Battery cell

Abstract

A battery cell (20) for an electric vehicle (10), comprising a housing (30), an electrode stack arrangement (50), a first conductor element (81), a second conductor element (82), a first connection element (38), and a second connection element (39). The electrode stack arrangement (50) is arranged in the housing (30) and comprises first electrode arrangements (51) and second electrode arrangements (52). The first electrode arrangements (51) comprise first electrodes (61) and first strip elements (55). The second electrode arrangements (52) comprise second electrodes (62) and second strip elements (56). The housing (30) has a cuboidal basic shape with a first housing side (31), a second housing side (32), a third housing side (33), a fourth housing side (34), a fifth housing side (35), and a sixth housing side (36). The first housing side (31) is provided opposite the second housing side (32).which third housing side (33) is provided opposite to the fourth housing side (34), which fifth housing side (35) is provided opposite to the sixth housing side (36), which first housing side (31) and second housing side (32) are each smaller than the third housing side (33) and than the fourth housing side (34), , which first electrodes (61) and second electrodes (62) extend at least partially parallel to the fifth housing side (35), which first connection element (38) and which second connection element (39) are electrically conductive and can be contacted from an outer side (22) of the housing (30), which first strip elements (55) on the side of the first electrodes (61) facing the third housing side (33) are electrically connected to the first conductor element (81), which first conductor element (81) is electrically connected to the first connection element (38), and which first connection element (38) is provided on the first housing side (31), which second strip elements (56) on the side of the second electrodes (62) facing the fourth housing side (34) are electrically connected to the second conductor element (82), which second conductor element (82) is electrically connected to the second connection element (39), and which second connection element (39) is provided on the second housing side (32) or on the first housing side (31), and which fifth housing side (35) and which sixth housing side (36) are each larger than the third housing side (33) and than the fourth housing side (34).

Description

The invention relates to a battery cell.DE 10 2013 206 627 A1 discloses a lithium-ion accumulator having a housing, a cover, a positive and negative current collector and two current collectors provided on the cover.DE 10 2012 204 595 A1 shows an arrangement for carrying out a current path through a housing of a battery cell.US 2006 / 040 176 A1 shows a prismatic battery cell in which the electrode groups are each connected to a terminal via a current collector.EP 2 681 783 B1 shows a primary battery with an integrated housing electronic board supplied by the battery, which is connected to inner and outer connection terminals.U.S. Pat. No. 2016 / 0 056 497 A1 shows a battery cell having an electrode stack, a positive conductor for contacting the positive electrodes, a negative conductor for contacting the negative electrodes, and a housing, wherein the electrodes with the positive and negative conductors are arranged in the housing.DE 11 2007 002 406 T5 discloses a method for producing a collector and an electrical power storage device, wherein the collector has a thickness which decreases with increasing distance from a connection protrusion.DE 10 2012 211 653 A1 discloses an energy storage module having stacked prismatic storage cells and having an insulation film.It is therefore an object of the invention to provide a novel battery cell.The object is achieved by the subject matter of claim 1.A battery cell for an electric vehicle has a housing, an electrode stack arrangement, a first conductor element, a second conductor element, a first connection element and a second connection element, which electrode stack arrangement is arranged in the housing and has first electrode arrangements and second electrode arrangements, which first electrode arrangements have first electrodes and first strip elements, which second electrode arrangements have second electrodes and second strip elements, which housing has a cuboidal basic shape having a first housing side, a second housing side, a third housing side, a fourth housing side, a fifth housing side and a sixth housing side, which first housing side is provided opposite the second housing side, which third housing side is provided opposite the fourth housing side, which fifth housing side is provided opposite the sixth housing side, which first housing side and second housing side are each smaller than the third housing side and than the fourth housing side, which first connection element and which second connection element are designed to be electrically conductive and can be contacted by an outer side of the housing, which first strip elements are electrically connected to the first conductor element on the side of the first electrodes facing the third housing side, which first conductor element is electrically connected to the first connection element, and which first connection element is provided on the first housing side, which second strip elements are electrically connected to the second conductor element on the side of the second electrodes facing the fourth housing side, which second conductor element is electrically connected to the second connection element, and which second connection element is provided on the second housing side or on the first housing side.This battery cell enables a comparatively small current path within the electrode and low-loss transmission of the current via the conductor elements. The arrangement of the connection elements on the smaller housing sides enables a compact design and good cooling, in particular also on the larger housing sides. The entire battery cell is advantageous with regard to heat generation and cooling and with regard to the installation space requirement by this