NL2017013B1 - Battery cell stack, battery comprising a battery cell stack, and method for assembling a battery cell stack - Google Patents

Abstract

The present invention relates to a battery cell stack and a battery, in particular a secondary battery, comprising a battery cell stack, and a method for assembling a battery cell stack. The battery cell stack according to the present invention comprises a stack of battery cells, each battery cell comprising a positive tab and a negative tab; at least one stack of clamp bars arranged adjacent the stack of battery cells; a clamping mechanism acting on the at least one stack of clamp bars at opposite ends of the at least one stack of clamp bars for clamping the clamp bars against each other; wherein of each pair of neighbouring battery cells the positive tab of one of the pair of battery cells and the negative tab of the other one of the pair of battery cells are clamped against each other between a pair of neighbouring clamp bars.

Description

Patent center

The Netherlands

(21) Application number: 2017013 © Application submitted: 20/06/2016

Θ 2017013

BI PATENT @ Int. CL:

H01M 2/10 (2016.01) H01M 2/20 (2016.01) H01M 10/04 (2016.01)

(Tl) Application registered: (73) Patent holder (s): 04/01/2018 EST-Floattech B.V. in Medemblik. (43) Application published: - (72) Inventor (s): Marc Bertram van der Raaij in Medemblik. (D) Patent granted: 04/01/2018 (74) Agent: (45) Patent issued: ir. P.J. Hylarides et al. In The Hague. 31/01/2018

Battery cell stack, battery comprising a battery cell stack, and a method for assembling a battery cell stack © The present invention relates to a battery cell stack and a battery, in particular a secondary battery, including a battery cell stack, and a method for assembling a battery cell stack.

The battery cell stack according to the present invention comprises a stack of battery cells, each battery cell including a positive tab and a negative tab; at least one stack of clamp bars arranged adjacent the stack of battery cells; a clamping mechanism acting at the least one stack of clamp bars at opposite ends of the at least one stack of clamp bars for clamping the clamp bars against each other; either of each pair of neighboring battery cells the positive tab or one of the pair of battery cells and the negative tab of the other one of the pair of battery cells are clamped against each other between a pair of neighboring clamp bars.

NL BI 2017013

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

Battery cell stack, battery including a battery cell stack, and method for assembling a battery cell stack

The present invention relates to a battery cell stack and a battery, in particular a secondary battery, including a battery cell stack, and a method for assembling a battery cell stack.

Secondary batteries including a battery cell stack are known. In such batteries the battery cell stack comprises a stack of individual secondary battery cells, each battery cell having a positive tab and a negative tab. The positive tabs and negative tabs of the individual battery cells are electrically connected in series or in parallel, in particular by means of electrical connection elements. The electrical connection between the tabs of the individual cells influences the performance of the battery cell stack, and thus the battery, both during charging of the battery as well as during discharging of the battery when using the battery as a power source.

The battery cell stack according to the present invention comprises:

- a stack of battery cells, each battery cell including a positive tab and a negative tab;

- at least one stack of clamp bars arranged adjacent the stack of battery cells;

- a clamping mechanism acting on the least one stack of clamp bars on opposite ends of the at least one stack of clamp bars for clamping the clamp bars against each other;

will

- or each pair of neighboring battery cells the positive tab or one of the pair of battery cells and the negative tab of the other one of the pair of battery cells are clamped against each other between a pair of neighboring clamp bars.

In the battery cell stack according to the invention, the tabs of neighboring battery cells, in particular secondary battery cells, are in direct contact. Electrical connection elements for connecting the tabs are omitted such that the transition resistance between the tabs is reduced. This has a positive influence on the performance of the battery cell stack, and thus the battery, both during charging of the battery as well as during discharging of the battery when using the battery as a power source.

Furthermore, since the clamping mechanism acts at the least one stack of clamp bars at opposite ends of the at least one stack of clamp bars for clamping the clamp bars against each other, the clamp bars or the least one stack of clamp bars apply the same clamping force on each pair of tabs that are clamped between the clamp bars or the least one stack of clamp bars. This contributes to the aim of having as equal as possible connection characteristics for each electrical connection between tabs of the individual battery cells. Having as equal as possible connection characteristics for each electrical connection between tabs of the individual battery cells has a positive influence on the performance of the battery cell stack, and thus the battery, both during charging of the battery as well as during discharging of the battery when using the battery as a power source. Still further, the battery cell stack according to the present invention is as a result of the use of at least one stack of clamp bars arranged adjacent the stack of battery cells particularly easy to assemble, as explained in the description to the figures under reference to figures 5 to 13.

In a preferred embodiment of the battery cell stack according to the invention:

- extend the clamped parts of the tabs in parallel planes;

- the clamping mechanism is configured to exert a clamping force on the stack of clamp bars perpendicular to the planes.

