COOLING MODULE FOR A CELL STACK, AND A CELL STACK

Abstract

The present invention relates to the field of electrical energy storage devices and in particular enables simplified manufacture and/or optimised operation thereof in that a cooling module, a cell stack, the entire electrical energy storage device and/or a method for cooling cells are optimised.

Claims

1-60. (canceled)

61. A cooling module for a cell stack, wherein the cooling module includes a cooling element for receiving and passing on a coolant, wherein the cooling module includes a carrier element to which the cooling element is fixed, wherein the carrier element is or includes an injection moulded plastics element that is fixed to the cooling element by being moulded onto it.

62. A cooling module according to claim 61, wherein the carrier element includes one or more corner elements that are in particular moulded directly onto the cooling element.

63. A cooling module according to claim 61, wherein the carrier element includes one or more stacking regions by means of which a plurality of carrier elements of the same construction are stackable on top of one another in a stack direction.

64. A cooling module according to claim 61, wherein the one or more stacking regions each include at least one reinforcing region and/or at least one clamping portion for clamping a plurality of carrier elements together by means of a clamping device.

65. A cooling module according to claim 61, wherein the carrier element includes one or more side parts that each include one or more anchoring portions for anchoring the carrier element on the cooling element.

66. A cooling module according to claim 65, wherein the one or more anchoring portions each include the following: one or more moulded-on elements, which are moulded directly onto the cooling element; and one or more web elements for connecting the moulded-on elements to a wall portion of a side part of the carrier element.

67. A cooling module according to claim 61, wherein the carrier element includes one or more side parts that each include one or more compensation regions, which are constructed to yield resiliently in a peripheral direction of the carrier element in which the carrier element surrounds the cooling element.

68. A cooling module according to claim 61, wherein the carrier element includes one or more side parts that each include a plurality of anchoring portions and a plurality of compensation regions, wherein the anchoring portions and the compensation regions are arranged alternately in a peripheral direction of the carrier element in which the carrier element surrounds the cooling element.

69. A cooling module according to claim 61, wherein the carrier element includes four corner elements and four side parts, each connecting two corner elements to one another, wherein the corner elements and the side parts jointly form a frame element surrounding the cooling element.

70. A cooling module according to claim 61, wherein the carrier element forms a wall portion of a housing of a cell stack and/or an electrical energy storage device.

71. A cooling module according to claim 70, wherein the wall portion has at least in part an undulating structure, wherein as a result of the undulating structure a plurality of compensation regions are formed for the equalisation of thermal expansions which differ as a result of the materials.

72. A cell stack, in particular an accumulator cell stack, wherein the cell stack includes the following: a plurality of cells, in particular accumulator cells; a plurality if cooling modules according to claim 61, for cooling the cells.

73. A cell stack according to claim 72, wherein a stack height of the carrier element corresponds at least approximately to a total of a thickness of at least one cooling element in a heat transfer region on the one hand and a thickness of at least one cell on the other.

74. A cell stack according to claim 72, wherein, in the stacked condition, the carrier elements of the cooling modules form a side wall of a housing encasing the cells and the cooling elements, wherein the side wall is at least approximately uninterrupted in both a stack direction and a peripheral direction.

75. A cell stack according to claim 72, wherein the cell stack includes a stack of carrier elements that is provided at both ends with a respective end plate, wherein the two end plates form or include clamping plates between which the carrier elements are clamped together.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0191] FIG. 1 shows a schematic perspective illustration of a cell stack of an electrical energy storage device, wherein the cell stack includes a plurality of carrier elements stacked on top of one another, for receiving cooling elements of the cooling modules, and a plurality of cells arranged between the cooling elements;

[0192] FIG. 2 shows a schematic perspective illustration of a plurality of mutually separated carrier elements, together with the cooling elements arranged thereon;

[0193] FIG. 3 shows a schematic perspective illustration of a carrier element, a layer of a cooling element to be arranged on the carrier element, a cell, and a layer of a further cooling element;

[0194] FIG. 4 shows a schematic plan view of a cooling module of the cell stack, with the direction of view in a stack direction of the cell stack;

[0195] FIG. 5 shows a schematic section through the cell stack, along the line 5-5 in FIG. 4;

[0196] FIG. 6 shows a schematic section through the cell stack, along the line 6-6 in FIG. 4;

[0197] FIG. 7 shows an illustration on a larger scale, of the region VII in FIG. 6;

[0198] FIG. 8 shows a schematic section through the cell stack, along the line 8-8 in FIG. 4; and

[0199] FIG. 9 shows a schematic section through the cell stack, along the line 9-9 in FIG. 4.