combination. This allows a long range when used in an electric vehicle and the cooling system may have less cooling capacity than other solutions.The fifth housing side and the sixth housing side are respectively larger than the third housing side and the fourth housing side. This results in an optimization between stack thickness, arrangement of the strip elements and cooling.According to a preferred embodiment, the first conductor element forms the third housing side at least in sections, and the second conductor element forms the fourth housing side at least in sections. This reduces the installation space and the weight of the battery cell.According to a preferred embodiment, the first conductor element extends to the side of the electrode stack arrangement facing the first housing side, and the second conductor element extends to the side of the electrode stack arrangement facing the second housing side.According to a preferred embodiment, the third housing side has a first length between the first housing side and the second housing side, and the first conductor element extends on the side of the first electrodes facing the third housing side between the first housing side and the second housing side over a second length, which second length is at least 50% of the first length, preferably at least 60%, more preferably at least 70% and particularly preferably at least 80%. This enables contacting of the strip elements over a long region.According to a preferred embodiment, the first electrodes have a third length between the first housing side and the second housing side, and the first strip elements are electrically connected to the first conductor element between the first housing side and the second housing side over a fourth length on the side of the first electrodes facing the third housing side, which fourth length is at least 60% of the third length, preferably at least 70%, more preferably at least 80% and particularly preferably at least 90%. The current can thereby flow to the conductor element over a wide range.According to a preferred embodiment, the first conductor element increases in cross section at least in sections in its course in the direction of the first connection element, and the second conductor element increases in cross section at least in sections in its course in the direction of the second connection element. The cross-sectional increase can be effected, for example, by changing the thickness, the width and the shape. The current flowing in the conductor element increases in the direction of the connection element, and the larger cross section leads to a lower electrical resistance and thus to a lower generation of heat.According to a preferred embodiment, the first conductor element forms the first connection element. According to a preferred embodiment, the second conductor element forms the second connection element. This enables an additional electrical connection between the conductor element and the connection element to be eliminated or simplified.The first electrodes and the second electrodes extend at least in sections parallel to the fifth housing side. This leads to good utilization of the space present in the housing.According to a preferred embodiment arethe fifth housing side,the sixth housing side, orthe fifth housing side and the sixth housing side in each case at least in sections electrically insulated from the first connection element and the second connection element.The safety of the battery cell with respect to undesired electrical connections is thereby increased.According to a preferred embodiment, the third housing side, the fourth housing side, the fifth housing side and the sixth housing side are electrically insulated on the outer side. This increases the safety of the battery cell against short circuits.According to a preferred embodiment, a planar insulation material is provided on the outside on the fifth housing side, which material has an adhesive layer on both surfaces. Preferably, a planar insulation material is also provided on the outside on the sixth housing side, which material has an adhesive layer on both surfaces. Such an electrical insulation material enables a mechanical connection between the battery cells and reduces the risk of a short circuit.According to a preferred embodiment, a battery arrangement comprises battery cells according to one of the preceding claims. Such a battery arrangement produces comparatively little waste heat and can be cooled well.Further details and advantageous developments of the invention are evident from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, and from the dependent claims. It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention. It shows: FIG. 1 shows a schematic three-dimensional illustration of a battery cell, FIG. 2 shows a longitudinal section of the battery cell from FIG. 1, FIG. 3 shows an electrode arrangement in a side view, FIG. 4 shows a plan view of the electrode arrangement of FIG. 3, and FIG. 5 shows a cross section of the battery cell of FIG. 5 . 1In the following, identical or identically acting parts are provided with the same reference symbols and are usually described only once. The description is based on one another across the figures in order to avoid unnecessary repetitions.FIG. 1 shows a schematic three-dimensional illustration of a battery cell 20 for a battery arrangement 12, which can preferably be used in an electric vehicle 10.The battery cell 20 has a housing 30 with a cuboidal basic shape. The housing 30 has a first housing side 31 (left), a second housing side 32 (right), a third housing side 33 (top), a fourth housing side 34 (bottom), a fifth housing side 35 (front) and a sixth housing side 36 (rear). The orientations indicated in brackets refer to the location in the figure and are exemplary.The first housing side 31 is provided opposite the second housing side 32, the third housing side 33 is provided opposite the fourth housing side 34, and the fifth housing side 35 is provided opposite the sixth housing side 36.The first housing side 31 and the second housing side 32 are preferably smaller than the third housing side 