In an advantageous embodiment of the battery cell stack according to the invention the clamping mechanism comprises at least one spring member arranged at least one end of the at least one stack of clamp bars. Having a spring member arranged at least one end of the least one stack of clamp bars allows for compensating for change of material properties of the components of the clamping mechanism as a result of temperature differences or as a result of being under load for a long period of time, which change of material properties may result in an undesired change of the clamping force by means of which the tabs are clamped against each other. This has the advantage that a desired clamping force can be maintained over time.

In a preferred embodiment the least one spring member includes a leave spring member. Alternatively, the least one spring member includes a coil spring or cantilever spring.

In an advantageous embodiment of the battery cell stack according to the invention each two clamp bars having a positive tab and negative tab clamped there between are mutually coupled in a direction perpendicular to the least one stack of clamp bars by at least one coupling arrangement.

In a preferred embodiment of the at least one coupling arrangement includes at least one rod extending through the stacked clamp bars. Preferably, the least one coupling arrangement includes at least two parallel arranged rods extending through the stacked clamp bars. In an advantageous embodiment of the least one rod extending through the stacked clamp bars extended between opposite ends of the least one stack of clamp bars and being connected at the opposite ends of the least one stack of clamp bars to a frame on which the clamp bars are arranged. Preferably, at least two parallel arranged rods extend through the stacked clamp bars between the opposite ends of the one stack of clamp bars and are each connected at the opposite ends of the stack of clamp bars to the frame.

In a further advantageous embodiment of the battery cell stack according to the invention as described above, the battery cell stack comprises a first stack of clamp bars and a second stack of clamp bars, subject of each battery cell one of the positive tab and the negative tab is clamped between two neighboring clamp bars or the first stack of clamp bars and the other one of the positive tab and the negative tab is clamped between two neighboring clamp bars or the second stack of clamp bars. These features allow for a particular advantageous assembly of the battery cell stack according to the invention as explained in the description to the figures under reference to figures 5 to 13. In a preferred embodiment the first stack of clamp bars and the second stack of clamp bars extend in the same plane.

In an advantageous embodiment the clamp bars or the first stack of clamp bars and the clamp bars or the second stack of clamp bars are offset in the stacking direction, preferably offset by half the height or one clamp bar measured in the stacking direction. This has the advantage that the distance between the battery cell and the location where the positive tab is clamped between two clamp bars is about the same as the distance between the battery cell and the location where the negative tab is clamped between two clamp bars.

In a further advantageous embodiment the clamp bars or the first stack of clamp bars and the clamp bars or the second stack of clamp bars are arranged end-to-end. In a preferred embodiment of the end-to-end arranged clamp bars have complementing rebated edge regions at their meeting ends. In a particular advantageous embodiment in combination with the feature of having at least one rod extending through the at least one stack of clamp bars, at least one rod extending through the complementing rebated edge regions or the stacked clamp bars.

In a further advantageous embodiment of the battery cell stack according to the invention each battery cell is arranged between two separation sheets, which separation sheets are at the end that is near the positive tab and negative tab of the battery cell coupled to a frame on which the clamp bars are arranged, and which sheets are arranged at the opposite end associated with at least one spacer element arranged between the sheets, arranged at least one spacer element is arranged such that it supports the battery cell along the edge positive tab and negative tab. This feature allows for the stack of battery cells to hang from the frame without the clamped tabs bearing the weight of the battery cells. In a preferred embodiment, at least one separation sheet extends at the end that is near the positive tab and negative tab of the battery cell at least one slot that is arranged at least one clamp bar, and is coupled to the at least one clamp bar via a rod extending into the slot and through a hole in the separation sheet. Advantageously, the rod extends between opposite ends of the least one stack of clamp bars, and extends through the stacked clamp bars and through the hole of each of the separation sheets that extend in one of the slots in one of the clamp bars, and is connected at the opposite ends or at least one stack of clamp bars to which the clamp bars are arranged.

In a further advantageous embodiment of the battery cell stack according to the invention at least one of the opposing clamping faces or neighboring clamp bars between which the positive tab and negative tab or neighboring battery cells are clamped is provided with a conductive element that is at one end thereof in conductive contact with one of the positive tab and negative tab and that is at another end as configured as an electrical connector. The conductive element allows for connecting to the tabs a battery management system that for instance by measuring electrical quantities at each pair of clamped tabs via a respective conductive element can monitor the state of each individual battery cell.

In a preferred embodiment of the battery cell stack according to the invention the battery cells are flat and rectangular, and have along one edge of the positive tab and the negative tab.

