1/E2 is 0 or more and 0.01 or less. The ratio E1/E2 represents a ratio of a content E1 of the solid electrolyte particles per unit area in the first active material portion (including 0) to a content E2 of the solid electrolyte particles per unit area in the second active material portion.

Abstract: According to one embodiment, a nonaqueous electrolyte including an ionic liquid is provided. The ionic liquid includes: a cation including trialkyl sulfonium ions and lithium ions; a first anion of [N(FSO2)2]?; and a second anion including one or more selected from the group consisting of [N(CF3SO2)2]?, [N(FSO2)(CF3SO2)]?, [N(FSO2)(C2F5SO2)]?, [N(FSO2)(n-C4F9SO2)]?, PF6?, and BF4?. A molar ratio between the first anion and the second anion is in the range of 1:4 to 4:1. A molar ratio between the lithium ions and the trialkyl sulfonium ions is in the range of 1:4 to 4:1.

Abstract: According to one embodiment, an electrode is provided. The electrode includes an active material-containing layer. The active material-containing layer includes: an active material including a titanium-containing composite oxide; inorganic solid particles having lithium ion conductivity; and carbon fiber. The active material-containing layer has a first peak indicating a maximum log differential pore volume in a log differential pore volume distribution curve according to mercury porosimetry. A pore diameter PD at the first peak is 0.01 ?m to 0.1 ?m. The first peak has a full width at half maximum of 0.05 ?m or less.

Abstract: According to one embodiment, a storage battery includes one or more first batteries that include a first active material as a negative electrode active material, and one or more second batteries that include a second active material having an operation electric potential lower than that of the first active material as a negative electrode active material. Charge and the discharge of the second batteries are stopped based on a fact that a temperature of the storage battery is lower than a temperature threshold. The second batteries are caused to charge or discharge based on a fact that the temperature of the storage battery is equal to or higher than the temperature threshold.

Abstract: According to one embodiment, a secondary battery includes a positive electrode, a negative electrode, a nonaqueous electrolyte and a separator. The positive electrode includes a halide including at least one metal element selected from the group consisting of copper, iron, nickel, cobalt, tin, and zinc. The negative electrode includes at least one selected from the group consisting of lithium metal, a lithium alloy, and a compound capable of having Li inserted and extracted. The nonaqueous electrolyte includes an ionic liquid including chlorine ions. The separator has lithium ion conductivity, and is interposed between the positive electrode and the negative electrode.

Abstract: According to one embodiment, an electrode group includes a positive electrode active material-containing layer, a negative electrode active material-containing layer, a lithium ion conductive layer, and a porous layer. The lithium ion conductive layer includes lithium-containing inorganic particles. The lithium ion conductive layer covers at least part of the positive electrode active material-containing layer. The porous layer covers at least part of the negative electrode active material-containing layer. The positive electrode active material-containing layer and the negative electrode active material-containing layer face each other via the lithium ion conductive layer and the porous layer.

Abstract: According to one embodiment, there is provided an electrode group including an electrically insulating layer, a first electrode, and a second electrode. The second electrode is stacked in a first direction on the first electrode with the electrically insulating layer interposed therebetween. The first electrode includes plural first end portions in one or more second directions among directions orthogonal to the first direction. The plural first end portions are disposed at different positions in at least one of the second directions.

Abstract: According to one embodiment, an electrode is provided. The active material-containing layer includes an active material, inorganic solid particles having lithium ion conductivity, and carbon fiber. A pore diameter DM at the first peak is 0.05 ?m to 10 ?m. A value SA-SB is 1.4 or more in a slope distribution curve of the active material-containing layer, where a vertical axis of the slope distribution curve represents a slope of a straight line passing through two adjacent measurement points on the log differential pore volume distribution curve and a horizontal axis of the slope distribution curve represents a smaller pore diameter of the two adjacent measurement points. The value SA-SB is obtained by subtracting a minimum slope value SB from a maximum slope value SA.

Abstract: According to one embodiment, an electrode is provided. The electrode includes a current collector, a first layer formed on the current collector, and a second layer formed on at least part of the first layer. The first layer contains a monoclinic niobium titanium composite oxide. The second layer contains lithium titanate having a spinel structure. A porosity P2 of the second layer is within a range from 30% to 80%.

Abstract: According to one embodiment, an electrode is provided. The electrode includes an active material-containing layer. The active material-containing layer includes: an active material including a titanium-containing composite oxide; inorganic solid particles having lithium ion conductivity; and carbon fiber. The active material-containing layer has a first peak indicating a maximum log differential pore volume in a log differential pore volume distribution curve according to mercury porosimetry. A pore diameter PD at the first peak is 0.01 ?m to 0.1 ?m. The first peak has a full width at half maximum of 0.05 ?m or less.