33 and than the fourth housing side 34, respectively.The fifth housing side 35 and the sixth housing side 36 are preferably respectively larger than the third housing side 33 and than the fourth housing side 34.In other words, the side lengths of the housing 30 in the different spatial directions are preferably of different sizes, wherein the length between the first housing side 31 and the second housing side 32 is preferably the greatest, the length between the third housing side 33 and the fourth housing side 34 is smaller, and the length between the fifth housing side 35 and the sixth housing side 36 is preferably even smaller.The battery cell 20 has a first connection element 38 and a second connection element 39.The first connection element 38 and the second connection element 39 are designed to be electrically conductive and can be contacted from an outer side 22 of the housing 30.The first connection element 38 is provided on the first housing side 31 and the second connection element 39 is provided on the second housing side 32. Alternatively, the second connection element 39 can likewise be provided on the first housing side 31. For the alternative embodiment, the connection elements 38, 39 are preferably smaller than shown.FIG. 2 shows a longitudinal section of the battery cell 20 from FIG. 1.An electrode stack assembly 50 is disposed in the housing 30, and includes first electrode assemblies 51 and second electrode assemblies 52. The first electrode arrangements 51 have first electrodes 61 and first strip elements 55, and the second electrode arrangements 52 have second electrodes 62 and second strip elements 56, cf. also FIG. 5.The battery cell 20 has a first conductor element 81 and a second conductor element 82.In the exemplary embodiment, the first conductor element 81 extends on the third housing side 33 and also on the first housing side 31. The second conductor element 82 extends in the exemplary embodiment on the fourth housing side 34 and also on the second housing side 32.The first strip elements 55 are electrically connected to the first conductor element 81 on the side of the first electrodes 61 facing the third housing side 33, and the first conductor element 81 is electrically connected to the first connection element 38.The second strip elements 56 are electrically connected to the second conductor element 82 on the side of the second electrodes 62 facing the fourth housing side 34, and the second conductor element 82 is electrically connected to the second connection element 39.The first conductor element 81 is provided with an electrical insulation layer 330 and the second conductor element 82 is provided with an electrical insulation layer 340. The electrical insulation layers 330, 340 can be, for example, lacquer layers or an insulation material, preferably made of plastic, and further preferably with adhesive layers on both surfaces. This allows good stacking of the battery cells with an insulation function.In the exemplary embodiment, the first conductor element 81 forms the third housing side 33 at least in sections or completely, and the second conductor element 82 forms the fourth housing side 34 at least in sections or completely. The conductor elements 81, 82 can thus assume a plurality of functions. Alternatively, an additional housing part-not shown-can be provided on the third housing side 33 and on the fourth housing side 34, in order to achieve, for example, insulation or a lower mass.In the exemplary embodiment, the first conductor element 81 extends to the side of the electrode stack arrangement 50 facing the first housing side 31, and the second conductor element 82 extends to the side of the electrode stack arrangement 50 facing the second housing side 32.The third housing side 33 has a length L 1 between the first housing side 31 and the second housing side 32, and the first conductor element 81 extends on the side of the first electrodes 61 facing the third housing side 33 between the first housing side 31 and the second housing side 32 over a second length L 2, which second length L 2 is preferably at least 50% of the first length L 1, further preferably at least 60%, further preferably at least 70% and particularly preferably at least 80%. This allows the strip elements 55 to be contacted over a long length. The same applies preferably to the second conductor element 82 in relation to the fourth housing side 34.The first electrodes 61 have a third length L 3 between the first housing side 31 and the second housing side 32, and the first strip elements 55 are preferably electrically connected to the first conductor element 81 between the first housing side 31 and the second housing side 32 over a fourth length L 4 on the side of the first electrodes 61 facing the third housing side 33, which fourth length L 4 is preferably at least 60% of the third length L 3, more preferably at least 70%, more preferably at least 80% and particularly preferably at least 90%. In the exemplary embodiment, the ratio is 100%, and the lengths L 3 and L 4 are therefore the same. As a result of this configuration, an electrical connection between the first electrodes 61 and the first conductor element 81 is present over a long length, and this leads to a low electrical resistance or to a low internal resistance of the battery cell 20. Since the area of the third housing side 33 is larger than the area of the first housing side 31, the contacting on the third housing side 33 enables short paths of the current from the first electrodes 61 via the strip elements 55 to the conductor element 81.The same applies preferably to the length of the connection of the strip elements 56 relative to the length of the second electrodes 62 on the side of the second electrodes 62 facing the fourth housing side 34.Preferably, the first conductor element 81 increases in cross section at least in sections in its course in the direction of the first connection element 38, and the second conductor element 82 increases in cross section at least in sections in its course in the direction of the second connection element 38. Since the current flowing in the conductor elements 81, 