The present invention further relates to a battery, including:

- a battery cell stack according to the invention as described above;

- a container having a closed bottom and an open top; and

- a member for closing the open top of the container; will

- the least one stack of clamp bars and the clamping mechanism are arranged near the open top of the container and the ends of the battery cells opposite the positive and negative tabs extend towards the bottom of the container.

In a preferred embodiment:

- the least one stack of clamp bars and the clamping mechanism are arranged on a frame;

- the battery cell stack is coupled to the container near the open top through the frame; and

- the battery cell stack is coupled to the container near the bottom via a layer of cured resin in which the ends of the battery cells opposite the positive and negative tabs are submerged.

The present invention further relates to a method for assembling a battery cell stack, in particular a battery cell stack according to the invention as described above, including the steps of:

- making a stack of battery cells each battery cell including a positive tab and a negative tab;

- arranging at least one stack of clamp bars adjacent the stack of battery cells;

- arranging each pair or neighboring battery cells the positive tab or one of the pair of battery cells and the negative tab or the other one of the pair of battery cells in between two neighboring clamp bars;

- applying a clamping force on the least one stack of clamp bars at opposite ends of the least one stack of clamp bars for clamping the clamp bars against each other, clamping the positive tabs and negative tabs that are arranged between neighboring clamp bars against each other.

In a preferred embodiment, while making a stack of battery cells arranging at least one stack of clamp bars adjacent the stack of battery cells, any time after a next battery cell is stacked on a previous battery cell, the positive tab of one of the previous and next battery cells and the negative tab of the other one of the previous and next battery cells are arranged on top of each other on a previous clamp bar or at least one stack of clamp bars, and a next clamp bar is arranged on top of the positive tab and the negative tab such that the positive tab and the negative tab are arranged in between the previous clamp bar and the next clamp bar.

The present invention is further elucidated in the following description with reference to the accompanying schematic figures, in which:

Figure 1 shows a battery according to the invention in perspective view;

Figure 2 shows the battery or Figure 1 in perspective view with parts tasks away in order to show the battery cell stack inside the battery;

Figure 3 shows the battery cell stack or Figure 2 in perspective view;

Figure 4 shows the battery cell stack or Figure 2 in exploded view;

Figures 5 to 13 show steps or an embodiment of the method for assembling the battery cell stack or figure 2.

Figures 1 and 2 show a battery 1. The battery 1 has a container 3 having a bottom wall 5 and four side walls 7 extending from the bottom wall 5. The edges of the side walls 7 opposite to the bottom wall 5 together from the circumferential edge 9 of an opening 11 of the container 3. The container 3 thus has a closed bottom 3a and an open top 3b. The open top 3b is closed by a member 13. The member 13 has a circumferential flange 15 that is arranged on a circumferential flange 17 of the circumferential edge 9 of the opening 11. The member 13 and the container 3 are coupled by means of fasteners 19 that fasten the flange 17 of the container 3 to the flange 15 of the lid 13. A seal 19 is arranged between flange 15 and flange 17.

In the container 3 is arranged a battery cell stack 21. In the container 3 is also arranged a circuit board assembly 23 that is part of a battery management system for the battery cell stack 21.

Arranged on the member 13 are two main connectors, a positive main connector 25 and a negative main connector 27. The positive main connector 25 is electrically connected inside the container 3 to a positive terminal 29 or the battery cell stack 21 via a positive lead ( not shown). The negative main connector 27 is electrically connected inside the container 3 to a negative terminal 31 or the battery cell stack 21 via a negative lead (not shown). The positive main connector 25 and a negative main connector 27 are configured for electrically connecting the battery cell stack 21 to electrical components or an electrical system. Arranged on the lid 13 are two battery management connectors 33.35 that are electrically connected inside the container 3 to the circuit board assembly 23. The battery management connectors 33, 35 are configured for electrically connecting the battery cell stack 21 to components of a battery management subsystem of the electrical system to which the battery cell stack 21 is connected via the main connectors 25, 27.

In figure 3 the battery cell stack 21 is shown with the paragraph 17, the container 3 and the circuit board assembly 23 removed. Figure 3 shows the battery cell stack 21 is at its upper end 21a provided with a frame 37 that has two flanged frame elements 39, 41. Figure 2 shows the flanged frame elements 39, 41 are supported by the side walls 7 of the container and are more in particular arranged on the flange 17 of the circumferential edge 9 of the container 3. The lower end 21b of the battery cell stack is arranged in the container 3 and is located near the bottom wall 5 of the container 3. As shown in figure 2, the battery cell stack 21 is coupled to the container 3 near the bottom wall 5 through a layer 43 or cured resin in which the lower end 21b or the battery cell stack 21 is submerged.

