Abstract: A small capacity battery for powering electronic devices, such as an e-book reader, is provided. This small capacity battery is designed to produce low area-specific resistance, which maintains usable operating voltages even during periods of high current draw. As a result, a lighter and smaller form-factor battery may provide the same battery capacity as a larger and heavier conventional battery. A user may then be provided with a lightweight and small form-factor electronic device that achieves an extended battery life.

Abstract: A graphite material for a negative electrode of a lithium-ion secondary battery is provided. A ratio Lc(112)/Lc(006) defined as a ratio of expansion of graphene sheets to sheet displacement ranges from 0.08 to 0.11, both inclusive. A crystallite size Lc(006) calculated from a wide-angle X-ray diffraction line ranges from 30 nm to 40 nm, both inclusive. An average particle size ranges from 3 ?m to 20 ?m, both inclusive.

Abstract: Provided are battery electrode structures that maintain high mass loadings (i.e., large amounts per unit area) of high capacity active materials in the electrodes without deteriorating their cycling performance. These mass loading levels correspond to capacities per electrode unit area that are suitable for commercial electrodes even though the active materials are kept thin and generally below their fracture limits. A battery electrode structure may include multiple template layers. An initial template layer may include nanostructures attached to a substrate and have a controlled density. This initial layer may be formed using a controlled thickness source material layer provided, for example, on a substantially inert substrate. Additional one or more template layers are then formed over the initial layer resulting in a multilayer template structure with specific characteristics, such as a surface area, thickness, and porosity.

Abstract: An energy storage device includes a nano-structured cathode. The cathode includes a conductive substrate, an underframe and an active layer. The underframe includes structures such as nano-filaments and/or aerogel. The active layer optionally includes a catalyst disposed within the active layer, the catalyst being configured to catalyze the dissociation of cathode active material.

Abstract: A method of operating a lithium-ion cell comprising (a) a cathode comprising a carbon or graphitic material having a surface area to capture and store lithium thereon; (b) an anode comprising an anode active material; (c) a porous separator disposed between the two electrodes; (d) an electrolyte in ionic contact with the two electrodes; and (e) a lithium source disposed in at least one of the two electrodes to obtain an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made; wherein the method comprises: (A) electrochemically forming the cell from the OCV to either a first lower voltage limit (LVL) or a first upper voltage limit (UVL), wherein the first LVL is no lower than 0.1 volts and the first UVL is no higher than 4.6 volts; and (B) cycling the cell between a second LVL and a second UVL.

Abstract: A method of fabricating a multilayered thin film solid state battery device. The method steps include, but are not limited to, the forming of the following layers: substrate member, a barrier material, a first electrode material, a thickness of cathode material, an electrolyte, an anode material, and a second electrode material. The formation of the barrier material can include forming a polymer material being configured to substantially block a migration of an active metal species to the substrate member, and being characterized by a barrier degrading temperature. The formation of cathode material can include forming a cathode material having an amorphous characteristic, while maintaining a temperature of about ?40 Degrees Celsius to no greater than 500 Degrees Celsius such that a spatial volume is characterized by an external border region of the cathode material. The method can then involve transferring the resulting thin film solid state battery device.

Abstract: The present invention relates to a silicon-based composite including a silicon oxide which is coated thereon with carbon and bonded therein to lithium. The present invention also relates to a method of producing a silicon-based composite, comprising coating a surface of silicon oxide with carbon, mixing the silicon oxide coated with carbon with lithium oxide, and heat-treating a mixture of the silicon oxide coated with carbon and the lithium oxide in an inert atmosphere.

Abstract: An object of the present invention is to provide a material for non-aqueous electrolyte secondary battery negative electrodes containing a graphitic material and a non-graphitizable carbonaceous material, the material having excellent resistance against deterioration due to moisture absorption and excellent charge/discharge cycle resistance; a non-aqueous electrolyte secondary battery negative electrode using the same; and a non-aqueous electrolyte secondary battery using these, that has low resistance and excellent cycle durability. The present invention comprises a carbonaceous material obtained by carbonizing a plant-derived organic material having a potassium content of 0.5% by mass or less, an average particle size Dv50 of 2 ?m to 50 ?m, an average interlayer spacing of (002) plane determined by powder X-ray diffraction of 0.365 nm to 0.400 nm, an atomic ratio (H/C) of hydrogen atoms to carbon atoms determined by elemental analysis of 0.