82 increases toward the terminals 38 and 39, a decrease in the electrical resistance can be achieved on the one hand, and a smaller cross section and thus a lower weight can nevertheless be achieved in the sections with a low current on the other hand. In the exemplary embodiment, the cross section is achieved by increasing the thickness of the conductor elements 81, 82.Preferably, the first conductor element 81 forms the first connection element 38 and the second conductor element 82 forms the second connection element 39. It is therefore not necessary to produce additional connections between conductive elements.The first electrodes 61 and second electrodes 62 preferably extend at least in sections parallel to the fifth housing side 35 and thus also to the sixth housing side 36 This results in a short path of the strip elements 55, 56 to the conductor elements 81, 82.Schematically depicted is an adjacent battery cell 20' of the battery arrangement 12, which is preferably electrically insulated with respect to the battery cell 20. This increases safety.FIG. 3 shows a side view of an electrode arrangement 51 or 52, which has an electrode 61 or 62 and a strip element 55 or 56. Strip elements 55, 56 of this type are referred to in English as "tab" and serve for contacting the electrode 61 or 62.The electrodes 61 and 62 respectively have a longitudinal direction 91 and a transverse direction 92 transversely to the longitudinal direction 91.FIG. 4 shows a schematic plan view of the electrode arrangement 51, 52 from FIG. 3.The electrode arrangement 51 or 52 has a foil 53 which is also referred to as a conductor foil and permits a current flow as an electrical conductor. In the region of the electrode 61, 62, an active material layer 54 is provided on one side of the foil 53 or on both sides. The thickness 93 of the electrode 61, 62 is preferably in the range of 15 μm to 2 mm.Strip element 55 or 56 is preferably at least partially or completely free of active material layer 54, since this region is not effective for the galvanic cell on the one hand and is also usually less electrically conductive than film 53 on the other hand. In addition, strip element 55 or 56 without active material layer 54 has a smaller thickness 94 than in the region of electrode 61 or 62, and this enables better bending of strip element 55 or 56 and a more compact construction in the contact-making region with associated connection element 38 or 39.The thickness 94 is preferably in the range of 4 μm to 50 μm.The battery cell is preferably designed as a lithium-ion battery cell.Here, the positive electrode assembly 51 preferably includes a foil 53 made of aluminum or made of an aluminum alloy, and the active material layer 54 preferably includes an active material such aslithium cobalt(III) oxide,lithium nickel manganese cobalt oxide,lithium nickel cobalt aluminum oxide, orlithium iron phosphate.The negative electrode arrangement 52 preferably has a foil 53 made of copper or made of a copper alloy, and the active material layer 54 preferably has an active material such asgraphite,nanocrystalline, amorphous silicon,lithium titanate, ortin dioxide.The active material layers 54 can each additionally comprise additives.The battery cell 20 can also be constructed as another cell type, for example assodium-sulfur battery cell,nickel-iron battery cell, ornickel-zinc battery cell.Preferably, the battery cell 20 is rechargeable, and such a battery cell 20 is also referred to as a secondary cell or secondary element.The electrode arrangement 51 can also be formed negative and the electrode arrangement 52 positive, so that the connection element 38 is negative and the connection element 39 is positive.FIG. 5 shows the battery cell 20 from above in a longitudinal section.An electrode stack assembly 50 is provided in the case 30, and the electrode stack assembly 50 includes the electrode assemblies 51 and the electrode assemblies 52. Separators 63 are preferably provided between the electrodes 61 of the electrode assemblies 51 and the electrodes 62 of the electrode assemblies 52. In the exemplary embodiment, electrodes 61 and electrodes 62 are always provided alternately. It is also possible to provide at least partially-for example in the middle-two identical electrodes 61 or two identical electrodes 62 adjacent to one another.An electrolyte 64 is also provided in the housing 30 in order to allow ion flow.The electrodes 61 and 62 extend in their longitudinal direction 91 between the housing side 33 and the housing side 34. the longitudinal direction 91 can thus be defined relative to the housing sides 33, 34. Alternatively, the longitudinal direction 91 can be defined relative to the conductor elements 81, 82, to which the strip elements 55, 56 are conductively fastened. Preferably, all electrodes 61, 62 extend in the same longitudinal direction 91. the longitudinal direction 91 can, however, also be at least partially somewhat different. The strip elements 55 of the electrode arrangements 51 are positioned on the side associated with the housing side 33, and the strip elements 56 are positioned on the side associated with the housing side 34.The first conductor member 81 is electrically connected to the electrodes 61 via the strip members 55, and the second conductor member 82 is electrically connected to the electrodes 62 via the strip members 56. Here, a first plurality 551 of the first strip members 55 and a second plurality 552 of the first strip members 55 are connected to the first conductor member 81, and a second plurality 561 of the second strip members 56 and a second plurality 562 of the second strip members 56 are connected to the second conductor member 82.The housing 30 has a housing wall 41 on the housing side 33 and a housing wall 42 on the housing side 34, The housing walls 41, 42 and the housing sides 35, 35 are designed to be electrically non-conductive in the exemplary embodiment. Alternatively, the housing walls 41, 42 can be conductive and formed as part of the conductor elements 81, 82, cf. FIG. 2.Of course, within the scope of the present invention, numerous modifications and variations are possible.

