Battery pack with improved safety

Abstract

The object of the present invention is to provide a battery pack with improved safety by slowing the propagation of heat and / or flames between cells under conditions of overheating or thermal runaway. [Solution] The present invention relates to a battery pack, which, in the event of thermal runaway in any of the multiple cell stack assemblies housed inside, minimizes the propagation of heat and resulting flames to adjacent assemblies. This has the advantage of improving the safety of the battery pack against ignition and explosion.

Claims

1. A battery pack containing multiple cell stack assemblies, A pack case comprising a base plate including a cell stack region in which the cell stack assembly is located, and a side pack frame extending vertically along the edge of the base plate and joined thereto so as to surround the cell stack region, Includes a pack case cover located on the upper part of the cell stack assembly located in the cell stack region and coupled to the upper end of the pack case, The cell stack assembly includes an isolation member on the outside which a heat-resistant plastic matrix is ​​included. The isolation member is a battery pack that does not form droplets even when in contact with a flame of 800 to 1,000°C for more than 5 minutes.

2. The battery pack according to claim 1, wherein the heat-resistant plastic matrix includes one or more compounds selected from acrylonitrile resins, acrylic resins, benzimidazole resins, indoline resins, imide resins, amide resins, phenylene oxide resins, butylene terephthalate resins, and copolymer resins thereof.

3. The battery pack according to claim 1 or 2, wherein the isolation member includes a single-layer sheet in which a fibrous structure is dispersed in the heat-resistant plastic matrix.

4. The battery pack according to claim 3, wherein the fiber structure is one or more of glass fibers, carbon fibers, and aramid fibers.

5. The battery pack according to claim 3, wherein the fiber structure is contained in an amount of 5 to 40% by weight relative to the total weight of the isolation member.

6. The battery pack according to claim 1 or 2, wherein the isolation member provided on the upper surface of the cell stack assembly includes a plurality of exhaust ports.

7. The battery pack according to claim 1 or 2, wherein a flame propagation prevention sheet is provided between the pack case cover and the isolation member.

8. The battery pack according to claim 7, wherein the flame propagation prevention sheet is a silicate sheet composed of a silicate containing one or more elements from silicon (Si), aluminum (Al), iron (Fe), magnesium (Mg), manganese (Mn), titanium (Ti), sodium (Na), potassium (K), fluorine (F), and oxygen (O).

9. The battery pack according to claim 7, wherein the flame propagation prevention sheet includes one or more of the following: muscovite, phengite, celadonite, paragonite, margalite, phlogopite, biotite, annite, iron mica, siderophyllite, clintonite, lithium muscovite, trilithionite, polylithionite, tsinwaldite, and striped mica.

10. The isolation member includes a plurality of exhaust ports provided so as to be perpendicular to the cell stacking direction of the cell stack assembly housed inside the pack case, The battery pack according to claim 7, wherein the flame propagation prevention sheet has an exhaust region that is partially cut along the exhaust port of the isolation member.

11. The battery pack according to claim 7, wherein the flame propagation prevention sheet has an average thickness of 0.5 to 5.0 mm.

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