Liquid-cooled battery device and method for manufacturing a liquid-cooled battery device

Abstract

The present invention relates to a liquid-cooled battery device (100-1; 100-2) with a housing (1) configured to be filled with a coolant (K) and with at least one battery cell (2) arranged in the housing (1), wherein the at least one battery cell (2) is fixed in the housing (1) by means of a cell fixing arrangement (3) comprising at least one cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2) arranged between the housing (1) and a battery cell (2) and consisting of a material that swells under the influence of the coolant (K). The present invention further relates to a method for manufacturing a liquid-cooled battery device (100-1; 100-2), wherein: at least one cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2) is arranged between the housing (1) and a battery cell (2) and consists of a material that swells under the influence of the coolant (K).2-2), which consists of a material that swells under the influence of a coolant (K), and at least one battery cell (2) is arranged in a housing (1) such that each cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2) is arranged between the housing (1) and a battery cell (2), and the coolant (K) is filled into the housing (1) to cause the at least one cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2) to swell and thereby fix the at least one battery cell (2) in the housing (1).

Description

[0001] The present invention relates to a liquid-cooled battery device comprising a housing configured to be filled with a cooling liquid and comprising a plurality of battery cells arranged in the housing. The present invention further relates to a method for producing a liquid-cooled battery device.

[0002] Battery devices of the type mentioned above are well known in the prior art and are used in particular as traction batteries in electrically or partially electrically powered vehicles.

[0003] From US 2019 / 0 097 281 A1 a battery device is known which has a housing and a plurality of battery cells arranged in the housing, wherein the battery cells each have a shell which is designed to be filled with a cooling liquid, and wherein the shell and / or a filling material arranged therein consist of a material which swells under the action of the cooling liquid.

[0004] From the subsequently published DE 10 2023 103 119 A1, a battery device of the type mentioned at the outset is known, wherein the battery cells are fixed in the housing via a cell fixing arrangement which comprises at least two expansion mats which are arranged on opposite sides of the battery cells, each between the housing and a plurality of battery cells, and which consist of a material which swells under the action of the cooling liquid.

[0005] From the subsequently published DE 10 2023 102 385 A1, a battery device is known which has a housing and a plurality of battery cells arranged in the housing, wherein at least one sealing mat is arranged in the housing, which consists of a material which swells under the action of the cooling liquid and has a number of receiving openings corresponding to the number of battery cells, in each of which a battery cell is arranged, and wherein the at least one sealing mat, in an expanded state, is pressed against all battery cells and the housing and delimits a liquid-tight housing interior within the housing, which is designed to be filled with the cooling liquid.

[0006] The present invention is based on the object of enabling a relatively simple production of a liquid-cooled battery device of the type mentioned above.

[0007] This object is achieved according to the invention by a liquid-cooled battery device having the features of claim 1 and by a method for producing a liquid-cooled battery device having the features of claim 6.

[0008] The battery device according to the invention comprises a liquid-tight housing configured to be filled with a preferably dielectric cooling liquid. The housing preferably comprises a cooling liquid inlet and a cooling liquid outlet to allow the cooling liquid to flow continuously through the housing during operation of the battery device. The housing preferably comprises a housing part configured as an extruded profile and is made at least partially of a metal.

[0009] The battery device according to the invention further comprises a plurality of battery cells arranged in the housing and surrounded by the cooling liquid for cooling during operation of the battery device. The battery cells generally comprise a gas-tight cell housing in which the active materials of the battery cell are arranged. The battery cells are preferably substantially plate-shaped and arranged parallel to one another. The battery device is preferably designed such that the cooling liquid flows around the battery cells during operation in order to achieve particularly effective cooling of the battery cells.

[0010] According to the invention, the battery cells are fixed in the housing via a cell fixing arrangement comprising at least one cell fixing element corresponding to the number of battery cells, each cell fixing element being arranged between the housing and a battery cell and made of a material that swells under the influence of the cooling liquid. The cell fixing elements can be made, for example, of an ethylene propylene diene rubber (EPDM) or a silicone, in which case the cell fixing elements absorb hydrocarbon chains from the cooling liquid and swell as a result. In any case, the cell fixing elements are made of a material that swells under the influence of the cooling liquid, i.e., that increases its volume upon direct physical contact with the cooling liquid by absorbing one or more chemical substances from the cooling liquid.

[0011] The cell fixing elements can be easily arranged in the housing with the battery cells in their non-swollen state. When the housing is subsequently filled with the cooling liquid, the cell fixing elements swell under the influence of the cooling liquid and clamp the battery cells in the housing, thereby reliably securing the battery cells in the housing. This enables relatively simple assembly of the battery cells in the housing and thus relatively simple production of the liquid-cooled battery device.

[0012] In a preferred embodiment, the cell fixation arrangement comprises at least one mat-shaped cell fixation element that essentially covers one side of a battery cell over its entire surface and thereby creates a full-surface tension of the battery cell when swollen. This enables particularly reliable fixation of the battery cells in the housing.