Abstract: An electrode material for a lithium-ion battery comprises a porous agglomeration of particles, the particles being formed from nanopowder of a transition metal oxide and comprising cores of stoichiometric transition metal oxide surrounded by under stoichiometric oxide of the transition metal. Also described and claimed are the use of a corresponding material in a lithium ion battery and a method of making such an electrode.

Abstract: A method for modifying graphite particles having a prismatic shape or a cylindrical shape characterized by an edge function fe and a basal function fb, said method providing increase of the edge function and lowering of the basal function, wherein the method includes submitting the graphite particles to at least one physical means selected from attrition, jet mill, ball mill, hammer mill, or atomizer mill, in the presence of at least one chemical compound chosen from the group of compounds of the formula MFz, in which M represents an alkaline or alkaline-earth metal and z represents 1 or 2, NaCl and NH4F or a mixture thereof, said compound or compounds being added in solid form, at the beginning of the step using the physical means.

Abstract: An electrode for a lithium secondary battery includes an electrode active material, a conductive agent, and a polyurethane-based compound, and has pores having an average diameter of about 2 to about 20 nm. A lithium secondary battery includes the electrode.

Abstract: A secondary particle and a lithium battery including the same are provided wherein the secondary particle includes a plurality of primary particles and each primary particle contains n polycyclic nano-sheets disposed upon one another. The polycyclic nano-sheets include hexagonal rings of six carbon atoms linked to each other, wherein a first carbon and a second carbon have a distance therebetween of L1. L2 is a distance between a third carbon and a fourth carbon, and the arrangement of the polycyclic nano-sheets is such that L1?L2. The secondary particle is used as a negative active material in the lithium battery, and the secondary particle contains pores, thereby allowing for effective intercalating and deintercalating of the lithium ions into the secondary particle to impart improved capacity and cycle lifespan.

Abstract: A known method for producing a porous carbon product comprises producing a monolithic template from inorganic matrix material having pores connected to each other, infiltrating the pores of the template with carbon or a carbon precursor substance forming a green body framework containing carbon surrounded by matrix material and calcining the green body framework forming the porous carbon product. In order to provide a method proceeding herefrom which permits cost-effective production of a product from porous carbon, according to the invention the production of the template comprises a soot separation process in which a hydrolyzable or oxidable starting compound of the matrix material is supplied to a reaction zone, therein converted to matrix material particles by hydrolysis or pyrolysis, the matrix material particles are agglomerated or aggregated and formed to the template.

Abstract: A coating on an anode active material that includes a metal salt with two or more sulfonates or a metal salt of oxocarbonic acid.

Abstract: Electrochemical capacitors and methods for producing such electrochemical capacitors. The electrochemical capacitor can have an initial charged state and a cycled charged state and can include an anode, a cathode, and an electrolyte. The anode can include a first mixture having a first plurality of electrically conductive carbon-comprising particles having a first average porosity. The cathode can include a second mixture having a second plurality of electrically conductive carbon-comprising particles having a second average porosity greater than said first average porosity. The electrolyte can be physically and electrically contacting said anode and said cathode, and the first mixture in the cycled charged state can be substantially free of lithium metal particles and can further include a plurality of lithium ions intercalating the first plurality of carbon comprising particles. The mass ratio of the cathode and the electrolyte can be less than 1.

Abstract: Porous electrodes in which the porosity has a low tortuosity are generally provided. In some embodiments, the porous electrodes can be designed to be filled with electrolyte and used in batteries, and can include low tortuosity in the primary direction of ion transport during charge and discharge of the battery. In some embodiments, the electrodes can have a high volume fraction of electrode active material (i.e., low porosity). The attributes outlined above can allow the electrodes to be fabricated with a higher energy density, higher capacity per unit area of electrode (mAh/cm2), and greater thickness than comparable electrodes while still providing high utilization of the active material in the battery during use. Accordingly, the electrodes can be used to produce batteries with high energy densities, high power, or both compared to batteries using electrodes of conventional design with relatively highly tortuous pores.

Abstract: A negative active material including: a composite including a matrix comprising silicon oxide, silicon carbide, and carbon and silicon particles dispersed in the matrix; and a carbon coating film formed on a surface of the composite, wherein an intensity ratio of a SiC peak to a Si peak in an X-ray diffraction spectrum is 1 or more, a method of preparing the negative active material, a negative electrode including the negative active material, and a lithium battery including the electrode.

