Abstract: A method for forming a nanocomposite material, the nanocomposite material formed thereby, and a battery made using the nanocomposite material. Metal oxide and graphene are placed in a solvent to form a suspension. The suspension is then applied to a current collector. The solvent is then evaporated to form a nanocomposite material. The nanocomposite material is then electrochemically cycled to form a nanocomposite material of at least one metal oxide in electrical communication with at least one graphene layer.

Abstract: A secondary battery in which graphite that is an active material can occlude and release lithium efficiently is provided. Further, a highly reliable secondary battery in which the amount of lithium inserted and extracted into/from graphite that is an active material is prevented from varying is provided. The secondary battery includes a negative electrode including a current collector and graphite provided over the current collector, and a positive electrode. The graphite includes a plurality of graphene layers. Surfaces of the plurality of graphene layers are provided substantially along the direction of an electric field generated between the positive electrode and the negative electrode.

Abstract: A rechargeable battery including an electrode assembly including first and second electrode plates, each of which includes an electrode uncoated portion and a separator interposed between the first and second electrode plates, and at least one current collector plate, each current collector plate contacting one of the electrode uncoated portions of the first and second electrode plates, wherein each current collector plate includes a protrusion protruding toward the electrode assembly and having a contact portion contacting one of the electrode uncoated portions, and a slit in the contact portion disposed at a predetermined angle with respect to the direction of the electrode assembly.

Abstract: A lithium ion battery includes at least one battery cell. The battery cell includes a cathode electrode, an anode electrode, and a separator. The separator is sandwiched between the cathode electrode and the anode electrode. At least one of the cathode electrode and the anode electrode includes a current collector. The current collector is a graphene layer.

Abstract: To provide an electrolytic copper foil for a negative electrode for a lithium-ion secondary battery with which it is possible to produce a long-life lithium-ion secondary battery in which there is no decline in the capacity retention ratio even when the charge-discharge cycling is repeated, that has long life, and no deformation of a negative electrode current collector occurs. The electrolytic copper foil constituting the negative electrode current collector for the lithium-ion secondary battery has, after heat treatment at from 200 to 400° C., a 0.2% proof stress of 250N/mm2 or more, and elongation of 2.5% or more; and the surface on which an active material layer of the electrolytic copper foil is provided has been rust-proofed, or roughened and rust-proofed.

Abstract: A conductor foil for a negative electrode of a lithium-ion accumulator comprises at least one lithium-ion cell. The conductor foil comprises an aluminum foil both sides of which are covered by a metal layer consisting of copper or nickel. The disclosure further relates to a lithium-ion accumulator and to a motor vehicle comprising a lithium-ion accumulator.

Abstract: A lithium ion conductor represented by Formula 1: Li1+x+2yAlxMgyM2?x?y(PO4)3 ??Formula 1 wherein, in Formula 1, M includes at least one of titanium (Ti), germanium (Ge), zirconium (Zr), hafnium (Hf), and tin (Sn), 0<x<0.6, and 0<y<0.2.

Abstract: A current collector includes a support and at least one graphene layer located on the support. The support includes two surfaces. The at least one graphene layer is located on one of the two surfaces of the support. The at least one graphene layer includes a number of uniformly distributed graphenes.

Abstract: An electrode assembly and a lithium secondary battery comprising the same are disclosed. Specifically, the present invention provides an electrode assembly which is capable of preventing the occurrence of a short circuit between a non-coating portion of an electrode plate and an active material layer of an electrode plate having an opposite polarity when damage or shrinkage of a separator takes place, through the attachment of an insulating tape to either or both sides of the non-coating portion of an electrode plate without attachment of an electrode tab. Therefore, an internal short circuit of the battery can be prevented by application of the electrode assembly of the present invention to a variety of lithium secondary batteries including pouch-type, polygonal and cylindrical batteries.

Abstract: A battery includes a case defining an inner space, the case having an inner wall, an electrode assembly in the inner space, the electrode assembly including an uncoated region, a lead tab configured to carry electricity, the lead tab being connected to the uncoated region, and a retainer, the retainer being joined to the lead tab and disposed between the electrode assembly and the inner wall, the retainer having a predetermined thickness.