Claims

Battery cell (20) for an electric vehicle (10), which has a housing (30), an electrode stack arrangement (50), a first conductor element (81), a second conductor element (82), a first connection element (38) and a second connection element (39), which electrode stack arrangement (50) is arranged in the housing (30) and has first electrode arrangements (51) and second electrode arrangements (52), which first electrode arrangements (51) have first electrodes (61) and first strip elements (55), which second electrode arrangements (52) have second electrodes (62) and second strip elements (56), which housing (30) has a cuboidal basic shape with a first housing side (31), a second housing side (32), a third housing side (33), a fourth housing side (34), a fifth housing side (35) and a sixth housing side (36), which first housing side (31) is provided opposite the second housing side (32), which third housing side (33) is provided opposite the fourth housing side (34), which fifth housing side (35) is provided opposite the sixth housing side (36), which first housing side (31) and second housing side (32) are each smaller than the third housing side (33) and than the fourth housing side (34), which first electrodes (61) and second electrodes (62) extend at least in sections parallel to the fifth housing side (35), which first connection element (38) and which second connection element (39) are designed to be electrically conductive and can be contacted by an outer side (22) of the housing (30), which first strip elements (55) are electrically connected to the first conductor element (81) on the side of the first electrodes (61) facing the third housing side (33), which first conductor element (81) is electrically connected to the first connection element (38), and which first connection element (38) is provided on the first housing side (31), which second strip elements (56) are electrically connected to the second conductor element (82) on the side of the second electrodes (62) facing the fourth housing side (34), which second conductor element (82) is electrically connected to the second connection element (39), and which second connection element (39) is provided on the second housing side (32) or on the first housing side (31), and which fifth housing side (35) and which sixth housing side (36) are each larger than the third housing side (33) and than the fourth housing side (34).Battery cell (20) according to Claim 1, in which the first conductor element (81) forms the third housing side (33) at least in sections, and in which the second conductor element (82) forms the fourth housing side (34) at least in sections.Battery cell (20) according to one of the preceding claims, in which the first conductor element (81) extends to the side of the electrode stack arrangement (50) facing the first housing side (31), and in which the second conductor element (82) extends to the side of the electrode stack arrangement (50) facing the second housing side (32).Battery cell (20) according to one of the preceding claims, in which the third housing side (33) has a first length (L1) between the first housing side (31) and the second housing side (32), and in which the first conductor element (81) extends between the first housing side (31) and the second housing side (32) over a second length (L2), on the side of the first electrodes (61) facing the third housing side (33), which second length (L2) is at least 50% of the first length (L1), preferably at least 60%, further preferably at least 70% and particularly preferably at least 80%.Battery cell (20) according to one of the preceding claims, in which the first electrodes (61) between the first housing side (31) and the second housing side (32) have a third length (L3), and in which the first strip elements (55) on the side of the first electrodes (61) facing the third housing side (33) are electrically connected to the first conductor element (81) between the first housing side (31) and the second housing side (32) over a fourth length (L4), which fourth length (L4) is at least 60% of the third length (L3), preferably at least 70%, further preferably at least 80% and particularly preferably at least 90%.Battery cell (20) according to one of the preceding claims, in which the first conductor element (81) increases in cross section at least in sections in its course in the direction of the first connection element (38), and in which the second conductor element (82) increases in cross section at least in sections in its course in the direction of the second connection element (39).Battery cell (20) according to one of the preceding claims, in which the first conductor element (81) forms the first connection element (38), and in which preferably the second conductor element (82) forms the second connection element (39).Battery cell (20) according to one of the preceding claims, in which - the fifth housing side (35), - the sixth housing side (36), or - the fifth housing side (35) and the sixth housing side (36) are electrically insulated, at least in sections, in each case with respect to the first connection element (38) and the second connection element (39).Battery cell (20) according to one of the preceding claims, in which the third housing side (33), the fourth housing side (34), the fifth housing side (35) and the sixth housing side (36) are electrically insulated on the outer side.Battery cell (20) according to one of the preceding claims, in which a planar insulation material is provided on the outside on the fifth housing side (35), which material has an adhesive layer on both surfaces.A battery arrangement (12) comprising battery cells (20) according to any preceding claim.

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