Abstract: There is provided an energy storage device including an electrode assembly having a pair of electrodes overlapped with each other. At least one of the electrodes includes a current collecting substrate, an active material layer arranged on the current collecting substrate, an intermediate layer arranged between the current collecting substrate and the active material layer, and an insulating layer arranged on the current collecting substrate. The active material layer contains an active material and a first binder. The intermediate layer contains a carbonaceous material and a second binder. The insulating layer contains an insulating material and a third binder. The second binder is a nonaqueous binder. The third binder is an aqueous binder.

Abstract: A negative electrode 1 for lithium secondary batteries, which can increase the charge/discharge capacity of a lithium secondary battery, includes a negative electrode current collector, a negative electrode active material layer, and a lithium layer. The negative electrode active material layer is disposed on regions and of the respective surfaces and of the negative electrode current collector. The lithium layer is disposed on uncovered regions and, which are regions of the respective surfaces and of the negative electrode current collector on which the negative electrode active material layer is not disposed. The lithium layer includes lithium.

Abstract: A graphite material for a negative electrode of a lithium-ion secondary battery is provided. A ratio Lc(112)/Lc(006) defined as a ratio of expansion of graphene sheets to sheet displacement ranges from 0.08 to 0.11, both inclusive. A crystallite size Lc(006) calculated from a wide-angle X-ray diffraction line ranges from 30 nm to 40 nm, both inclusive. An average particle size ranges from 3 ?m to 20 ?m, both inclusive.

Abstract: A negative electrode active material layer composition for a rechargeable lithium battery is disclosed. The negative electrode active material layer composition includes a negative active material including Li-doped SiOx (0<x<2), an aqueous binder, and pure water. In addition, a method of manufacturing the negative electrode active material layer composition, and a negative electrode and a rechargeable lithium battery including the same are also disclosed.

Abstract: A rechargeable lithium battery including a negative electrode, the negative electrode including a silicon-based material and graphite; a positive electrode; and an electrolyte, wherein the negative electrode includes silicon in an amount of greater than 0 wt % and less than or equal to about 2 wt %, based on a total weight of the silicon-based material and the graphite, and the rechargeable lithium battery has a discharge cut-off voltage of greater than or equal to about 3.1 V.

Abstract: In order to propose a new negative electrode for nonaqueous electrolyte secondary batteries having excellent dispersibility even with a negative electrode active material having a relatively small particle size, there is proposed a negative electrode active material for nonaqueous electrolyte secondary batteries, the negative electrode active material containing silicon and having negative electrode active material particles that have a D50 based on a volume-based particle size distribution obtainable by measurement by a laser diffraction scattering type particle size distribution analysis method, of 0.1 ?m to 5.0 ?m, and include a surface layer containing oxygen, silicon and carbon on the entire surface or a portion of the active material surface.

Abstract: Conventionally, there is a problem that a volume of a negative electrode active material changes during a charge-discharge cycle, a conductive network in a negative electrode gradually degrades, and thus a capacity of the negative electrode decreases. To solve the problem, the present invention has an object to prevent a reduction in capacity of the negative electrode, and increase life of a lithium ion secondary battery. A negative electrode active material for lithium ion secondary battery includes: a graphite core material; and a covering layer that covers a surface of the core material, wherein the covering layer has a thickness of 1 nm to 200 nm, and has a bulk modulus lower than a bulk modulus of the core material.

Abstract: Disclosed is a nonaqueous secondary battery (100) comprising a positive electrode (155) having a positive current collector (151) made of a metal, and a positive electrode active material (153) composed of a lithium-metal complex oxide. The surface of the positive electrode active material (153) is coated with a lithium salt (158) having an average thickness of 20-50 nm.

Abstract: The present invention relates to a negative electrode material for secondary batteries, comprising graphite; wherein the graphite comprises hexagonal crystal graphite and rhombohedral crystal graphite, and has a low-crystalline carbon coating on a surface thereof; and the graphite has exothermic peaks in the range of 600° C. or lower and in the range of 690° C. or higher in DTA measurement, or the graphite has a full width at half maximum of a (101) peak of the hexagonal crystal graphite of 0.2575° or less in XRD measurement, or the graphite has an absolute value of the difference between the lattice strain obtained from (101) plane spacing of the hexagonal crystal graphite and the lattice strain obtained from (100) plane spacing of the hexagonal crystal graphite of 7.1×10?4 or less in XRD measurement.