Figure 3 shows that when the circuit board assembly 23 or the battery management system is removed, battery management terminals 45 are revealed that electrically connect the battery cells or the battery cell stack 21 to the circuit board assembly 23 or the battery management system, as will be explained in more detail below below reference to figures 5 to 13.

In figure 4 an exploded view is shown of the battery cell stack 21 that is shown in figure 3. In figures 3 and 4 the battery cell stack 21 is shown having fourteen battery cells 47. The battery cells 47 are flat and have a substantially rectangular front face 47a and rear face 47b. Each battery cell 47 has a positive tab 49 and the negative tab 51 that are arranged along one edge or the front and rear face. The battery cells 47 are stacked such that or each pair of neighboring battery cells the front face or rear face of one of the pair of battery cells 47 faces the front face or rear face of the other one of the pair of neighboring battery cells 47. Each battery cell 47 is arranged between two separation sheets 53.

The battery cells 47 are oriented in the stack of battery cells 47 such that for each pair of neighboring battery cells 47, the positive tab 49 or one of the pair of battery cells 47 neighbor the negative tab 51 or the other one of the pair of battery cells 47. As shown in figure 4, as a result, there are two rows 55, 57 or tabs 47, which rows 55, 57 extend parallel to each other in the stacking direction A, each row 55, 57 has altematingly positive tabs 49 and negative tabs 51.

Arranged adjacent the stack 59 or battery cells 47, there are two stacks 61, 63 or clamp bars 65. Either two neighboring battery cells 47 or the stack 59 or battery cells 47, one of the tabs 49, 51 or one of the two battery cells 47 and one of the tabs 49, 51 of the other one of the two battery cells 47 are clamped against each other between a pair of neighboring clamp bars 65 of the first stack 61 or clamp bars or between a pair of neighboring clamp bars 65 or the second stack 63 or clamp bars. The first stack 61 or clamp bars 65 is associated with the first row 55 or tabs 49, 51. Each pair of neighboring clamp bars 65 or the first stack 61 or clamp bars 65 has clamped there between a positive tab 49 and a neighboring negative tab 51 or the first row 55 or tabs 49, 51. The second stack 63 or clamp bars 65 is associated with the second row 57 or tabs 49, 51. Each pair of neighboring clamp bars 65 or the second stack 63 or clamp bars has clamped there between a positive tab 49 and a neighboring negative tab 51 or the second row 55 or tabs 49.51.

Thus, the battery cells 47 or the stack 59 or battery cells 47 are electrically connected in series.

The positive tab 49 of the final battery cell 47 at the first end 59a of the stack 59 of battery cells 47 is clamped between the final clamp bar 65a of the first stack 61 of clamp bars 65 at the first end 61a of the first stack 61 or clamp bars and a first end bar 67. The final clamp bar 65a or the first stack 61 or clamp bars has a recess 69 or a part of the positive terminal 29 is arranged, such that the positive tab 49 or the final battery cell 47 at the first end 59a of the stack 59 of battery cells 47 is clamped against the part of the positive terminal 29 that is arranged in the recess 69. The positive tab 49 of the final battery cell 47 at the first end 59a of the stack 59 or battery cells 47 is thus electrically connected to the positive terminal 29.

The negative tab 51 of the final battery cell 47 at the second end 59b of the stack 59 of battery cells 47 is clamped between the final clamp bar 65b of the first stack 61 of clamp bars 65 at the second end 59b of the first stack 59 or clamp bars and a neighboring previous clamp bar 65 or the first stack of clamp bars. The final clamp bar 65b or the first stack 61 or clamp bars 65 has a recess (not shown) or a part of the negative terminal 31 is arranged, such that the negative tab 51 or the final battery cell 47 at the second end 59b or the stack 59 of battery cells 47 is clamped against the part of the negative terminal 31 that is arranged in the recess. The negative tab 51 or the final battery cell 47 at the second end 59b or the stack 59 or battery cells 47 is thus electrically connected to the negative terminal 31.

As shown in figure 4, each clamp bar 65 and the first end bar 67 has a clamping face 73 that is provided with a conductive element 75, such that one of the opposing clamping faces or neighboring clamp bars 65 between which the positive tab 49 and negative tab 51 or neighboring battery cells 47 are clamped provided with the conductive element 75. The conductive element 75 is at one end in conductive contact with one of the positive tab 49 and negative tab 51 that are clamped between the neighboring clamp bars 65 , while the other end of the conductive element 75 embodies one of the battery management terminals 45 and is configured as an electrical connector.

