Protection assembly, cover and housing

1. A battery module, comprising a case, a plurality of secondary batteries that comprise pressure relief elements and are disposed in the case, and a cover configured to connect to the case, wherein the pressure relief element is structured to deform in response to an increasing internal pressure in the secondary battery until the pressure relief element bursts, and the secondary battery can expel high temperature particles through the burst pressure relief element, wherein

the cover comprises a cover body and a protection assembly, wherein the protection assembly and the cover body are stacked; and

the protection assembly comprises:

a particle-blocking layer comprising a receiving side for receiving the high temperature particles and a connecting side opposite to the receiving side, wherein the particle-blocking layer comprises a plurality of particle-blocking units in a concave-convex arrangement, and the particle-blocking unit can block the high temperature particles; and

a separate protective layer disposed at the connecting side of the particle-blocking layer and connected to the particle-blocking layer,

wherein the particle-blocking layer comprises a sheet body and a plurality of protrusions protruding from a surface of the body in its thickness direction and spaced apart from each other, each particle-blocking unit comprises two adjacent protrusions and a concave between the two adjacent protrusions, the separate protective layer is disposed on a surface of the body away from the protrusions, and the two adjacent protrusions in the particle-blocking layer satisfy a relation (1),

0.005≤ d /( D−d )≤5  (1)

wherein the two adjacent protrusions each has a projection on the surface of the body, and a straight connecting line between respective central points of the two adjacent protrusions in the projections is denoted as H, and wherein in the relation (1), d refers to a dimension from a central point of one of the two adjacent protrusions in the projection to its own edge in the projection along the straight connecting line, and D refers to a dimension from a central point of one of the two adjacent protrusions in the projection to an edge of the other protrusion in the projection along the straight connecting line.

2. The battery module according to claim 1 , wherein the particle-blocking layer is configured to have a structure in which the high temperature particles can be accumulated on the particle-blocking units by accumulation.

3. The battery module according to claim 1 , wherein the particle-blocking layer and the separate protective layer are stacked.

4. The battery module according to claim 1 , wherein the particle-blocking layer has a resistance to melting of 500° C. to 3000° C.

5. The battery module according to claim 2 , wherein the particle-blocking layer has a resistance to melting of 500° C. to 3000° C.

6. The battery module according to claim 3 , wherein the particle-blocking layer has a resistance to melting of 500° C. to 3000° C.

7. The battery module according to claim 1 , wherein a resistance to melting of the particle-blocking layer is inversely proportional to its tolerance time, the temperature tolerance of the particle-blocking layer is ranged from 500° C. to 2000° C., and accordingly the tolerance time for melting of the particle-blocking layer is from 2 s to 3600 s.

8. The battery module according to claim 2 , wherein a resistance to melting of the particle-blocking layer is inversely proportional to its tolerance time, the temperature tolerance of the particle-blocking layer is ranged from 500° C. to 2000° C., and accordingly the tolerance time for melting of the particle-blocking layer is from 2 s to 3600 s.

9. The battery module according to claim 3 , wherein a resistance to melting of the particle-blocking layer is inversely proportional to its tolerance time, the temperature tolerance of the particle-blocking layer is ranged from 500° C. to 2000° C., and accordingly the tolerance time for melting of the particle-blocking layer is from 2 s to 3600 s.

10. The battery module according to claim 1 , wherein the particle-blocking layer is made of iron and its alloys, copper and its alloys, nickel alloys, carbon fiber or aramid; and/or the separate protective layer is made of organic foam, aerogel composite material, fireproof fabrics or fireproof coatings.

11. The battery module according to claim 2 , wherein the particle-blocking layer is made of iron and its alloys, copper and its alloys, nickel alloys, carbon fiber or aramid; and/or the separate protective layer is made of organic foam, aerogel composite material, fireproof fabrics or fireproof coatings.

12. The battery module according to claim 3 , wherein the particle-blocking layer is made of iron and its alloys, copper and its alloys, nickel alloys, carbon fiber or aramid; and/or the separate protective layer is made of organic foam, aerogel composite material, fireproof fabrics or fireproof coatings.

13. The battery module according to claim 1 , wherein the separate protective layer has a thickness of 0.5 mm to 10 mm.

14. The battery module according to claim 2 , wherein the separate protective layer has a thickness of 0.5 mm to 10 mm.

15. The battery module according to claim 3 , wherein the separate protective layer has a thickness of 0.5 mm to 10 mm.

16. The battery module according to claim 1 , wherein the protection assembly further comprises an insulation layer connected to the particle-blocking layer, wherein the insulation layer and the separate protective layer are disposed at two respective sides of the particle-blocking layer, and the insulation layer covers the particle-blocking units.

17. The battery module according to claim 2 , wherein the protection assembly further comprises an insulation layer connected to the particle-blocking layer, wherein the insulation layer and the separate protective layer are disposed at two respective sides of the particle-blocking layer, and the insulation layer covers the particle-blocking units.

18. The battery module according to claim 3 , wherein the protection assembly further comprises an insulation layer connected to the particle-blocking layer, wherein the insulation layer and the separate protective layer are disposed at two respective sides of the particle-blocking layer, and the insulation layer covers the particle-blocking units.

19. A battery pack, wherein the battery pack comprises a plurality of battery modules according to claim 1 , wherein the battery pack is provided with a housing comprising:

a first housing member; and

a second housing member connected to the first housing member in a sealed manner, wherein the first housing member and the second housing member form an accommodation space for receiving the battery modules;

wherein the protection assembly is disposed on a surface of the first housing member and/or the second housing member facing the battery modules.

20. The battery pack according to claim 19 , wherein the particle-blocking layer is configured to have a structure in which the high temperature particles can be accumulated on the particle-blocking units by accumulation.