Abstract: An electrode material of the present invention includes surface-coated LixAyDzPO4 particles obtained by coating surfaces of LixAyDzPO4 (in which, A represents one or more selected from the group consisting of Co, Mn, Ni, Fe, Cu and Cr, D represents one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y and rare earth elements, 0<x?2, 0<y?1, and 0?z?1.5) particles with a carbonaceous coat, and an elution amount of Li is in a range of 200 ppm to 700 ppm and an elution amount of P is in a range of 500 ppm to 2000 ppm when the surface-coated LixAyDzPO4 particles are immersed in a sulfuric acid solution having a hydrogen-ion exponent of 4 for 24 hours.

Abstract: Highly dispersed lithium titanate crystal structures having a thickness of few atomic layers level and the two-dimensional surface in a plate form are supported on carbon nanofiber (CNF). The lithium titanate crystal structure precursors and CNF that supports these are prepared by a mechanochemical reaction that applies sheer stress and centrifugal force to a reactant in a rotating reactor. The mass ratio between the lithium titanate crystal structure and carbon nanofiber is preferably between 75:25 and 85:15. The carbon nanofiber preferably has an external diameter of 10-30 nm and an external specific surface area of 150-350 cm2/g. This composite is mixed with a binder and then molded to obtain an electrode, and this electrode is employed for an electrochemical element.

Abstract: Surface-modified carbon hybrid particles may be characterized by a high surface area and a high mesopore content. Surface-modified carbon hybrid particles may be in agglomerated form. Surface-modified carbon hybrid particles may be used, for example, as conductive additives. Dispersions of such compounds in a liquid medium in the presence of a surfactant may be used, for example, as conductive coatings. Polymer compounds filled with the surface-modified carbon hybrid particles may be formed. Surface-modified carbon hybrid particles may be used, for example, as carbon supports.

Abstract: An improved lithium-sulfur battery containing a surface-functionalized carbonaceous material. The presence of the surface-functionalized carbonaceous material generates weak chemical bonds between the functional groups of the surface-functionalized carbonaceous material and the functional groups of the polysulfides, which prevents the polysulfide migration to the battery anode, thereby providing a battery with relatively high energy density and good partial discharge efficiency.

Abstract: An object of the present invention is to provide a lithium ion battery which is excellent in properties at large current and can be applied to applications requiring high output power even when the mixture layers are made thick. The present invention provides a lithium ion battery including a positive electrode including a positive electrode mixture layer formed on a current collector, a negative electrode including a negative electrode mixture layer formed on a current collector and an electrolyte, the positive electrode and the negative electrode being disposed through the intermediary of a separator, wherein the positive electrode includes as a positive electrode active material a lithium composite oxide represented by LiNiaMnbCOcMdO2 (in the formula, M is at least one selected from the group consisting of Fe, V, Ti, Cu, Al, Sn, Zn, Mg, B and W, a+b+c+d=1, 0.2?a?0.8, 0.1?b?0.4, 0?c?0.4 and 0?d?0.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, and an electrolyte. The negative electrode includes a current collector, an active material layer on the current collector and including an amorphous silicon oxide represented by SiOx (0.95<x<1.7), and an SEI layer on the active material layer and including about 70 area % or more of protrusion parts having a size of about 5 nm to 300 nm during charging of the battery.

Abstract: The present invention is a secondary battery having a high specific capacity and good cycleability, and that can be used safely. The secondary battery is manufactured to include an anode formed from a host material capable of absorbing and desorbing lithium in an electrochemical system such as a carbonaceous material, and lithium metal dispersed in the host material. The anodes of the invention are combined with a cathode including an active material, a separator that a separates the cathode and the anode, and an electrolyte in communication with the cathode and the anode. The present invention also includes a method of preparing an anode and a method of operating a secondary battery including the anode of the invention.

Abstract: Dry process based energy storage device structures and methods for using a dry adhesive therein are disclosed.