[0013] Additionally or alternatively, in a preferred embodiment, the battery device according to the invention comprises a plurality of relatively compact cell fixing elements, wherein a plurality of these relatively compact cell fixing elements are arranged on one side of a battery cell. The cell fixing elements are preferably arranged in an edge region of the respective side of the battery cell. In the case of prismatic battery cells, at least four of the relatively compact cell fixing elements are preferably arranged on a rectangular side of the battery cell, wherein the four cell fixing elements are advantageously arranged either at the edge centers or at the corners of the rectangular side.

[0014] This enables the realization of a cell fixation arrangement that enables reliable fixation of the battery cells with relatively low material expenditure.

[0015] Preferably, each battery cell of the battery device is assigned at least one cell fixing element, which is arranged between the respective battery cell and the housing and fixes the respective battery cell in one spatial direction in the swollen state, so that each battery cell is clamped directly against the housing and not against another battery cell in at least one spatial direction. This enables reliable fixation of the battery cells in the housing.

[0016] Particularly preferably, each battery cell is assigned at least two cell fixing elements, which are arranged on adjacent sides of the respective battery cell and fix the respective battery cell in the swollen state in two spatial directions perpendicular to each other, so that each battery cell is clamped directly against the housing in at least two spatial directions and not against another battery cell. This enables particularly reliable fixation of the battery cells in the housing.

[0017] Preferably, the cell fixing elements are each attached to a battery cell, so that the cell fixing elements can be arranged together with the battery cells in the housing, thus eliminating the need for a separate assembly step for arranging the cell fixing elements in the housing. This enables particularly simple production of the liquid-cooled battery device.

[0018] In the method according to the invention for producing a liquid-cooled battery device, a plurality of battery cells and at least one cell fixing element corresponding to the number of battery cells, each of which consists of a material that swells under the action of a cooling liquid, are arranged in a housing such that each cell fixing element is arranged between the housing and a battery cell. The cooling liquid is then poured into the housing to cause the cell fixing elements to swell and thereby fix the battery cells in the housing. This enables—as described above—a relatively simple assembly of the battery cells in the housing and thus a relatively simple production of the liquid-cooled battery device.

[0019] Preferably, the cell fixing elements are each attached to a battery cell and then arranged together with the battery cells in the housing, so that no separate assembly step is required for arranging the cell fixing elements in the housing. This enables particularly simple production of the liquid-cooled battery device.

[0020] Preferably, the housing is sealed before filling with the coolant, so that the battery cells can be clamped against the housing in all spatial directions by the expansion of the cell fixing elements. This enables particularly reliable fixation of the battery cells in the housing.

[0021] Preferably, the housing is initially filled with the coolant during assembly of the battery device to swell the cell fixing elements. The coolant is then drained again after the cell fixing elements have swollen. This ensures that the battery cells are already reliably secured in the housing during transport following assembly, significantly reducing the risk of damage to the battery cells during transport.

[0022] Embodiments of the present invention are described below with reference to the accompanying figures. Herein: Fig. 1 a schematic diagram of a battery device according to the invention, and Fig. 2 a schematic diagram of an alternative battery device according to the invention.

[0023] Fig. 1 shows a liquid-cooled battery device 100-1 according to the invention with a housing 1 which comprises a main housing part 1.1 designed as an extruded profile and two cover parts 1.2 fastened to the main housing part 1.1, wherein the housing 1 is filled with a dielectric cooling liquid K.

[0024] In the housing 1, several prismatic battery cells 2 are arranged, which are fixed in the housing 1 via a cell fixing arrangement 3.

[0025] The cell fixing arrangement 3 comprises a number of mat-shaped first cell fixing elements 3.1-1 corresponding to the number of battery cells 2 and a number of mat-shaped second cell fixing elements 3.2-1 corresponding to the number of battery cells 2, each of which consists of a material that swells under the action of the cooling liquid K, for example of EPDM or silicone.

[0026] Each battery cell 2 is assigned both a first cell fixing element 3.1-1 and a second cell fixing element 3.2-1, wherein the first cell fixing element 3.1-1 is attached to an end face 2.1 of the respective battery cell 2 and covers said cell substantially over its entire surface, and wherein the second cell fixing element 3.2-1 is attached to a longitudinal side 2.2 of the respective battery cell 2 and covers said cell substantially over its entire surface.

[0027] The first cell fixing element 3.1-1 is arranged between the end face 2.1 of the respective battery cell 2 and the housing 1 and fixes the respective battery cell 2 in Fig. 1 shown swollen state in a first spatial direction Y.

[0028] The second cell fixing element 3.2-1 is arranged between the long side 2.2 of the respective battery cell 2 and the housing 1 and fixes the respective battery cell 2 in Fig. 1 shown swollen state in a second spatial direction Z.

