Housing Cover for a Battery Housing With Particle Protection and Heat Protection, Battery Housing, Traction Battery and Motor Vehicle

Abstract

A housing cover is provided for placement on a housing lower part of a battery housing of a traction battery of an electrically driveable motor vehicle. The housing cover includes a cover layer for closing off a housing interior of the battery housing accommodating at least one battery cell, and a protection layer overlapping at least in part with the cover layer to withstand a thermal load caused by a supply of heat to the housing cover in the event of an emergency gassing of the at least one battery cell. The protection layer is mechanically connected in connection regions to the cover layer and is arranged in protection regions at a distance from the cover layer, thus forming a gap intended to increase a thermal transfer resistance between the protection layer and the cover layer.

Claims

1.-9. (canceled)

10. A housing cover for placement on a housing lower part of a battery housing of a traction battery of an electrically drivable motor vehicle, comprising: a cover layer of the battery housing, the cover layer being configured to close off a housing interior that receives at least one battery cell; a protective layer overlapping with the cover layer at least in certain regions to withstand a thermal load caused by heat applied to the housing cover in an event of emergency degassing of the at least one battery cell, wherein the protective layer is mechanically connected to the cover layer in connection regions and, in protective regions, is arranged at a distance from the cover layer so as to form a gap intended to increase a thermal transfer resistance between the protective layer and the cover layer.

11. The housing cover according to claim 10, wherein the cover layer has a lower melting point than the protective layer.

12. The housing cover according to claim 10, wherein the cover layer is made of aluminum.

13. The housing cover according to claim 10, wherein the protective layer is made of steel.

14. The housing cover according to claim 10, wherein the protective layer is connected to the cover layer in the connection regions without use of an additional material.

15. The housing cover according to claim 10, wherein a clinched connection connects the protective layer to the cover layer in the connection regions.

16. A battery housing for a traction battery of an electrically drivable motor vehicle, comprising: a housing lower part; and a housing cover comprising: a cover layer of the battery housing, the cover layer being configured to close off a housing interior that receives at least one battery cell; a protective layer overlapping with the cover layer at least in certain regions to withstand a thermal load caused by heat applied to the housing cover in an event of emergency degassing of the at least one battery cell, wherein the protective layer is mechanically connected to the cover layer in connection regions and, in protective regions, is arranged at a distance from the cover layer so as to form a gap intended to increase a thermal transfer resistance between the protective layer and the cover layer, wherein the cover layer has an upper side facing surroundings of the battery housing and an underside facing the housing interior, and wherein the protective layer is arranged on the underside of the cover layer.

17. A traction battery for an electrically drivable motor vehicle, comprising: a plurality of battery cells; and a battery housing, comprising: a housing lower part; and a housing cover comprising: a cover layer of the battery housing, the cover layer being configured to close off a housing interior that receives the plurality of battery cells; a protective layer overlapping with the cover layer at least in certain regions to withstand a thermal load caused by heat applied to the housing cover in an event of emergency degassing of at least one battery cell, wherein the protective layer is mechanically connected to the cover layer in connection regions and, in protective regions, is arranged at a distance from the cover layer so as to form a gap intended to increase a thermal transfer resistance between the protective layer and the cover layer, wherein the cover layer has an upper side facing surroundings of the battery housing and an underside facing the housing interior, and wherein the protective layer is arranged on the underside of the cover layer.

18. An electrically drivable motor vehicle comprising a traction battery according to claim 17.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0018] FIG. 1 is a schematic illustration of a detail of a traction battery according to an embodiment of the invention for an electrically drivable motor vehicle.

DETAILED DESCRIPTION OF THE DRAWING

[0019] Referring to FIG. 1, the traction battery 1 has a battery housing 2 which comprises a housing lower part 3 and a housing cover 4. The housing lower part 3 and the housing cover 4 enclose a housing interior 5 in which a plurality of battery cells 6 can be arranged. The battery cells 6 can be designed, for example, as prismatic cells. The battery cells 6 each have, for example, a cell housing 7 with a degassing element 8. The degassing element 8 can be, for example, a rupture membrane. In the event of degassing of a cell or emergency degassing of a battery cell 6, it is possible by way of the degassing element 8 for a hot gas which forms in the cell housing 7 to escape from the cell housing 7 into the housing interior 5. This hot gas transports heat to the housing cover 4, which is arranged above the battery cells 6 and thus overlapping with the degassing elements 8.

[0020] In order now to prevent the housing cover 4 being destroyed by the hot gas, the housing cover 4 is of multilayer design at least in certain regions. The housing cover 4 has a cover layer 9 which has an underside 10 facing the housing interior 5 and an upper side 12 facing the surroundings 11. The cover layer 9 is formed in particular as an aluminum sheet which seals the housing interior 5 and protects it from corrosion. On the underside 10 of the cover layer 9 there is arranged a protective layer 13. Here, the protective layer 13 is arranged on the cover layer 9 at least above the degassing element 8 of the battery cells 6, with the result that only the protective layer 13, but not the cover layer 9, is directly exposed to the outflowing hot gas. The protective layer 13 is more heat-resistant to the heat transported by the hot gas than the cover layer 9 and has for this purpose in particular a higher melting point than the cover layer 9. The protective layer 13 can be, for example, a steel sheet.

[0021] Here, the protective layer 13 is mechanically connected to the cover layer 9 in connection regions 14, which are here illustrated as being greatly enlarged. Away from the connection regions 14 there are formed protection regions 15 in which the protective layer 13 is arranged at a distance from the cover layer 9 with the formation of an, in particular air-filled, gap 16. The protective layer 13 is thus connected to the cover layer 9 in certain regions and is arranged at a distance from the cover layer 9 in certain regions. Here, the connection regions 14 can be produced by clinching. In the connection regions 14, the housing cover 4 thus has a layer stack which is formed in particular only by the protective layer 13 and the cover layer 9. In the protection regions 15, the housing cover has a layer stack which is formed by the protective layer 13, the gap 16 and the cover layer 9.

[0022] By virtue of the gap 16, the thermal transfer resistance between the protective layer 13 and the cover layer 9 is increased. In particular, the thermal transfer resistance is set over a height 17 of the gap 16 in such a way that a thermally poorly conducting heat transfer path between the protective layer 13 and the cover layer 9 is formed via the gap 16. The heat of the hot gas thus acts on the cover layer 9 only to such an extent that a temperature of the cover layer 9 always remains below its melting point and the housing cover 4 thus mechanically withstands the thermal loading.