Abstract: Disclosed is a method for preparing an anode active material comprising a core composed of a crystalline carbon-based material, and a composite coating layer comprising (a) mixing a precursor for a raw material of one or more materials selected from the group consisting of low crystalline carbon and amorphous carbon with silicon oxide enabling intercalation and deintercalation of ions, followed by purification, to prepare a mixture for coating, (b) mixing the mixture for coating with a crystalline carbon-based material to prepare a core-shell precursor comprising the raw material mixture for coating applied to the core composed of the crystalline carbon-based material, and (c) baking the core-shell precursor to carbonize the raw material of the one or more materials selected from the group consisting of low crystalline carbon and amorphous carbon into the one or more materials selected from the group consisting of low crystalline carbon and amorphous carbon.

Abstract: A powder comprises a plurality of carbon nanostructures, with at least a portion of the carbon nanostructures defining an internal cavity that contains metallic lithium, a lithium compound, or a lithium alloy comprising lithium. A method of forming the powder involves the electrolytic disintegration of a graphite electrode in a lithium-bearing molten salt to form the carbon nanostructures, and a step of removing salt from the nanoparticles without removing lithium. A lithium battery anode comprising an anode comprising the powder as a layer on an electrically conductive substrate.

Abstract: An isolated salt comprising a compound of formula (H2X)(TiO(Y)2) or a hydrate thereof, wherein X is 1,4-diazabicyclo[2.2.2]octane (DABCO), and Y is oxalate anion (C2O4?2), when heated in an oxygen-containing atmosphere at a temperature in the range of at least about 275° C. to less than about 400° C., decomposes to form an amorphous titania/carbon composite material comprising about 40 to about 50 percent by weight titania and about 50 to about 60 percent by weight of a carbonaceous material coating the titania. Heating the composite material at a temperature of about 400 to 500° C. crystallizes the titania component to anatase. The titania materials of the invention are useful as components of the cathode or anode of a lithium or lithium ion electrochemical cell.

Abstract: There is provided a positive-electrode material for a lithium secondary battery. The material comprises a lithium oxide compound or a complex oxide as reactive substance. The material also comprises at least one type of carbon material, and optionally a binder. A first type of carbon material is provided as a coating on the reactive substance particles surface. A second type of carbon material is carbon black. And a third type of carbon material is a fibrous carbon material provided as a mixture of at least two types of fibrous carbon material different in fiber diameter and/or fiber length. Also, there is provided a method for preparing the material as well as lithium secondary batteries comprising the material.

Abstract: An all-solid-state cell contains at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, which are arranged in a stack. The positive electrode layer contains only a positive electrode active material, and a predetermined crystal plane of the positive electrode active material is oriented in a direction of lithium ion conduction. The negative electrode layer contains a carbonaceous material, and the volume ratio of the carbonaceous material to the negative electrode layer is 70% or greater.

Abstract: Nano-colloids of near monodisperse, carbon-coated SnO2 nano-colloids. There are also carbon-coated SnO2 nanoparticles. There are also SnO2/carbon composite hollow spheres as well as an anode of a Li-ion battery having the nano-colloids. There is also a method for synthesizing SnO2 nano-colloids. There are also coaxial SnO2@carbon hollow nanospheres, a method for making coaxial SnO2@carbon hollow nanospheres and an anode of a Li-ion battery formed from the coaxial SnO2@carbon hollow nanospheres.

Abstract: An electric storage device includes a negative electrode, a positive electrode, and a separator interposed between the negative electrode and the positive electrode, the negative electrode including a negative electrode layer including an active material including an amorphous carbon particle capable of occluding and releasing at least one of an alkali metal and an alkaline earth metal, and a binder. The negative electrode layer includes a plurality of pores, and a ratio S1/S2 of a specific surface area (S1) of micropores having a pore diameter of 1 nm or more and 3 nm or less in the pores to a specific surface area (S2) of mesopores having a pore diameter of 20 nm or more and 100 nm or less therein is 0.3 or more and 0.9 or less.

Abstract: The present disclosure provides a sheet-form electrode for a secondary battery, comprising a current collector; an electrode active material layer formed on one surface of the current collector; a conductive layer formed on the electrode active material layer and comprising a conductive material and a binder; and a first porous supporting layer formed on the conductive layer. The sheet-form electrode for a secondary battery according to the present disclosure has supporting layers on at least one surfaces thereof to exhibit surprisingly improved flexibility and prevent the release of the electrode active material layer from a current collector even if intense external forces are applied to the electrode, thereby preventing the decrease of battery capacity and improving the cycle life characteristic of the battery.

