Provided are a secondary battery, a battery module, and a battery pack, which have improved safety. Particularly, since a bulletproof material is disposed on the inside and/or the outside of an exterior part, even when a conductive needle-shaped member penetrates a secondary battery, heating, burning, discharge of evaporated electrolyte, and electrical contact between the needle-shaped member and an electrode can be prevented, thereby improving safety of the secondary battery, the battery module, and the battery pack.

A terminal covering resin film for secondary cell, which is attached so as to cover part of an outer surface of a terminal connected to a power generation element of a secondary cell, comprises an innermost layer contacting the terminal, and an outermost layer forming a surface opposite to the innermost layer wherein the innermost layer is a layer of not less than 20 μm in thickness containing an acid-modified polyolefin and a melt flow rate of the innermost layer is not less than 2.0 g/10 minutes.

Embodiments of the present invention provide a rechargeable battery including an electrode assembly including a first electrode and a second electrode. The electrode assembly is spirally-wound. The rechargeable battery also include a case has an opening into which the electrode assembly is inserted, a cover coupled to the case at the opening, and a terminal electrically connected to the second electrode. The terminal extends to the outside of the case. The electrode assembly includes two side surfaces facing opposite directions and two curved surfaces that connect the two side surfaces. A surface of the cover faces a first side surface of the two side surfaces.

A secondary battery includes an electrode assembly; a first pouch including an internal space accommodating the electrode assembly; and a second pouch coupled to at least one part of the first pouch and thermally bonded to at least one part of the first pouch, the first pouch and the second pouch sealing the electrode assembly. The first pouch and the second pouch each includes a body portion contacting the electrode assembly, the body portion comprising a back side, a front side opposite the back side, and two side surfaces between the back side and the front side; and a pair of wing portions respectively protruding from the two side surfaces of the body portion. A width of each of the pair of wing portions varies along the longitudinal direction of the electrode assembly such that the width of a central part of each of the pair of wing portions is greater than the width of either end part of each of the pair of wing portions.

The present invention relates to a battery module for storage of electrochemical cells, including a cover assembly including an inner frame that encloses an end of the cells and applies a compressive force thereto, an intermediate frame that is snap fit to an outer surface of the inner frame and supports ancillary structures of the battery system, and an outer cover that is snap fit to an outer surface of the intermediate frame.

A rechargeable battery having increased capacity while facilitating a manufacturing process is provided. A rechargeable battery includes: an electrode assembly including at least a unit body including a first region and a second region that are divided based on a folding center in which separators including at least two facing sheets are folded, and electrode plates of a first electrode and electrode plates of a second electrode, and the electrode plates of the first electrode and the electrode plates of the second electrode are alternately stacked with the separators therebetween in each of the first region and the second region: and a case receiving the electrode assembly and an electrolyte solution.

Battery pack includes: a plurality of chargeable/dischargeable cylindrical cells; battery holder in which the plurality of cylindrical cells are disposed; and thermally conductive resin that closely adheres to cylindrical cells, which are stored in battery holder, in a thermally coupled state above battery holder. Battery holder includes: bottom plate including a plurality of holding grooves in which cylindrical cells are disposed; and partition walls that are disposed between holding grooves and between adjacent cylindrical cells. Partition walls are lower than the diameter of cylindrical cells disposed in holding grooves, thermally conductive resin is disposed between adjacent cylindrical cells above partition walls, and thermally conductive resin interconnects adjacent cylindrical cells.

A heat insulating member includes a wall member. The wall member includes a high-density portion provided at one end edge in a direction orthogonal to a thickness direction of the wall member and having density of above 0.45 g/cm.sup.3 and a low-density portion provided midway in the direction orthogonal to the thickness direction, having heat-insulating properties, and having density of 0.45 g/cm.sup.3 or less. The high-density portion is provided over the entire one end edge and the thickness of the high-density portion is thinner than that of the low-density portion.

A packaging material for a power storage device, comprising: a coating layer disposed directly on a first surface of a metal foil or disposed via a first corrosion protection layer; and a second corrosion protection layer, a sealant adhesive layer, and a sealant layer disposed in this sequence on a second surface of the metal foil, wherein the coating layer is produced from an aromatic polyimide resin made of a tetracarboxylic dianhydride or derivatives thereof and a diamine or derivatives thereof, and wherein the coating layer has a tensile elongation in a tensile test (in compliance with JIS K7127, JIS K7127 specimen type 5, tensile rate 50 mm/min) is not less than 20% in an MD direction and a TD direction.

Approaches herein provide a device, such as a battery protection device, including a cathode current collector and an anode current collector provided atop a substrate, a cathode provided atop the cathode current collector, and an electrolyte layer provided over the cathode. An interlayer, such as one or more layers of silicon, antimony, magnesium, titanium, magnesium lithium, and/or silver lithium, is formed over the electrolyte layer. An anode contact layer, such as an anode or anode current collector, is then provided over the interlayer. By providing the interlayer atop the electrolyte layer prior to anode contact layer deposition, lithium from the cathode side alloys with the interlayer, thus providing a more isotropic or uniaxial detachment of the anode contact layer.