Abstract: An electrode for non-aqueous electrolyte secondary batteries includes a current collector having principal surfaces facing each other and an active material layer which contains an active material, a binder, and a conductive material and which is placed on at least one of the principal surfaces of the current collector. The sum of the volume of the active material per unit area of the current collector and the volume of the conductive material per unit area of the current collector is 9.70×10?2 cm3/cm2 to 24.6×10?2 cm3/cm2, the volume of the active material being calculated from the average particle size D50 of the active material, the volume of the conductive material being calculated from the average particle size D50 of the conductive material. The pore volume of the active material layer per unit area of the current collector is 6.00×10?3 cm3/cm2 to 20.0×10?3 cm3/cm2.

Abstract: The invention addresses the problem of providing a polyimide precursor, a polyimide precursor solution, and a mixture slurry, each capable of more firmly binding active material particles to a current collecting body. The polyimide precursor solution according to the invention contains a tetracarboxylic acid ester compound, a diamine compound having an anionic group, and a solvent. The solvent dissolves the tetracarboxylic acid ester compound and the diamine compound. As the tetracarboxylic acid ester compound, a 3,3?,4,4?-benzophenonetetracarboxylic acid diester is particularly preferred. Examples of the “diamine compound having an anionic group” include 3,4-diaminobenzoic acid, 3,5-diaminobenzoic acid, and m-phenylenediamine-4-sulfonic acid. Further, the mixture slurry according to the invention contains active material particles in the polyimide precursor solution.

Abstract: Lithium-manganese-containing molecular precursor compounds, compositions and processes for making cathodes for lithium ion batteries. The molecular precursor compounds are soluble and provide processes to make cathode materials with controlled stoichiometry in a solution-based processes. The cathode material can be, for example, a lithium manganese oxide, a lithium manganese phosphate, or a lithium manganese silicate. Cathodes can be made as bulk material in a solid form or in solution, or in various forms including thin films.

Abstract: An active material sheet includes an active material that stores charge, and a binder that binds the active material. The active material is granular and 90% or more of active material particles have a particle diameter equal to or less than 20 ?m. The active material particles include a first group of particles having a particle diameter equal to or less than 5 ?m and a circularity ranging from 0.850 to 1.000 and a second group of particles having a particle diameter greater than 5 ?m and equal to or less than 20 ?m and a circularity ranging from 0.500 to 0.850.

Abstract: A lithium-ion cell includes outgoing conductor foils and collectors. The outgoing conductor foil of a negative electrode of the lithium-ion cell consists of an aluminum foil which is covered on both sides with a metal layer. The collector for the negative electrode has an aluminum workpiece, which is at least partially covered with a metal layer. The metal layers of the outgoing conductor foil and of the collector consist of copper or nickel.

Abstract: Lithium-iron molecular precursor compounds, compositions and processes for making a cathode for lithium ion batteries. The molecular precursor compounds are soluble and provide processes to make stoichiometric cathode materials with solution-based processes. The cathode material can be, for example, a lithium iron oxide, a lithium iron phosphate, or a lithium iron silicate. Cathodes can be made as bulk material in a solid form or in solution, or in various forms including thin films.

Abstract: Lithium-cobalt-containing molecular precursor compounds, compositions and processes for making cathodes for lithium ion batteries. The molecular precursor compounds are soluble and provide processes to make stoichiometric cathode materials with solution-based processes. The cathode material can be, for example, a lithium cobalt oxide, a lithium cobalt phosphate, or a lithium cobalt silicate. Cathodes can be made as bulk material in a solid form or in solution, or in various forms including thin films.

Abstract: The present invention relates to a lithium ion battery employed by connecting the positive electrode side to a negative electrode portion made of Cu or a Cu alloy by a bus bar made of Al or an Al alloy and provides a negative electrode terminal for a lithium ion battery capable of providing sufficient bonding strength between the negative electrode portion and the bus bar when the negative electrode portion and the bus bar are metallurgically bonded to each other by resistance welding or the like, for example. This negative electrode terminal for a lithium ion battery is made of a clad material having a first metal layer made of Al or an Al alloy and a second metal layer made of Cu or a Cu alloy bonded to each other through a reaction-suppressing layer suppressing a reaction therebetween.

Abstract: A sodium-chalcogen cell is described which is operable at room temperature, in particular a sodium-sulfur or sodium-oxygen cell, the anode and cathode of which are separated by a solid electrolyte which is conductive for sodium ions and nonconductive for electrons. The cathode of the sodium-chalcogen cell includes a solid electrolyte which is conductive for sodium ions and electrons. Moreover, a manufacturing method for this type of sodium-chalcogen cell is described.