Together with a first leaf spring element 79 and a second leaf spring element 81, the clamp bars 65, the first end bar 67 and a second end bar 71 are arranged on the frame 37. The frame 37 comprises the flanged frame elements 39, 41 that extend parallel to the clamp bars 65 and to the end bars 67, 77. The frame 37 further comprises two frame elements 83, 85 that extend perpendicular to the flanged frame elements 39, 41 and along opposite sides of the combined stacks 61, 63 or clamp bars 65. The frame elements 83, 85 have their sides facing the ends of the clamp bars 65 a C-shaped cross section. The ends of the clamp bars 65 are received between the legs of the C-shaped cross section.

The first leaf spring element 79 is arranged between the first flanged frame element 39 and the first end bar 67. The second leaf spring element 81 is arranged between the second flanged frame element 41 and the second end bar 71 that is arranged on the final clamp bars of the first stack 61 and second stack 63 or clamp bars. The first leaf spring element 79 and the second leaf spring element 81 are oriented such that the spring elements can be compressed in the stacking direction or the first and second stack 61, 63 or clamp bars 65. Both leaf springs 79, 81 have two spring parts, a first spring part located between the rods 87 and 89, and a second spring part located between the rods 89 and 91.

The clamp bars 65, the first end bar 67, the second end bar 71, and the flanged frame elements 39, 41 have holes 77 arranged through which holes 77 rods 87, 89, and 91 extend. The rods 87, 89, 91 are coupled at the ends to the flanged frame elements 39, 41, by means of a pull arrangement that allows to pull the flanged frame elements 39, 41 toward each other, including the rods 87, 89, 91 serve as tie rods. Here the pull arrangement is embodied by bolts 93 that engage a threaded axial hole in the rods 87, 89, 91. The bolts 93 extend through holes 77 in an end plate 95. The heads of the bolts 93 contact the end plate 95. By screwing the bolts 93 into the threaded holes in the rods 87, 89, 91, the end plates 95 are pushed against the flanged frame elements 39, 41, such that the flanged frame element 39 is pulled towards the flanged frame element 41. By pulling the flanged frame element 39 towards the flanged frame element 41, the first leaf spring element 79 and the second leaf spring element 81 are compressed. The clamp bars 65 arranged between the first leaf spring element 79 and the second leaf spring element 81 are clamped against each other by means of the compression force that results from compressing the first leaf spring element 79 and the second leaf spring element 81. Each pair or positive tab 49 and negative tab 51 that is arranged between two neighboring clamp bars 65 is thus clamped against each other the influence of the compression force that results from compressing the first leaf spring element 79 and the second leaf spring element 81.

The rods 87, 89, 91 do not only serve as tie rods. By extending through the holes 77 of the clamp bars 65, the rods 87, 89, 91 couple neighboring clamp bars 65 in each stack 61, 63 or clamp bars, such that relative movement between neighboring clamp bars 65 in each stack 61, 63 or clamp bars in a perpendicular direction to the direction of stacking is prevented.

As shown in figure 4, each battery cell 47 is arranged between two separation sheets 53. The separation sheets 53 are at the end 53 a that is near the positive tab 49 and negative tab 51 of the battery cell 47 coupled to the frame 37 on which the clamp bars 65 are arranged. In particular the separation sheets 53 that are arranged between two battery cells 47 are provided with tabs 97. Each tab 97 is provided with a hole 77 and extends in a slot 99 provided in a respective clamp bar 65 or in a slot 101 provided in the clamping face of a respective clamp bar 65, such that the hole 77 of the tab 97 aligns with the hole 77 in the clamp bar 65. One of the rods 87, 91 extends through the hole 77 of the tabs 97, such that the separation sheets 53 provided with the tabs 97 are coupled to the clamp bars 65 and to the frame 37 via the rods 87, 91. Each pair of separation sheets 53 on opposite sides of a battery cell 47 are coupled to each other at the end 53b opposite to the clamp bars 65 and are spaced apart by means of at least one spacer element 103 arranged between the separation sheets 53. The spacer element is arranged such that it supports the battery cell 47 along the edge 47c beyond the positive tab 49 and negative tab 51. In the embodiment shown in figure 4 all separation sheets 53 and spacer elements 103 have holes 105 arranged through which threaded rods 107, 109, and 111 extend. The threaded rods 107, 109, 111 couple the separation sheets 53 and the spacer elements 103. Nuts 113 are arranged on the ends of the threaded rods 107, 109, 111. As shown in figure 4, there are also spacer elements 115 arranged between the separation sheets 53 at the end 53a the separation sheets 53. Treaded rods 117, 119 are arranged through holes 121 in the separation sheets 53 and the spacer elements 115 for coupling the separation sheets 53 and the spacer elements 115. Nuts 125 are arranged on the ends of the threaded rods 117, 119.

Figures 5 to 13, steps of an embodiment of the method for assembling the battery cell stack 21 are shown.