Abstract: A carbon material for lithium ion secondary batteries of the invention contains amorphous carbon and graphite. The amorphous carbon is deposited on a surface of the graphite, the amorphous carbon content is 55% by weight to 99% by weight, and the graphite content is 1% by weight to 45% by weight.

Abstract: The present invention relates to an anode active material for a lithium-polymer battery having high capacity and high rapid charge/discharge characteristics, and a lithium-polymer battery using the same, and more specifically, to: a non-carbonaceous nanoparticle/carbon composite anode material using no binder; a lithium-polymer battery having high capacity and high rapid charge/discharge characteristics using the same; and a preparation method thereof. According to the present invention, the lithium-polymer secondary battery comprises an anode active material prepared by carbonizing a composite in which polymer particles comprising non-carbonaceous nanoparticles are dispersed in a polymer resin. According to the present invention, the anode active material allows non-carbonaceous nanoparticles to be dispersed in and fixed to a carbonized body even without a binder.

Abstract: Disclosed herein are cathode formulations comprising a lithium ion-based electroactive material having a D50 ranging from 1 ?m to 6 ?m; and carbon black having BET surface area ranging from 130 to 700 m2/g and an OAN ranging from 150 mL/100 g to 300 mL/100 g. Also disclosed are cathode formulations comprising a first lithium ion-based electroactive material having a particle size distribution of 1 ?m?D50?5 ?m, and a second lithium ion-based electroactive material having a particle size distribution of 5 ?m<D50?15 ?m. Cathodes comprising these active materials can exhibit a maximum pulse power in W/kg and W/L of the mixture higher than maximum pulse power of the first or second electroactive material individually, or an energy density in Wh/kg and Wh/L of the mixture higher than energy density of the first or second electroactive material individually. The cathode formulations can further comprise carbon black having BET surface area ranging from 130 to 700 m2/g.

Abstract: The present disclosure provides a sheet-form electrode for a secondary battery, comprising a current collector; an electrode active material layer formed on one surface of the current collector; and a first porous supporting layer formed on the electrode active material layer. The sheet-form electrode for a secondary battery according to the present disclosure has supporting layers on at least one surface thereof to exhibit surprisingly improved flexibility and prevent the release of the electrode active material layer from a current collector even if intense external forces are applied to the electrode, thereby preventing the decrease of battery capacity and improving the cycle life characteristic of the battery.

Abstract: The present invention relates to a conductive material for a secondary battery, including a pitch coated graphene sheet, an anode for a secondary battery including the same, and a lithium secondary battery including the electrode.

Abstract: A method includes combining a coating material and an uncoated particulate core material in a solution having a selected ionic strength. The selected ionic strength promotes coating of the uncoated particulate core material with the coating material to form coated particles; and the coated particles can be collected after formation. The coating material has a higher electrical conductivity than the core material.

Abstract: Provided is a negative electrode for a non-aqueous electrolyte secondary battery, capable of improving the energy density and the cycle characteristics of the battery without lowering the initial charge/discharge efficiency of the battery. This negative electrode includes a negative electrode active material including a silicon oxide represented by SiOx and carbon material. A proportion of a mass of the silicon oxide relative to a total mass of the silicon oxide and the carbon material: y satisfies 0.03?y?0.3. A difference between a theoretical capacity density of the negative electrode active material and a charge capacity density of the negative electrode active material when a cutoff voltage is 5 mV relative to lithium metal: ?C (mAhg?1) satisfies L=?C/100 and 6y?L?12y+0.2.

Abstract: A non-aqueous electrolyte secondary battery comprising a positive electrode plate, a negative electrode being provided with a negative electrode plate mixture layer containing a negative electrode active material, a separator; and a non-aqueous electrolyte. The negative electrode active material is a mixture of at least one of metal silicon and silicon oxide expressed by SiOx (0.5?x<1.6) , and graphite material. And the graphite material includes coated graphite material coated with amorphous carbon in the ratio of equal to or more than 20% by mass, and equal to or less than 90% by mass to all the graphite material, and the ratio of the metal silicon and the silicon oxide to all the negative electrode active material is equal to or more than 1% by mass and equal to or more than 20% by mass.