[0200] Like or functionally equivalent elements are provided with the same reference numerals in all the Figures.

DETAILED DESCRIPTION OF THE DRAWINGS

[0201] An embodiment, illustrated in FIGS. 1 to 9, of an electrical energy storage device that is designated 100 as a whole serves in particular to store electrical energy, and is used for example as an energy storage unit in electric vehicles.

[0202] The electrical energy storage device 100 includes a cell stack 102, which includes a plurality of cells 106 stacked in a stack direction 104.

[0203] The cells 106 are in particular so-called pouch cells 108 and/or prismatic cells.

[0204] A respective cooling element 110 of a cooling module 112 of the cell stack 102 is arranged in each case between two cells 106.

[0205] In this way, in particular a plurality of cooling modules 112 with cooling elements 110 on the one hand and cells 106 on the other are stacked on top of one another such that they alternate in the stack direction 104.

[0206] Here, the cooling elements 110 and the cells 106 abut against one another preferably over a large surface, in order to enable optimised heat transfer.

[0207] In the context of this description and the accompanying claims, the term abut against one another over a large surface is understood in particular to mean that the cooling elements 110 and the cells 106 abut against one another over a continuous part of a surface of the cooling elements 110 and the cells 106 of at least approximately 2 cm by 2 cm, in particular at least approximately 2 cm by 3 cm, preferably at least approximately 2 cm by 4 cm. For example, the cooling elements 110 and the cells 106 abut against one another over a continuous part of a surface of the cooling elements 110 and the cells 106 of at least approximately 4 cm.sup.2, in particular at least approximately 6 cm.sup.2, preferably at least approximately 10 cm.sup.2.

[0208] As can be seen in particular from FIGS. 3 and 7, each cooling element 110 includes two layers 114, which together form an outer casing 116 of the cooling element 110.

[0209] The layers 114 are made in particular of a metal material, or include such a material. In particular, the layers 114 take the form of layers of sheet metal.

[0210] Here, the layers 114 are in particular given a shape resulting in a peripheral, preferably substantially rectangular, edge region 118 in which the two layers 114 abut against one another. Further, as a result of the selected shape of the layers 114 there is produced an internal space 120 of the cooling element 110 that is formed between the two layers 114 and surrounded by the edge region 118.

[0211] The layers 114 are preferably connected to one another in fluid-tight manner in the edge region 118, in particular being seal welded.

[0212] Further, preferably a plurality of spray-through openings 122 is arranged and/or made in the edge region 118, and by means of these the cooling element 110 is configured to be fixed to a carrier element, to be described in more detail below.

[0213] The layers 114 each have one or more, for example two, passage apertures 124 through which the internal space 120 of the cooling element 110 is accessible.

[0214] The passage apertures 124 are in particular surrounded by a collar 126 that is formed from the respective layer 114 and forms a spigot 128 for receiving a connecting element 130.

[0215] A connecting element 130 serves in particular to connect two cooling elements 110 that succeed one another in the stack direction 104.

[0216] For this purpose, the connecting element 130 includes in particular two joining portions 132, each of which is configured to be pushed into a respective spigot 128 of the respective cooling element 110.

[0217] The connecting element 130 is thus in particular a push-in element 134 for pushing into the spigots 128 of the cooling elements 110.

[0218] For example one or more radial positioning projections 136 of the connecting element 130 are made and/or arranged substantially centrally in relation to the stack direction 104.

[0219] The radial positioning projections 136 form in particular abutments for positioning the two cooling elements 110 in relation to one another in the stack direction 104.

[0220] Thus, the connecting element 130 is at the same time a positioning element 138 for positioning the cooling elements 110 relative to one another in relation to the stack direction 104 and/or relative to two directions extending perpendicular thereto.

[0221] As can be seen in particular from FIG. 7, the layers 114 of each cooling element 110 take a form that, in relation to a centre plane 140, is mirror-symmetrical at least in certain regions, preferably substantially completely.

