A power storage system includes a power storage element; and a voltage detecting unit configured to detect an output voltage of the power storage element. The power storage element and the voltage detecting unit are formed by integrally forming structural materials of the power storage element and the voltage detecting unit on the same base material, without any point bonding portions formed by solder mounting.

Systems and methods for electrode lamination using overlapped irregular shaped active material may include a battery having a cathode, an electrolyte, and an anode, with the anode including an active material on a metal current collector. The active material may include a plurality of irregularly shaped pieces bonded to the metal current collector, and may include silicon, carbon, and a pyrolyzed polymer. The active material may include more than 50% silicon by weight. The plurality of irregularly shaped pieces may be roll press laminated to the metal current collector. Gaps may remain between some of the irregularly shaped pieces of active material. The gaps may absorb strain in the active material during lithiation of the anode. The metal current collector may include a copper or nickel foil. Portions of the metal current collector not covered by active material may be protected by an adhesive or inorganic layer.

A lithium ion battery includes a cathode having a composite cathode active material and an anode having an anode active material. The composite cathode active material includes at least one first and one second cathode active material, wherein the second cathode active material is a compound having a spinel structure and wherein at least a lithiation degree of the first cathode active material differs from a lithiation degree of the second cathode active material. A degree of lithiation a of the first cathode active material is higher than a degree of lithiation b of the second cathode active material before electrolyte filling and before the first discharging and/or charging process of the lithium ion battery. The anode active material is pre-lithiated before the electrolyte filling and the first discharging and/or charging process of the lithium ion battery. A method for producing such a lithium ion battery is also described.

The alkaline battery of the present invention includes, as power generation components, a positive electrode containing silver oxide as a positive electrode active material, a negative electrode, a separator, and an alkaline electrolyte solution. At least one of the power generation components contains tellurium or a compound of tellurium. The total content of tellurium element contained in components housed in the battery is 0.4 parts by mass or more with respect to 100 parts by mass of the total amount of silver element in the positive electrode active material. The positive electrode is substantially free of cadmium.

This electrode plate for a non-aqueous electrolyte secondary battery comprises: an electrode core with an undercoat layer formed on the surface thereof; and an electrode composite layer formed on the undercoat layer of the electrode core. The undercoat layer can be obtained by applying an undercoat dispersion liquid on the surface of the electrode core and drying the dispersion liquid. The average diameter of an electroconductive auxiliary agent used for the undercoat layer is no greater than 12 nm. The molecular weight of a binder used for the undercoat layer is no less than 900,000. The thickness of the undercoat layer is no greater than 20 μm. The molecular weight of a binder used for the electrode composite layer is no less than 900,000.

This electrode plate for a non-aqueous electrolyte secondary battery has: an electrode core having an undercoat layer formed on the surface thereof; an electrode mixture layer formed on the undercoat layer of the electrode core. The undercoat layer is obtained by applying an undercoat dispersion on the surface of the electrode core and drying the same. A conductive auxiliary agent used for the undercoat layer is formed of carbon nanotubes. The average diameter of the conductive auxiliary agent is 12 nm or less. The aspect ratio (average length/average diameter) of the conductive auxiliary agent is 4000 or greater. The thickness of the undercoat layer is 0.10 μm or less.

A positive electrode active material includes a lithium transition metal oxide, which is in the form of a secondary particle formed by aggregation of primary particles and is represented by Formula 1, wherein the lithium transition metal oxide has a crystalline size of 160 nm or less and an average particle diameter of the primary particle of 0.6 μm or more. A preparation method thereof is also provided.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes a positive electrode active material, a positive electrode binder, and a positive electrode conductor. The negative electrode includes a negative electrode active material. The positive electrode active material includes a lithium-cobalt composite oxide. The positive electrode binder includes a vinylidene fluoride polymer having a melting point of higher than or equal to 160° C. and lower than or equal to 170° C. The positive electrode conductor includes carbon black having a hollow structure. The negative electrode active material includes a carbon material.

An electrode material of the present disclosure includes an active material and a solid electrolyte. The length of an interface between the active material and the solid electrolyte per unit area of the cross section of the electrode material is 0.29 μm/μm.sup.2 or more, and the filling rate of the electrode material is 80% or more. A battery of the present disclosure includes a first electrode, a second electrode, and an electrolyte layer positioned between the first electrode and the second electrode. At least one selected from the group consisting of the first electrode and the second electrode includes the electrode material of the present disclosure.

A lithium secondary battery according to an embodiment of the present invention comprises a cathode and an anode. The cathode comprises lithium metal oxide particles that contains lithium and metal elements. The lithium metal oxide particles have a concentration gradient region formed in at least one region between a center and a surface. A concentration of at least one of the metal elements is changed in the concentration gradient region. The anode comprises an anode active material that contains a silicon-based active material and a carbon-based active material. A content of the carbon-based active material in the anode active material is greater than a content of the silicon-based active material.