Abstract: The present invention provides a lithium secondary battery that has high energy density and excellent cycle characteristics, and a method for using this battery. The present invention relates to a lithium secondary battery comprising: a positive electrode current collector; a positive electrode formed on at least one surface of the positive electrode current collector and having a positive electrode active material; a negative electrode free of a negative electrode active material; and a separator or solid electrolyte disposed between the positive electrode and the negative electrode, wherein the positive electrode contains a Li(Ni, Co, Mn)O2 crystal and/or a Li(Ni, Co, Al)O2 crystal whose full width at half maximum for the diffraction peak of the (003) plane as measured by X-ray diffraction that is greater than 0.00° and 0.10° or less in an amount of 20% by mass or more and 100% by mass or less relative to the total mass of the positive electrode active material.

Abstract: A battery system, control device, and control method are provided that can improve the cycle service life.

Abstract: The present invention provides a secondary battery that has high energy density, high capacity, excellent cycle characteristics, and high productivity. The present invention relates to a secondary battery including: a laminate formed by alternately folding a sheet at an acute angle a plurality of times, the sheet having a negative electrode that is free of a negative electrode active material, and separators or solid electrolytes disposed on both surfaces of the negative electrode; and a plurality of positive electrodes each disposed in a space between separators or solid electrolytes facing each other formed by folding the sheet.

Abstract: The present invention provides a battery that has excellent energy density and cycle characteristics early in the cycle. The battery in one aspect of the present invention comprises a positive electrode, a negative electrode that is free of a negative electrode active material, a separator that is disposed between the positive electrode and the negative electrode, and a conductive thin film that is disposed between the separator and the negative electrode. The thickness of the conductive thin film is 1 ?m or less.

Abstract: A lithium secondary battery is provided that has high energy density and excellent cycle characteristics. This lithium secondary battery includes: a positive electrode; a separator or a solid electrolyte; a negative electrode that is free of a negative electrode active material; and optionally, an electrolytic solution, wherein charging and discharging are performed by depositing lithium metal on the surface of the negative electrode and electrolytically dissolving the deposited lithium, and the lithium secondary battery includes an additive that inhibits anisotropic crystal growth of the lithium metal by being codeposited with the lithium metal during charging.

Abstract: A secondary battery with excellent cycle characteristics is provided. An aspect of the present invention is a secondary battery comprising: a battery element that performs charging and discharging between a positive electrode and a negative electrode that is free of a negative electrode active material; a pair of elastic members disposed so as to interpose the battery element on both sides; a pair of supports that are disposed so as to interpose the pair of elastic members on both sides; and a pressure-applying member that applies pressure from both sides of the pair of supports, wherein the surface area of the surface of the elastic members facing the battery element is 1.2 to 2.0 times that of the surface area of the surface of the positive electrode that faces an elastic member, and the average pressure applied to this surface of the positive electrode is 1.0 to 3.0 MPa.

Abstract: A battery is provided that has excellent energy density and excellent cycle characteristics early in the cycle. The battery in one aspect of the present invention comprises: a positive electrode; a negative electrode free of a negative electrode active material; a separator that is disposed between the positive electrode and the negative electrode; and a carbon layer that is disposed between the separator and the negative electrode, wherein the capacity of the carbon layer is 22% or less of the capacity of the positive electrode.

Abstract: The present invention provides a solid-state battery with high energy density and excellent cycle property, and a production method therefor. The production method for this solid-state battery, which contains a positive electrode, a solid electrolyte, and a negative electrode, comprises the steps of: preparing a negative electrode that is free of a negative-electrode active material; and forming, on at least one surface of the negative electrode, a solid electrolyte interface layer including a lithium-containing organic compound and a lithium-containing inorganic compound by immersing the negative electrode in a layer forming solution containing a lithium salt and a precursor and thereafter causing a reduction reaction on the surface of the negative electrode.

Abstract: It is an object of the present invention to provide a solid-state battery having high energy density and excellent cycle property. The solid-state battery comprises a positive electrode, a solid electrolyte, and a negative electrode that is free of a negative-electrode active material. The solid electrolyte has a solid polymer electrolyte layer, and a functional layer that has a surface facing at least the negative electrode and that suppresses the formation of dendrites on the surface of the negative electrode.