APPARATUS AND METHOD FOR THERMAL RUNAWAY PROPAGATION PREVENTION

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.

2 . The device of claim 1 , wherein the vapor dilutes the electrolyte released from the at least one of the plurality of battery cells.

3 . The device of claim 1 , wherein the electrolyte diluter material comprises a hydrogel or superabsorbent polymer material.

4 . The device of claim 1 , wherein the propagation arrestor extends over a terminal end of each of the plurality of battery cells.

5 . The device of claim 1 , wherein the propagation arrestor comprises an opening facing the at least one of the plurality of battery cells.

6 . 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.

7 . The device of claim 5 , further comprising a release opening configured to release a diluted electrolyte to a surrounding environment of the battery pack.

8 . The device of claim 5 , further comprising an actuation mechanism configured to apply heating or electrical field to rupture the electrolyte diluter material.

9 . 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.

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.

11 . The battery pack of claim 10 , wherein the electrolyte diluter material comprises a hydrogel or superabsorbent polymer material.

12 . The battery pack of claim 11 , wherein the hydrogel or superabsorbent polymer comprises a liquid loaded super absorbent material.

13 . The battery pack of claim 11 , further comprising a rupturable container enclosing the hydrogel or superabsorbent polymer.

14 . The battery pack of claim 10 , wherein the propagation arrestor comprises an opening facing the plurality of battery cells.

15 . 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.

16 . 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.

17 . 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.

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.

19 . The method of claim 19 , further comprising releasing diluted electrolyte to a surrounding environment.

20 . The method of claim 19 , wherein the stored liquid is contained in a hydrogel or superabsorbent polymer.