Abstract: High capacity energy storage devices and energy storage device components, and more specifically, to a system and method for fabricating such high capacity energy storage devices and storage device components using processes that form three-dimensional porous structures are provided. In one embodiment, an anode structure for use in a high capacity energy storage device, comprising a conductive collector substrate, a three-dimensional copper-tin-iron porous conductive matrix formed on one or more surfaces of the conductive collector substrate, comprising a plurality of meso-porous structures formed over the conductive current collector, and an anodically active material deposited over the three-dimensional copper-tin-iron porous conductive matrix is provided.

Abstract: Disclosed herein is a protection circuit module (PCM) including a protection circuit for controlling overcharge, overdischarge, and overcurrent of a battery, wherein a pair of connection members are attached to the bottom of the PCM, while the connection members are electrically connected to the protection circuit, the connection members being constructed by bending a sheet material into a predetermined shape, to form groove-shaped connection structures into which plate-shaped electrode terminals of a battery cell are inserted and coupled. Each of the connection members includes a lower connection plate, a pair of rear extensions, and front extensions.

Abstract: A lithium secondary battery with superior cycle performance is provided. The lithium secondary battery includes a negative electrode including a negative electrode active material layer disposed on a negative electrode current collector and containing negative electrode active material particles, negative electrode conductor particles, and a negative electrode hinder; a positive electrode containing a positive electrode active material; and a non-aqueous electrolyte. The concentration of the negative electrode conductor particles in a surface layer of the negative electrode active material layer facing away from the negative electrode current collector is higher than the concentration of the negative electrode conductor particles in a center of the negative electrode active material layer.

Abstract: To provide a slurry composition for a negative electrode of a lithium ion secondary cell, whereby a secondary cell having excellent cycle characteristics and output characteristics can be obtained, and whereby an electrode having excellent adhesion can be obtained. [Solution] This slurry composition for a negative electrode of a lithium ion secondary cell comprises a negative electrode active material, an aqueous dispersion binder, and water, and is characterized in that the specific surface area of the negative electrode active material is 3.0-20.0 m2/g, the aqueous dispersion binder is a polymer that contains dicarboxylic acid-containing monomer units and sulfonic acid-containing monomer units, the content ratio of dicarboxylic acid-containing monomer units in the polymer is 2-10% by mass, the content ratio of sulfonic acid-containing monomer units is 0.1-1.5% by mass, and the potassium ion content in the slurry composition is no more than 1000 ppm with respect to 100% by mass of the slurry composition.

Abstract: A method for manufacturing an active material, capable of improving the discharge capacity of a lithium ion secondary battery is provided. The method for manufacturing an active material according to the present invention includes a first step of heating a mixture solution including a lithium source, a phosphate source, a vanadium source, and water under pressure to generate a precursor in the mixture solution, and adjusting the pH of the mixture solution including the precursor to be 6 to 8; and a second step of heating the precursor at 425 to 650° C. after the first step to generate an active material.

Abstract: An exothermic component has a reactive multilayer arranged in grid-shape fashion on a carrier. The exothermic component can be incorporated in an electrode construction of a galvanic cell comprising electrode layers, a separator layer and current collecting layers. In addition, a matrix-like sensor arrangement can be provided in the electrode construction. Defect locations in the electrode construction can be identified on the basis of output signals of the sensor arrangement. By igniting selected regions of the reactive multilayer grid, which react exothermically, it is possible to destroy the defect locations in a targeted manner.

Abstract: The purpose of this invention is to provide an aluminum base for a current collector, which enables the production of a secondary battery having excellent cycle properties; and a current collector, a positive electrode, a negative electrode and a secondary battery, each of which is produced using the aluminum base. The aluminum base for a current collector has a surface in which at least two structures selected from the group consisting of a large-wave structure having an average opening size of more than 5 ?m but up to 100 ?m, a medium-wave structure having an average opening size of more than 0.5 ?m but up to 5 ?m, and a small-wave structure having an average opening size of more than 0.01 ?m but up to 0.5 ?m are superimposed on one another, wherein a maximum peak-to-valley height Pt of a profile curve of the surface is up to 10 ?m.

