A battery cell includes a housing. A dimension of the housing along a length direction of the battery cell is greater than a dimension of the housing along a thickness direction of the battery cell and a dimension of the housing along a width direction of the battery cell. The housing includes a board extending along the length direction and an accommodation space opened from at least one end of the accommodation space. The battery cell further includes an electrode assembly disposed in the accommodation space and a cover configured to cover the opening. A pressure relief mechanism is disposed at the board and configured to be actuated, in response to an internal pressure or temperature of the housing reaching a threshold, to relieve the internal pressure. In the length direction, an extension dimension of the pressure relief mechanism is greater than or equal to ¼ of an extension dimension of the board.

Provided are a secondary battery and a battery pack including the secondary battery. A sealing plate has a positive electrode terminal attachment hole. A positive electrode terminal penetrates the positive electrode terminal attachment hole. An external conductive member is connected to a portion of the positive electrode terminal located on the battery outer side with respect to the sealing plate. The conduction path between a positive electrode plate and the positive electrode terminal is provided with a current interrupting mechanism. A first insulating member made of resin is disposed between the sealing plate and the positive electrode terminal. A second insulating member having higher thermal resistance than the first insulating member is disposed between the external conductive member and the sealing plate.

Disclosed are a protection device for a secondary battery in which two flux cores are embedded in a fusible element to be separated from each other and be disposed adjacent to fusible element electrodes on both sides of the fusible element so that it is not necessary to apply a flux onto the surface of the fusible element, a manufacturing process for uniformly applying the flux is eliminated to significantly reduce a manufacturing cost, a first flux core and a second flux core embedded in the fusible element attract fused matters of the fusible element toward the fusible element electrodes on both sides of the fusible element when the fusible element is fused, to improve the fusing performance of the fusible element, and a current path is reliably cut off after the fusible element is fused.

Disclosed are a protection device for a secondary battery in which two flux cores are embedded in a fusible element to be separated from each other and be disposed adjacent to fusible element electrodes on both sides of the fusible element so that it is not necessary to apply a flux onto the surface of the fusible element, a manufacturing process for uniformly applying the flux is eliminated to significantly reduce a manufacturing cost, a first flux core and a second flux core embedded in the fusible element attract fused matters of the fusible element toward the fusible element electrodes on both sides of the fusible element when the fusible element is fused, to improve the fusing performance of the fusible element, and a current path is reliably cut off after the fusible element is fused.

The present invention concerns a fire safety arrangement for a battery. More particularly, but not exclusively, this invention concerns a fire safety arrangement for a metal ion battery, for example a lithium ion battery. A metal ion battery cell comprises a plurality of electrodes and an electrolyte encased within a housing. The housing comprises a safety valve or vent configured to allow gas build up within the housing to vent outside the housing. A fabric band surrounds the housing, such that the fabric band covers the safety valve or vent. This may allow gas to pass through the fabric band, but contain sparks generated by the battery cell within the fabric band.

Disclosed is a battery module with reduced risk of fire propagation or explosion. To achieve the above-described object, the battery module according to the present disclosure includes a cell assembly including a plurality of secondary batteries, a module housing in which the cell assembly is received in an internal space, the module housing having an opening through which the internal space is in communication with an external space, and an adjustment cover configured to cover at least a part of the opening to fill a fire extinguishing agent supplied into the battery module to a predetermined height or above.

Disclosed is a battery module with reduced risk of fire propagation or explosion. To achieve the above-described object, the battery module according to the present disclosure includes a cell assembly including a plurality of secondary batteries, a module housing in which the cell assembly is received in an internal space, the module housing having an opening through which the internal space is in communication with an external space, and an adjustment cover configured to cover at least a part of the opening to fill a fire extinguishing agent supplied into the battery module to a predetermined height or above.

A pressure relief apparatus, a battery cell, a battery, and an electrical device are provided in embodiments of the present application. The pressure relief apparatus includes a pressure relief body and a score groove. The pressure relief body includes a pressure relief portion configured to be opened to relieve a pressure inside the battery cell when an internal pressure or temperature of the battery cell reaches a threshold. The score groove is arranged on the pressure relief body and includes a first arc-shaped groove and a second arc-shaped groove. The arc-shaped design of the first arc-shaped groove and the second arc-shaped groove makes it less likely that the pressure relief portion cannot be opened in a large area, thereby improving the safety of the battery cell.

A negative electrode with little degradation is provided. Alternatively, a novel negative electrode is provided. A secondary battery includes a positive electrode and a negative electrode, and the negative electrode includes a solvent containing fluorine, a current collector, a negative electrode active material, and graphene. The negative electrode further includes a solid electrolyte material and the solid electrolyte material is an oxide. The negative electrode active material may contain fluorine. The secondary battery may include a plurality of electrolytes different from each other. The negative electrode active material is, for example, a material containing one or more elements selected from silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium.

A case having elasticity corresponding to expansion and contraction of a stacked body housed therein and a method for manufacturing the same, a method for inserting the stacked body into the case, and a cell stack using the case are provided. A case configured to house a stacked body includes two opposed contact parts in contact with the stacked body, and two spring structures connecting the two contact parts with each other.