Figure 5 shows the first flanged frame element 39 having mounted thereon the three rods 87, 89, and 91, which extend perpendicular to the first flanged frame element 39 and parallel to each other. As shown after mounting the three rods 87, 89, and 91, the first leaf spring element 79 is slid over three rods 87, 89, and 91.

Figure 6 shows that the first end bar 67 is slid over three rods 87, 89, and 91. As shown the first end bar 67 has a recess in its clamping face 73 in which recess one end 75a of the conductive element 75 is arranged.

Figure 7 shows that the first separation sheet 53 is arranged adjacent the first end bar 67.

Figure 8 shows that the first battery cell 47 is arranged on the first separation sheet 53 with its front face (not shown) contacting the separation sheet 53 and its rear face 47b facing away from the separation sheet 53. The positive tab 49 and negative tab 51 of the first battery cell 47 are arranged on the first end bar 67, such that the contact faces of the tabs 49, 51 are contact with the clamping face 73 of the end bar 67. The contact face of the positive tab 49 is thus in contact with the conductive element 75. The first end bar 67 is made of an electrically insulating material such that arranging the positive tab 49 and negative tab 51 or the first battery cell 47 on the first end bar 67 does not result in short circuiting the first battery cell 47.

Figure 9 shows that subsequently, a second separation sheet 153 is arranged on the rear face 47a of the first battery 47, in the tabs 197 of the separation sheet 153 are slid over the rods 87 and 91. Furthermore, spacer elements 103, 115 are arranged between the separation sheets 53, 153.

Figure 10 shows that the first clamp bar 65 or the first stack 61 or clamp bars, is slid over the rods 87 and 89. The first clamp bar 65 has arranged thereon the positive terminal 29. The part 29a of the positive terminal 29 arranged in the recess of the first clamp bar 65 is faced toward the contact face of the positive tab 49, such that the positive terminal 29 is brought in electrical contact with the positive tab 49. As shown both ends of the first clamp bar 65 have a rebated edge part. The rebated edge parts have arranged therein the holes 77, such that the rods 87, 89 extend through the rebated edge parts. The rebated edge part 125 through which the rod 87 extends embodied the slot 101 for a tab 97 of the next separation sheet 53. The rebated edge part 127 through which the rod extends 89 is complementary to a rebated edge part of the first clamp bar 65 or the second stack 63 or clamp bars 65, as will be explained under reference to figure 13.

Figure 11 shows that a temperature sensor 129 is arranged on the rear face 47b or the first battery 47 that is accessible through an opening 131 in the separation sheet 53.

Figure 12 shows that a second battery 147 is arranged on the second separation sheet 153 with its rear face (not shown) contacting the second separation sheet 153 and the temperature sensor 129, and with its front face 147a facing away from the separation sheet 153. The negative tab 151 or the second battery 147 is arranged on the first clamp bar 65, such that the contact face of the negative tab 151 is in contact with the clamping face 173 or the first clamp bar 65.

The positive tab 149 or the second battery cell 147 is arranged above the negative tab 51 or the first battery 47, such that the contact faces of the negative tab 51 and positive tab 149 are facing each other.

Figure 13 shows that subsequently, the tabs 197 of a third separation sheet 253, and the first clamp bar 165 of the second stack 63 or clamp bars are slid over the rods 87, 89 and 91. Before sliding the third separation sheet 253 and the first clamp bar 165 of the second stack 63 of clamp bars over the rods 87, 89 and 91, one tab 197 of the third separation sheet 253 is arranged in the slot 99 in the clamp bar 165, such that the hole in the tab 197 aligns with the hole 77 in the clamp bar 165. The third separation sheet 253 is arranged on the front face 47a of the first battery 47. Furthermore, spacer elements 103, 115 are arranged between the separation sheets 53, 153. The first clamp bar 165 of the second stack 63 of clamp bars has arranged in a recess of its clamping face that faces the positive tab 49 of the second battery 47, one end of the conductive element 175. As shown in the detail of figure 13, after sliding the first clamp bar 165 or the second stack 63 or clamp bars over the rods 89 and 91, the contact faces of the negative tab 51 of the first battery 47 and of the positive tab 49 of the second battery 147 are brought in direct contact, providing an electrical connection between the first battery 47 and the second battery 147. As shown in figure 13, the first clamp bar 165 or the second stack 63 or clamp bars is provided with four rebated edge parts, two at each end thereof. The first rebated edge part 135 through which the rod extends 89 is complementary to and in contact with the rebated edge part 127 or the first clamp bar 65 or the first stack 61 or clamp bars. The clamp bars 65, 165 are made of an electrically insulating material such that allowing the first clamp bar 65 or the first stack 61 or clamp bars and the first clamp bar 165 or the second stack 63 or clamp bars does not result in short circuiting second battery cell 147.