[0222] The spigots 128 for arranging the connecting elements 130 are thus arranged linearly successively in the stack direction 104, the final result of which is that a fluid duct 142, for example a supply duct 144 and/or a discharge duct 145, is formed in combination with the connecting elements 130.

[0223] A coolant can be supplied to the internal spaces 120 of the cooling elements 110 or discharged therefrom by way of the fluid duct 142.

[0224] One or more sealing elements 146 preferably serve for sealing in the contact region between the connecting elements 130 and the spigots 128. In particular, sealing elements 146 taking the form of O rings are provided.

[0225] A base body 148 of each connecting element 130 preferably has annular grooves for receiving the sealing elements 146.

[0226] As can be seen in particular from FIGS. 2, 3, 7 and 9, the cell stack 102 includes a plurality of carrier elements 150 for receiving and fixing the cooling elements 110.

[0227] In particular, each cooling module 112 includes respectively a carrier element 150 and a cooling element 110 arranged thereon.

[0228] The carrier elements 150 form in particular frame elements 152 that surround the respective cooling element 110 in a peripheral direction 154 in the manner of a frame, and are fixed to the respective cooling element 110 by being moulded onto it by a plastics injection moulding method.

[0229] The carrier elements 150 are thus in particular injection moulded plastics components.

[0230] As can be seen in particular from FIG. 4, each carrier element 150 includes a plurality, for example four, corner elements 156, wherein in each case two corner elements 156 are connected to one another by means of a respective side part 158.

[0231] Mutually opposing side parts 158 are preferably arranged substantially parallel to one another.

[0232] Side parts 158 that are connected to one another by means of a corner element 156 are preferably arranged at an angle of approximately 90 to one another.

[0233] The corner elements 156 are moulded in particular directly onto the edge region 118 of the cooling element 110, and in so doing are secured thereto such that they are immovable in relation to the cooling element 110.

[0234] The side parts 158 preferably include wall portions 160 of a wall 162 of a housing 164 to be described below.

[0235] The wall portions 160 connect to one another the two corner elements 156 that delimit the respective side part 158 in the peripheral direction 154.

[0236] The wall portions 160 of each side part 158 preferably take an undulating form. As a result, in particular compensation regions 166 are formed for the equalisation of changes in expansion caused by temperature.

[0237] The compensation regions 166 thus in particular enable deformation of the wall portion 160 of each side part 158, as a result of which the spacings between the corner elements 156 can be varied. This preferably allows the different expansion coefficients of the carrier element 150 made of plastics material, on the one hand, and the cooling element 110, which is made for example from metal, on the other, to be compensated.

[0238] The side parts 158 preferably include anchoring portions 168 by means of which the side parts 158 are fixed to the edge region 118 of the respective cooling element 110.

[0239] The anchoring portions 168 here each include a moulded-on element 170, which is applied directly on the edge region 118 of the cooling element 110 and extends for example through a spray-through opening 122 in the edge region 118.

[0240] The moulded-on element 170 is thus in particular fixed to the cooling element 110 with positive engagement.

[0241] A respective web element 172 preferably connects a moulded-on element 170 to the wall 162, in particular the wall portion 160 of the respective side part 158.

[0242] The wall 162 is thus preferably arranged at a spacing from the edge region 118 of the cooling elements 110 in the region of the side parts 158.

[0243] The corner elements 156 preferably include a stacking region 174 on which a plurality of identically formed carrier elements 150 are stackable on top of one another and in particular abut directly against one another.

[0244] Each stacking region 174 includes for example a reinforcing region 176 by means of which the respective corner element 156 is stabilised in the stack direction 104.

[0245] Further, the corner elements 156 include a clamping portion 178 that is arranged in particular in the region of the stacking region 174.

[0246] In particular, the clamping portion 178 serves to guide a clamping element 180 through the respective corner element 156 in order ultimately to provide a clamping device 182 by means of which the carrier elements 150 can be clamped together in the stack direction 104.

[0247] Further, for this purpose the clamping device 182 preferably also includes one or more clamping plates 184, which are formed in particular by two end plates 186 at both ends of the cell stack 102, and enable force to be introduced into the carrier elements 150 evenly.

