# US 2020/0403201 A1 · Apparatus and method for thermal runaway propagation prevention > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0403201 A1 - Document ID: US20200403201A1 - Status: Published application - Kind: A1 - Application number: 16/902,788 - Filed: 2020-06-16 - Published: 2020-12-24 - Earliest claimed: 2019-06-21 - Assignees: All Cell Technologies, LLC - Applicants: All Cell Technologies, LLC - Inventors: Said AL-HALLAJ; Benjamin SCHWEITZER; Samuel T. PLUNKETT - Web page: https://patentgrep.com/patent/US20200403201A1 ## CPC - H01M 50/3425: {in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member} - H01M 50/392: with means for neutralising or absorbing electrolyte; with means for preventing leakage of electrolyte through vent holes - H01M 10/653: characterised by electrically insulating or thermally conductive materials - H01M 10/6569: Fluids undergoing a liquid-gas phase change or transition, e.g. evaporation or condensation (heat pipes H01M10/6552) - H01M 50/211: adapted for pouch cells - H01M 50/213: adapted for cells having curved cross-section, e.g. round or elliptic (H01M50/209, H01M50/216 take precedence) - H01M 50/242: adapted for protecting batteries against vibrations, collision impact or swelling - H01M 50/383: Flame arresting or ignition-preventing means - H01M 50/394: {Gas-pervious parts or elements} - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A thermal propagation prevention device and method for a battery pack including a plurality of battery cells. The device includes a liquid loaded material, such as a hydrogel or liquid loaded superabsorbent polymer, contained in a propagation arrestor configured to cover at Least one of the plurality of battery cells. The liquid loaded material is configured to phase change under heat from a rupture of the at least one of the plurality of battery cells and release a quenching vapor. The vapor further dilutes the electrolyte released from the at least one of the plurality of battery cells. ## Claims ### Claim 1 A thermal propagation prevention device for a battery pack including a plurality of battery cells, the device comprising a propagation arrestor configured to cover at least one of the plurality of battery cells, the propagation arrestor enclosing an electrolyte diluter material configured to release a vapor under heat from a rupture of the at least one of the plurality of battery cells. ### Claim 2 (depends on 1) The device of claim 1, wherein the vapor dilutes the electrolyte released from the at least one of the plurality of battery cells. ### Claim 3 (depends on 1) The device of claim 1, wherein the electrolyte diluter material comprises a hydrogel or superabsorbent polymer material. ### Claim 4 (depends on 1) The device of claim 1, wherein the propagation arrestor extends over a terminal end of each of the plurality of battery cells. ### Claim 5 (depends on 1) The device of claim 1, wherein the propagation arrestor comprises an opening facing the at least one of the plurality of battery cells. ### Claim 6 (depends on 5) The device of claim 5, wherein the opening comprises a mesh cover configured to retain the electrolyte diluter material and allow electrolyte to enter the propagation arrestor. ### Claim 7 (depends on 5) The device of claim 5, further comprising a release opening configured to release a diluted electrolyte to a surrounding environment of the battery pack. ### Claim 8 (depends on 5) The device of claim 5, further comprising an actuation mechanism configured to apply heating or electrical field to rupture the electrolyte diluter material. ### Claim 9 (depends on 1) The device of claim 1, further comprising a composite array disposed around and between the plurality of battery cells, wherein the propagation arrestor extends over the plurality of battery cells on a side of the composite array. ### Claim 10 A battery pack comprising: a plurality of battery cells, each including an electrolyte material; a propagation arrestor extending over the plurality of battery cells, the propagation arrestor enclosing an electrolyte diluter material configured to release an electrolyte dilution vapor under heat from a rupture of one or more of the plurality of battery cells. ### Claim 11 (depends on 10) The battery pack of claim 10, wherein the electrolyte diluter material comprises a hydrogel or superabsorbent polymer material. ### Claim 12 (depends on 11) The battery pack of claim 11, wherein the hydrogel or superabsorbent polymer comprises a liquid loaded super absorbent material. ### Claim 13 (depends on 11) The battery pack of claim 11, further comprising a rupturable container enclosing the hydrogel or superabsorbent polymer. ### Claim 14 (depends on 10) The battery pack of claim 10, wherein the propagation arrestor comprises an opening facing the plurality of battery cells. ### Claim 15 (depends on 14) The battery pack of claim 14, wherein the opening comprises a mesh cover configured to retain the electrolyte diluter material and allow electrolyte to enter the propagation arrestor. ### Claim 16 (depends on 14) The battery pack of claim 14, further comprising a release opening configured to release a diluted electrolyte to a surrounding environment of the battery pack. ### Claim 17 (depends on 11) The battery pack of claim 11, further comprising a composite array disposed around and between the plurality of battery cells, the composite array including a heat absorbing microencapsulated phase change material. ### Claim 18 A method of containment of rupturing battery cells, the method comprising: directing thermal energy and electrolyte from a rupturing battery cell toward a stored liquid; heating and evaporating the stored liquid with the thermal energy; and releasing vapor from the stored liquid to dilute the electrolyte. ### Claim 19 (depends on 19) The method of claim 19, further comprising releasing diluted electrolyte to a surrounding environment. ### Claim 20 (depends on 19) The method of claim 19, wherein the stored liquid is contained in a hydrogel or superabsorbent polymer.