The second rebated edge part 137 through which the rod 89 extends is complementary to a rebated edge part of the second clamp bar or the first stack 61 or clamp bars that is slit over the rods 87 and 89 in a later step during assembly of the battery cell stack 21. The third rebated edge part 139 through which the rod 91 extends embodies a slot 101 in which the tab 97 or the second separation sheet 53 extends. The fourth rebated edge part 141 through which the rod 91 extends embodies a slot 101 in which the tab of a fourth separation sheet will extend in a later step during assembly of the battery cell stack 21.

As shown in figure 13, the clamp bar 65 or the first stack 61 or clamp bars and the clamp bar 165 or the second stack 63 or clamp bars are offset in the stacking direction, in particular offset by half the height of one clamp bar 165 measured in the stacking direction.

For further assembling the battery cell stack 21 the steps as explained under reference to figures 8 to 13 are repeated for each two subsequent battery cells, following in the steps as explained under reference to figures 9 and 10 in stead of a clamp bar having arranged thereon a positive terminal, a clamp bar is slid over rods 87 and 89 that is a mirror image of clamp bar 165 that is shown in figure 13. When the last battery cell of the stack 59 of battery cells is arranged on the stack, the positive tab of the last battery cell is brought into contact with the negative tab of the one but last battery cell by sliding a last clamp bar or the second stack 63 or clamp bars that correspond to clamp bar 165 or figure 13 over the rods 89 and 91 Subsequently, the last clamp bar or the first stack 61 or clamp bars is slid over the rods 87 and 89. The last clamp bar or the first stack 61 or clamp bars has been arranged in a recess after the negative terminal 31, such that the part of the negative terminal 31 arranged in the recess is brought into contact with the contact face of the negative tab of the last battery cell 47. Subtely, the second end bar 71 and the second leaf spring element 81 are slid over the rods 87, 89, and 91 , after which the second flanged frame element 41 is coupled to the ends of the rods 87, 89, and 91, by means of bolts that are screwed into threaded axial holes 143 of the rods 87, 89, 91. Sub much, the bolds are tightened pull pulling the flanged frame elements 39, 41 towards each other and compressing the leaf spring elements 79, 81, such that the positive tabs and negative tabs of the battery cells that are arranged in contact with each other between two clamp bars of either the first stack 61 or clamp bars and the second stack 63 or clamp bars are clamped against each other under influence of the compression force that results from compressing the leaf spring elements 79 and 81.

The first end bar 67, the second end bar 71, and the clamp bars 65 are all made of an electrically insulating material.

In stead of two stacks or clamp bars the clamp bars or the first stack and the clamp bars or the second stack are arranged end-to-end, a single stack on clamp bars may be used the clamp bars or the first stack and the clamp bars or the second stack are replaced with clamp bars that extend along the whole upper edge of the battery cells 47 on which the tabs are arranged.

Although the principles of the invention have been set forth above with reference to specific, it must be understood that this description is given solely by way of example and not as limitation to the scope of protection, which is defined by the appended claims.

Claims (24)