Abstract: A non-aqueous electrolyte secondary battery includes an electrode body including a positive electrode and a negative electrode superimposed upon each other with a separator interposed therebetween. The negative electrode is superimposed upon the positive electrode in a state where a negative electrode active material layer, except the part on a proximal end part of a negative electrode tab, is positioned inside an outer edge of a positive electrode active material layer of the positive electrode. A width H1 of the negative electrode active material layer including the part on the proximal end part of the negative electrode tab, width H2 of the negative electrode active material layer or negative electrode current collector at a part other than the negative electrode tab, and width H3 of the positive electrode active material layer are formed to satisfy the relationships of H2<H3, and (H1?H2)?(H3?H2)÷2.

Abstract: An active material capable of improving the discharge capacity of a lithium ion secondary battery is provided. The active material of the present invention includes LiVOPO4 and one or more metal elements selected from the group consisting of Al, Nb, Ag, Mg, Mn, Fe, Zr, Na, K, B, Cr, Co, Ni, Cu, Zn, Si, Be, Ti, and Mo.

Abstract: A secondary battery includes: a case; an electrode assembly housed in the case and including a first electrode, a second electrode, and a separator between the first electrode and the second electrode, the first electrode having a coating portion coated with a first active material and a non-coating portion absent the first active material; and a collector plate including first and second collector plates enmeshed together with the non-coating portion therebetween.

Abstract: Provided are examples of electrochemically active electrode materials, electrodes using such materials, and methods of manufacturing such electrodes. Electrochemically active electrode materials may include a high surface area template containing a metal silicide and a layer of high capacity active material deposited over the template. The template may serve as a mechanical support for the active material and/or an electrical conductor between the active material and, for example, a substrate. Due to the high surface area of the template, even a thin layer of the active material can provide sufficient active material loading and corresponding battery capacity. As such, a thickness of the layer may be maintained below the fracture threshold of the active material used and preserve its structural integrity during battery cycling.

Abstract: The invention pertains to the technical field of a Li-ion battery, in particular to a Li-ion battery positive plate structure, comprising a current collector, a base diaphragm arranged on the surface of the current collector and a top diaphragm arranged on the surface of the base diaphragm; both the base diaphragm and the top diaphragm respectively comprise an active substance, an adhesive and a conductive additive, wherein, the active substance of the base diaphragm is graphite, while the active substance of the top diaphragm is at least one among silicon, silicon alloy and tin alloy. Compared with the prior art, the Li-ion battery positive plate structure of the invention successfully solves the problem of film removal of silicon anode and alloy anode due to swelling in the process of charging because a graphite anode base diaphragm with buffering function is installed between the top diaphragm with swelling trend.

Abstract: A lithium ion secondary battery containing a pair of electrodes facing each other, and a separator interposed between the electrodes, wherein at least one of the electrodes has a protecting layer, an active-material containing layer, and a collector sequentially from the separator. The protecting layer contains a silicone resin particle having at least one structural unit represented by RSiO1.5 and R2SiO, where R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Abstract: A battery on a conductive metal wire and components of a battery on a conductive metal wire of circular cross section diameter of 5-500 micrometers and methods of making the battery and battery components are disclosed. In one embodiment, the battery features a porous anode or cathode layer which assist with ion exchange in batteries. Methods of forming the porous anode or cathode layer include deposition of an inert gas or hydrogen enriched carbon or silicon layer on a heated metal wire followed by annealing of the inert gas or hydrogen enriched carbon silicon layer. Energy storage devices having bundles of batteries on wires are also disclosed as are other energy storage devices.

Abstract: A battery comprises a battery case forming a substantially sealed enclosure and an electrode stack within the enclosure. The electrode stack includes a first set of electrode elements and a second set of electrode elements. The electrode elements in the second set alternate with the electrode elements in the first set within the electrode stack. In addition, the electrode elements include coincident alignment apertures. The coincident alignment apertures are configured to restrict rotation of the electrode elements to align the electrode elements when the alignment apertures are positioned over mating alignment protrusions during assembly of the electrode stack. The battery further comprises a feedthrough including a feedthrough pin extending through the battery case. The feedthrough pin is electrically coupled to the electrode stack and serves as a positive terminal for the battery.