[0248] The clamping elements 180 of the clamping device 182 are for example clamping rods 188 or threaded rods 190 that are terminated in particular by one or more threaded nuts 192 and thus enable the carrier elements 150 to be clamped together in the stack direction 104.

[0249] As can be seen in particular from FIGS. 3, 5 and 8, the cells 106 are preferably merely inserted between two respective cooling elements 110, for example being held therein.

[0250] An additional lateral fixing for the cells 106, in one or more directions extending perpendicular to the stack direction 104, is preferably not provided.

[0251] The cooling elements 110 in particular include a central heat transfer region 194 that is surrounded by the edge region 118 and in which the cooling elements 110 abut against the cells 106.

[0252] In particular, the cells 106 are held between the heat transfer regions 194 of two cooling elements 110 and are thus positioned in the stack direction 104.

[0253] A thickness D.sub.Z of the cell 106 and a thickness D.sub.K of a cooling element 110 and a stack height H of the carrier element 150 are preferably selected such that the two thicknesses D.sub.Z and D.sub.K together substantially correspond to the stack height H.

[0254] As a result, the carrier elements 150 can be laid directly on top of one another and thus stacked, while at the same time the cells 106 are positioned, in particular being held, in a closely abutting manner between the cooling elements 110.

[0255] Cell terminals 196 of the cells 106 are guided out of the cell stack 102 to the outside in particular through recesses or passage apertures in the carrier elements 150, provided for this purpose.

[0256] As can further be seen for example from FIGS. 4 and 8, the cooling elements 110 include for example a distributor duct 198 for evenly distributing supplied coolant to the heat transfer region 194.

[0257] Optionally, a collecting duct 200, indicated in FIG. 4, can moreover be provided for the purpose of bringing together coolant to be discharged from the heat transfer region 194.

[0258] When the electrical energy storage device 100 is in operation, fluctuations in the expansion of the cells 106 may occur, which depend in particular on the respective operating state, charging state and/or ageing state of the cells 106.

[0259] The fluctuations in expansion result in particular in varying thicknesses D.sub.Z of the cells 106.

[0260] In order to compensate for these fluctuations in expansion, the cooling elements 110 preferably take a flexible form such that if the cells 106 expand, the cooling elements 110 can preferably be compressed. As a result, reliable abutment and thus reliable heat transfer can be ensured even in the event of varying expansions of the cells 106.

[0261] Moreover, this preferably results in a reliable holding action for positioning the cells 106 between the cooling elements 110.

[0262] However, optimum cooling can only be ensured if coolant can always flow through the cooling elements 110.

[0263] For this purpose, the cooling elements 110 are preferably provided with spacers 202.

[0264] The spacers 202 take the form for example of projections or other bulges or indentations in the layers 114 of the cooling elements 110, and in the event of too great a compression of the respective cooling element 110 they come into abutment with the respectively opposing layer 114. The possibility that the two layers 114 will abut flat against one another can thus be prevented. In this way, it is also possible to effectively avoid the stream of coolant being interrupted.

[0265] As can be seen in particular from the schematic illustration in FIG. 6, the cell stack 102 further preferably includes a pumping device 204 by means of which a stream of coolant is configured to be driven through the cooling elements 110.

[0266] Further, a fluid pressurisation device 206 is preferably provided by means of which a pressure within the cooling elements 110 can be controlled by open and/or closed-loop control.

[0267] In particular, this enables the cooling elements 110 to abut reliably against the cells 106 without exerting too great a pressure on the cells 106.

[0268] Further, preferably a condition of the cells 106 can be determined by means of a measuring device 208.

[0269] For example, a quantity of coolant that is currently found within the cooling elements 110 can be determined by way of a equalisation tank 210 of the measuring device 208. It is possible to deduce from this quantity the current volume of the internal spaces 120 of the cooling elements 110 and thus the expansion of the cooling elements 110 and the cells 106.

[0270] The expansion of the cells 106 can in turn be utilised in particular in combination with further parameters such as the temperature and/or an internal cell pressure to determine a current condition of the cell 106.

[0271] As a result of the features described above of the electrical energy storage device 100, the cell stack 102 and/or the cooling module 112, preferably optimised cooling of the cells 106 and/or simplified construction and/or efficient and reliable operation of the entire device can be made possible.