Conclusions A battery cell stack comprising: - a stack of battery cells, wherein each battery cell comprises a positive lip and a negative lip; - at least one stack of clamping bars arranged adjacent to the stack of battery cells; - a clamping mechanism which acts on the at least one stack of clamping bars at opposite ends of the at least one stack of clamping bars for clamping the clamping bars together; at which - for each pair of neighboring battery cells, the positive lip of one of the pair of battery cells and the negative lip of the other of the pair of battery cells are clamped together between a pair of neighboring clamp bars. The battery cell stack of claim 1, wherein - the clamped parts of the lips extend in parallel planes; and - the clamping mechanism is configured to exert a clamping force on the stack of clamping beams perpendicular to the planes. The battery cell stack of claim 1 or 2, wherein the clamping mechanism comprises: - at least one spring member arranged at at least one end of the at least one stack of clamping bars. The battery cell stack of claim 3, wherein the at least one spring member comprises a leaf spring member. The battery cell stack according to any of claims 1 or 4, wherein each two clamping bars that have a positive lip and a negative lip clamped between them are mutually coupled in a direction perpendicular to the at least one stack of clamping bars by means of at least one coupling device. The battery cell stack of claim 5, wherein the at least one coupling device comprises at least one bar extending through the stacked clamping bars. The battery cell stack of claim 6, wherein the at least one coupling device comprises: - at least two bars arranged in parallel and extending through the stacked clamping bars. A battery cell stack according to claim 6 or 7, wherein the at least one rod extending through the stacked clamp bars extends between opposite ends of the at least stack of clamp bars and is connected at the opposite ends of the at least stack of clamp bars. frame on which the clamping bars have been arranged. The battery cell stack of claim 8, wherein - at least two bars arranged in parallel extend through the stacked clamp bars between the opposite ends of the at least one stack of clamp bars and are each connected to the frame at the opposite ends of the stack of clamp bars. The battery cell stack according to any of claims 1 to 9, comprising: - a first stack of clamping bars and a second stack of clamping bars, wherein of each battery cell one of the positive lip and the negative lip is clamped between two adjacent clamping bars of the first stack of clamping bars and the other of the positive lip and the negative lip between two neighboring clamping bars of the second stack of clamping bars is clamped. The battery cell stack of claim 10 or 11, wherein - the first stack of clamping bars and the second stack of clamping bars extend in the same plane. 12, Battery cell stack according to claim 10 or 11, wherein - the clamping beams of the first stack of clamping beams and the clamping beams of the second stack of clamping beams are offset relative to each other in the stacking direction, preferably shifted by half the height of one clamping beam measured in the stacking direction. The battery cell stack of any one of claims 10 to 12, wherein - the clamping beams of the first stack of clamping beams and the clamping beams of the second stack of clamping beams are arranged end to end. The battery cell stack of claim 13, wherein - the clamping bars arranged end-to-end have complementary sunken edge areas at the meeting ends. The battery cell stack of claim 14 and any of claims 6 to 9, wherein - at least one bar extends through the complementary sunken edge areas of the stacked clamping bars. The battery cell stack of any one of claims 1 to 15, wherein - each battery cell is arranged between two separation plates, which separation plates at the end thereof that are located near the positive lip and the negative lip of the battery cell are coupled to a frame on which the clamping beams are arranged, and which plates are at the opposite end thereof coupled to at least one spacer member arranged between the plates, the at least one spacer member arranged so as to support the battery cell along its edge opposite the positive lip and the negative lip. The battery cell stack of claim 16, wherein - at each end thereof, each separator plate located near the positive lip and the negative lip of the battery cell extends into at least one slot arranged in at least one clamp bar and is coupled to the at least one clamp bar via a rod extending into the slot and extends through a hole in the separator plate. The battery cell stack of claim 17, wherein the rod: - extends between opposite ends of the at least one stack of clamping bars; - extends through the stacked clamping bars and through the hole in each of the partition plates; and - is connected at the opposite ends of the at least one stack of clamping beams to the frame on which the clamping beams are arranged. The battery cell stack of any one of claims 1 to 18, wherein - at least one of the opposite color planes of adjacent clamping bars between which the positive lip and negative lip of neighboring battery cells are clamped, is provided with a conductive element which is at one end thereof in conductive contact with one of the positive lip and negative lip and on the other end thereof is configured as an electrical connector. The battery cell stack of any one of claims 1 to 18, wherein - the battery cells are flat and rectangular and have the positive lip and the negative lip along at least one edge thereof. 21. Battery comprising: - a battery cell stack according to any one of claims 1 to 20; and - a holder with a closed bottom and an open top; and - a lid for closing the open top of the container; at which - the at least one stack of clamping bars and the clamping mechanism are arranged near the open top of the container and the ends of the battery cells opposite the positive and negative lips extend towards the bottom of the container. The battery of claim 21, wherein - the at least one stack of clamping bars and the clamping mechanism are arranged on a frame; - the battery cell stack is coupled to the holder near its open top via the frame; - the battery cell stack is coupled to the container near the underside thereof by means of a layer of cured resin in which the ends of the battery cells are immersed opposite the positive and negative lips. A method for assembling a battery cell stack comprising the steps of: - making a stack of battery cells wherein each battery cell comprises a positive lip and a negative lip; - arranging at least one stack of terminal blocks next to the stack of battery cells, arranging, for each pair of neighboring battery cells, the positive lip of one of the pair of battery cells and the negative lip of the other of the pair of battery cells between two adjacent clamp bars; - applying a clamping force to the at least one stack of clamping bars at opposite ends of the at least one stack of clamping bars for clamping the clamping bars together, the positive lips and the negative lips arranged between adjacent clamping bars being clamped against each other . A method for assembling a battery cell stack according to claim 23, wherein - during the making of a stack of battery cells at least one stack of clamping beams is arranged next to the stack of battery cells, wherein each time after stacking a next battery cell on a previous battery cell, the positive lip of one of the previous battery cell and the next battery cell and the negative lip of the other of the previous battery cell and the next battery cell on top of each other are arranged on a previous clamp bar of the at least one stack of clamp bars, and a next clamp bar is arranged above on the positive lip and the negative lip so that the positive lip and the negative lip between the previous clamp bar and the next clamp bar 10 are arranged. 1/9 2/9 3a 3/9 21b 1/9