Provided is a positive electrode for a secondary battery in which carbon nanotubes are used, of which an initial resistance is small, and that suppresses an increase in resistance when charging and discharging are repeated. The positive electrode for a secondary battery disclosed herein includes a positive-electrode current collector and a positive-electrode active material layer provided on the positive-electrode current collector. The positive-electrode active material layer contains a positive-electrode active material and carbon nanotubes, and substantially does not contain a resin binder. The positive-electrode active material layer includes a layer-like region that is in contact with the positive-electrode current collector, and a region other than the layer-like region. Both of the layer-like region and the region other than the layer-like region contain carbon nanotubes. A content of carbon nanotubes in the layer-like region is larger than a content of carbon nanotubes in the region other than the layer-like region.

A battery includes positive and negative external terminals having exposed portions exposed from a casing to the outside, positive and negative current collectors connected to the external terminals, and electrode assemblies having positive and negative electrodes and a separator. The positive and negative electrodes are wound with the separator being interposed so as to have positions shifted to opposite sides in a width direction to the separator. Formed in the casing is a narrowly elongated gap extending between the positive current collector side and the negative current collector side. The positive electrode side of the gap is closed by a closure member. A foreign material is prevented from moving without decreasing an electric capacity of the battery and deteriorating injection property of an electrolytic solution.

A battery includes positive and negative external terminals having exposed portions exposed from a casing to the outside, positive and negative current collectors connected to the external terminals, and electrode assemblies having positive and negative electrodes and a separator. The positive and negative electrodes are wound with the separator being interposed so as to have positions shifted to opposite sides in a width direction to the separator. Formed in the casing is a narrowly elongated gap extending between the positive current collector side and the negative current collector side. The positive electrode side of the gap is closed by a closure member. A foreign material is prevented from moving without decreasing an electric capacity of the battery and deteriorating injection property of an electrolytic solution.

An electrochemical battery can include electrodes (a cathode and an electrode) arranged on respective surfaces of an electrolyte. The electrodes and electrolyte can each be solid state films that can be layered on top of one another to create a stacked structure disposed on a substrate. A polymeric sealant material can be applied over and around the battery stack and a moisture barrier can be formed over the sealant material to thereby prevent moisture from reaching the battery. Conductive terminals electrically coupled to the cathode and anode, respectively, can be formed on a second side of the substrate. As such, the battery can be flip-chip mounted to corresponding mounting pads and thereby connected to other electronics that can receive power from the battery.

A fluorine-substituted propylene carbonate-based electrolytic solution and a lithium-ion battery, particularly to a fluorine-substituted propylene carbonate-based electrolytic solution having fluorine-substituted propylene carbonate as a primary solvent and a co-solvent is disclosed. The fluorine-substituted propylene carbonate has 50-80 vol. %, and the co-solvent has 20-50 vol. %, based on the volume of the electrolytic solution for a lithium-ion battery.

A fluorine-substituted propylene carbonate-based electrolytic solution and a lithium-ion battery, particularly to a fluorine-substituted propylene carbonate-based electrolytic solution having fluorine-substituted propylene carbonate as a primary solvent and a co-solvent is disclosed. The fluorine-substituted propylene carbonate has 50-80 vol. %, and the co-solvent has 20-50 vol. %, based on the volume of the electrolytic solution for a lithium-ion battery.

Batteries and battery packs are provided. In one embodiment, the battery includes a positive electrode, a negative electrode, and an electrolyte including a fluidic electrolyte and a non-fluidic electrolyte. The fluidic electrolyte is configured to be imaged as a void image in a secondary electron image and a reflection electron image obtained by energy dispersive X-ray spectroscopy, and the non-fluidic electrolyte is configured to be imaged in the secondary electron image and the reflection electron image with a non-fluidic electrolyte contrast different from a contrast associated with a member selected from the group consisting of a solid current collector, an active material, a conductive material, a binding material and a separator.

Batteries and battery packs are provided. In one embodiment, the battery includes a positive electrode, a negative electrode, and an electrolyte including a fluidic electrolyte and a non-fluidic electrolyte. The fluidic electrolyte is configured to be imaged as a void image in a secondary electron image and a reflection electron image obtained by energy dispersive X-ray spectroscopy, and the non-fluidic electrolyte is configured to be imaged in the secondary electron image and the reflection electron image with a non-fluidic electrolyte contrast different from a contrast associated with a member selected from the group consisting of a solid current collector, an active material, a conductive material, a binding material and a separator.

Provided is an adhesive composition for an electrochemical device capable of forming an adhesive layer that has excellent adhesiveness in electrolysis solution and can improve electrical characteristics of an electrochemical device. The adhesive composition can be used for adhering an electrode assembly and a casing to one another. The adhesive composition contains organic particles having a core-shell structure including a core portion and a shell portion that partially covers an outer surface of the core portion. A polymer of the core portion has a degree of swelling in electrolysis solution of at least a factor of 5 and no greater than a factor of 30, whereas a polymer of the shell portion has a degree of swelling in electrolysis solution of greater than a factor of 1 and no greater than a factor of 4.

A secondary battery includes an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate, a case in which the electrode assembly and an electrolyte are received, and a finishing member attached to an outer surface of the electrode assembly. The finishing member includes a first layer, a second layer, and a third layer. The first layer has one surface attached to the electrode assembly. The second layer and the third layer are different from each other and are sequentially provided on another surface of the first layer. The second layer and the third layer react to the electrolyte.