Abstract: To provide a method for forming a storage battery electrode including an active material layer with high density in which the proportion of conductive additive is low and the proportion of the active material is high. To provide a storage battery having a higher capacity per unit volume of an electrode with the use of a storage battery electrode formed by the formation method. A method for forming a storage battery electrode includes the steps of forming a mixture including an active material, graphene oxide, and a binder; providing a mixture over a current collector; and immersing the mixture provided over the current collector in a polar solvent containing a reducer, so that the graphene oxide is reduced.

Abstract: An object of the present invention is to provide a negative-electrode mixture material for secondary battery that is excellent in terms of high-rate characteristics, and a negative electrode, as well as a secondary battery. A negative-electrode mixture material for secondary battery according to the present invention contains a negative-electrode active material including: a silicon elementary substance and a silicon compound; graphite; and a polyamide-imide/silica hybrid resin being made by bonding an alkoxysilyl group onto a polyamide-imide resin.

Abstract: Provided is a nonaqueous electrolyte secondary battery with improved high-rate discharge characteristics. The nonaqueous electrolyte secondary battery includes a positive electrode including a metal foil and a positive electrode active material layer formed thereon; a negative electrode containing a negative electrode active material; and a nonaqueous electrolyte containing a nonaqueous solvent and a solute dissolved therein. The metal foil of the positive electrode is an aluminum foil having an at least partially roughened surface adjacent to the positive electrode active material layer. The positive electrode includes a conductive layer containing a conductor and a binder in recesses in the at least partially roughened surface of the aluminum foil. The positive electrode active material layer is disposed on the conductive layer and contains a positive electrode active material, the conductor, and the binder.

Abstract: An object of the present invention is to provide a positive electrode for a nonaqueous electrolyte secondary battery capable of significantly improving cycling characteristics while decreasing production cost, a method for producing the positive electrode, and a nonaqueous electrolyte secondary battery using the positive electrode. The positive electrode includes a positive-electrode current collector, and a positive-electrode mixture layer formed on at least one of the surfaces of the positive-electrode current collector, wherein the positive-electrode mixture layer contains a positive electrode active material, a binder, a conductive agent, and at least one compound selected from the compound group consisting of rare earth acetic acid compounds, rare earth nitric acid compounds, and rare earth sulfuric acid compounds.

Abstract: Provided are a battery electrode with low internal resistance and a battery with high charge and discharge efficiency. The battery electrode includes a current collector formed of a porous metal having a three-dimensional network structure and an active material, and the active material is supported in the network structure of the current collector without using a binder resin.

Abstract: A rechargeable lithium cell comprising: (a) an anode comprising a prelithiated lithium storage material or a combination of a lithium storage material and a lithium ion source; (b) a hybrid cathode active material composed of a meso-porous structure of a carbon, graphite, metal, or conductive polymer and a phthalocyanine compound, wherein the meso-porous structure is in an amount of from 1% to 99% by weight based on the total weight of the meso-porous structure and the phthalocyanine combined, and wherein the meso-porous structure has a pore with a size from 2 nm to 50 nm to accommodate phthalocyanine compound therein; and (c) an electrolyte or electrolyte/separator assembly. This secondary cell exhibits a long cycle life and the best cathode specific capacity and best cell-level specific energy of all rechargeable lithium-ion cells ever reported.

Abstract: In an electrode according to the present invention including a three-dimensional network aluminum porous body as a base material, the electrode is a sheet-shaped electrode, and a cell of the three-dimensional network aluminum porous body has an elliptic shape having a minor axis in the thickness direction of the electrode in a cross section parallel to the longitudinal direction and thickness direction of the electrode, and a cell of the three-dimensional network aluminum porous body has an elliptic shape having a minor axis in the thickness direction of the electrode in a cross section parallel to the width direction and thickness direction of the electrode. The electrode is preferably obtained by subjecting the three-dimensional network aluminum porous body to at least a current collecting lead welding step, an active material filling step and a compressing step.

Abstract: Composite particles include a core comprising a layered lithium metal oxide having an O3 crystal structure. A shell layer having an O3 crystal structure encloses the core. The shell layer includes an oxygen-loss, layered lithium metal oxide. The core comprises from 30 to 85 mole percent of the composite particles. A cathode and a lithium-ion battery including the composite particles, and methods of making the foregoing are also disclosed.