[0029] During the manufacture of the battery device 100-1, a non-swollen first cell fixing element 3.1-1 and a non-swollen second cell fixing element 3.2-1 are attached to each battery cell 2, and then the battery cell 2 is arranged in the housing 1 together with the non-swollen cell fixing elements 3.1-1, 3.2-1 arranged thereon.

[0030] After all battery cells 2 have been arranged in the housing 1, the housing 1 is closed by attaching the cover parts 1.2 to the main housing part 1.1.

[0031] The cooling liquid K is then poured into the closed housing 1 in order to allow the cell fixing elements 3.1-1, 3.2-1 to swell and thereby fix the battery cells 2 in the housing 1.

[0032] After the cell fixation elements 3.1-1, 3.2-1 as in Fig. 1, the cooling liquid K is drained out of the housing 1 again.

[0033] Fig. 2 shows an alternative liquid-cooled battery device 100-2 according to the invention, wherein for the designation of features which are different from the liquid-cooled battery device 100-1 Fig. 1 are identical or similar, the reference numerals from Fig. 1 can be used.

[0034] The liquid-cooled battery device 100-2 differs from the liquid-cooled battery device 100-1 in that a plurality of relatively compact cell fixing elements 3.1-2, 3.2-2 are attached both to the end face 2.1 of the battery cell 2 and to the longitudinal face 2.2 of the battery cell 2, wherein the cell fixing elements 3.1-2, 3.2-2 of the liquid-cooled battery device 100-2 differ from the cell fixing elements 3.1-1, 3.2-1 of the liquid-cooled battery device 100-1 only in their shape but not in their functioning.

[0035] The production of the liquid-cooled battery device 100-2 differs from the production of the liquid-cooled battery device 100-1 only in that a plurality of first cell fixing elements 3.1-2 are attached to the end face 2.1 of each battery cell 2 and a plurality of second cell fixing elements 3.2-2 are attached to the long side 2.2 of each battery cell 2. List of reference symbols 100-1; 100-2 liquid-cooled battery device 1 housing 1.1 Main housing part 1.2 Cover parts 2 battery cells 2.1 Front side 2.2 Long side 3 Cell fixation arrangement 3.1-1; 3.1-2 first cell fixation elements 3.2-1; 3.2-2 second cell fixation elements K Coolant Y first spatial direction Z second spatial direction

Claims

[1] Liquid-cooled battery device (100-1; 100-2) with a housing (1) which is designed to be filled with a cooling liquid (K), and with a plurality of battery cells (2) arranged in the housing (1), wherein the battery cells (2) are fixed in the housing (1) via a cell fixing arrangement (3) which comprises at least one number of cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) corresponding to the number of battery cells (2), which are each arranged between the housing (1) and a battery cell (2) and consist of a material which swells under the action of the cooling liquid (K), wherein each battery cell (2) is assigned at least one cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2), which is arranged between the respective battery cell (2) and the housing (1) and which fixes the respective battery cell (2) in the swollen state fixed in one spatial direction (Y, Z). [2] Battery device (100-1) according to claim 1, wherein the cell fixing arrangement (3) comprises at least one mat-shaped cell fixing element (3.1-1, 3.2-1) which covers one side (2.1, 2.2) of a battery cell (2) substantially over its entire surface. [3] Battery device (100-2) according to one of the preceding claims, wherein a plurality of cell fixing elements (3.1-2, 3.2-2) are arranged on one side (2.1, 2.2) of a battery cell (2). [4] Battery device (100-1; 100-2) according to one of the preceding claims, wherein each battery cell (2) is assigned at least two cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2), which are arranged on adjacent sides (2.1, 2.2) of the respective battery cell (2) and fix the respective battery cell (2) in the swollen state in two mutually perpendicular spatial directions (Y, Z). [5] Battery device (100-1; 100-2) according to one of the preceding claims, wherein the cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) are each attached to a battery cell (2). [6] A method for manufacturing a liquid-cooled battery device (100-1; 100-2), wherein: a plurality of battery cells (2) and at least one number of cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) corresponding to the number of battery cells (2), each consisting of a material that swells under the action of a cooling liquid (K), are arranged in a housing (1) in such a way that each cell fixing element (3.1-1, 3.2-1; 3.1-2, 3.2-2) is arranged between the housing (1) and a battery cell (2), and the cooling liquid (K) is filled into the housing (1) in order to swell the cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) and thereby fixing the battery cells (2) in the housing (1). [7] Method according to claim 6, wherein the cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) are each attached to a battery cell (2) and arranged together with the battery cells (2) in the housing (2). [8] Method according to claim 6 or 7, wherein the housing (1) is closed before filling the cooling liquid (K). [9] Method according to one of claims 6 to 8, wherein the cooling liquid (K) is drained off again after the cell fixing elements (3.1-1, 3.2-1; 3.1-2, 3.2-2) have swollen.

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