Abstract: A energy storage device includes: an electrode assembly that includes a positive electrode plate and a negative electrode plate, the positive electrode plate and the negative electrode plate being mutually insulated; a case that houses the electrode assembly; and a conductive member electrically coupled to the electrode assembly in the case. The conductive member includes a main body part that has a central axis in a direction passing through a wall surface of the case, and a conductive connection part that protrudes from the main body part in a direction intersecting with the central axis. The main body part includes a swage portion disposed at one end portion of the main body part and inserted into the wall surface of case, and a non-circular head disposed at another end portion of the main body part.

Abstract: A cathode foil for a solid electrolytic capacitor is designed to increase capacitance, reduce ESR and leakage current, enhance heat resistance, and reduce production costs, while enhancing a power density, realizing rapid charging-discharging, and improving a life property, in an electric energy storage element such as a secondary battery, an electric double layer capacitor and a hybrid capacitor. A cathode foil or a current collector may include a metal foil, a metal layer, a mixed layer containing carbon and a substance composing the metal layer in a mixed state, and a carbon layer consisting substantially of carbon, each formed on the metal foil. The mixed layer is configured to have a composition changing from a state containing substantially only the substance composing the metal layer to a state containing substantially only carbon, in a direction from the metal layer to the carbon layer.

Abstract: The porous membrane according to the present invention comprises non-conductive particles, a binder, and a water-soluble polymer, and is characterized in that: the three dimensions of the non-conductive particles, namely the length (L), thickness (t), and width (b), are such that the length (L) is 0.1 to 0 ?m, the ratio (b/t) of the width (b) and the thickness (t) is 1.5 to 100; the binder is a copolymer containing (meth)acrylonitrile monomer units and (meth)acrylic acid ester monomer units; and the water-soluble polymer contains sulfonic acid groups, and has a weight average molecular weight of 1000 to 15000. The slurry for a porous membrane according to the present invention is characterized by being formed by dispersing the non-conductive particles, the binder, and the soluble polymer, in water.

Abstract: A lithium-ion secondary battery is provided which has a positive electrode formed using a composition formed of an aqueous solvent and which exhibits superior battery performance. The battery comprises a positive electrode and a negative electrode, and the positive electrode has a positive electrode current collector and a positive electrode mixture layer which is formed on the current collector and which includes at least a positive electrode active material and a hinder. A surface of the positive electrode active material is coated by a hydrophobic coating and the binder dissolves or disperses in the aqueous solvent.

Abstract: Disclosed herein is a cathode active material for secondary batteries and a secondary battery including the same, the cathode active material including lithium manganese oxide (A) having a spinel crystal structure and at least two types of lithium nickel-manganese-cobalt composite oxides (B) containing Ni, Mn, and Co as transition metals, wherein the lithium nickel-manganese-cobalt composite oxides (B) are different from each other in terms of at least one selected from the group consisting of elemental composition, particle diameter, and density.

Abstract: According to one embodiment, a positive electrode includes a positive electrode material layer and a positive electrode current collector. The positive electrode material layer includes a positive electrode active material having a composition represented by a formula (1) described below. The positive electrode material layer satisfies a formula (2) described below. The positive electrode material layer is formed on the positive electrode current collector.

Abstract: An electrode lead is applied as a part of at least one of a cathode lead and an anode lead of a secondary battery and includes a first metal plate and a second metal plate spaced apart from each other with a gap therebetween and having coating layers formed on the surfaces thereof except for surfaces of end portions thereof facing each others, and a metal bridge made of material having a lower melting point than the first metal plate and the second metal plate and buried in the gap so that the end portions are not exposed. In this case, if an overcurrent flows through the electrode lead, a portion of the metal plate at which a metal bridge is formed is rapidly broken to irreversibly interrupt the overcurrent flowing at the secondary battery without giving a substantial influence on the temperature of the secondary battery.

Abstract: A decomposition reaction of an electrolyte solution and the like caused as a side reaction of charge and discharge is minimized in repeated charge and discharge of a lithium ion battery or a lithium ion capacitor, and thus the lithium ion battery or the lithium ion capacitor can have long-term cycle performance. A negative electrode for a power storage device includes a negative electrode current collector and a negative electrode active material layer which includes a plurality of particles of a negative electrode active material. Each of the particles of the negative electrode active material has an inorganic compound film containing a first inorganic compound on part of its surface. The negative electrode active material layer has a film in contact with an exposed part of the negative electrode active material and part of the inorganic compound film. The film contains an organic compound and a second inorganic compound.