WO2023228030A1

WO2023228030A1 - Busbar assembly for joining battery cells

Info

Publication number: WO2023228030A1
Application number: PCT/IB2023/055177
Authority: WO
Inventors: Ronald C HODGE
Original assignee: Molex, Llc
Priority date: 2022-05-25
Filing date: 2023-05-19
Publication date: 2023-11-30

Abstract

A busbar assembly for joining positive and negative leads of battery cells is provided. The busbar assembly includes an insulative housing, a conductive busbar attached to the housing, first and second jaws movably mounted within cavity spaces in the housing on opposite sides of the busbar, a first biasing member between the first jaw and the housing and a second biasing member between the second jaw and the housing. The first biasing member is compressible to allow insertion of the positive lead of the first battery cell between the busbar and the first jaw, and the second biasing member is compressible to allow insertion of the negative lead of the second battery cell between the busbar and the second jaw.

Description

BUSBAR ASSEMBLY FOR JOINING BATTERY CELLS

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to United States provisional Application No. 63/345,554, filed on May 25, 2022, the contents of which are incorporated herein in its entirety. FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to a busbar assembly for joining electrode leads of battery cells.

BACKGROUND

[0003] Prior art electrical attachment of adjacent battery cells in electric vehicle (EV) modules or packs use permanent methods like welding for a reliable connection. This inhibits second life usage of the individual battery cells, and maintenance replacement of individual battery cells in a module or pack.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The organization and manner of the structure and operation of the disclosed embodiments, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, which are notnecessarily drawn to scale, wherein like reference numerals identify like elements in which:

[0005] FIG. 1 depicts a perspective view of a busbar assembly and battery cells showing the busbar assembly in a locked position;

[0006] FIG. 2 depicts a perspective view of the busbar assembly with a portion of the housing removed to show internal components;

[0007] FIG. 3 depicts a front plan view of the busbar assembly with a portion of the housing removed to show internal components;

[0008] FIG. 4 depicts a front plan view of a housing of the busbar assembly;

[0009] FIG. 5 depicts a cross-sectional view of the busbar assembly;

[0010] FIG. 6 depicts a partial perspective view of the busbar assembly and battery cells, shown in cross-section, and showing the busbar assembly in an unlocked position; and

[0011] FIG. 7 depicts a partial perspective view of the busbar assembly and battery cells, shown in cross-section, and showing the busbar assembly in the locked position of FIG. 1. DETAILED DESCRIPTION

[0012] While the disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that as illustrated and described herein. Therefore, unless otherwise noted, features disclosed herein may be combined to form additional combinations that were not otherwise shown for purposes of brevity. It will be further appreciated that in some embodiments, one or more elements illustrated by way of example in a drawing(s) may be eliminated and/or substituted with alternative elements within the scope of the disclosure.

[0013] Directional terms such as front, rear, horizontal, vertical and the like are used for ease in explanation, and do not denote a required orientation in use.

[0014] A busbar assembly 20 electrically connects conductive pouch tabs or electrode leads 22, 24 of a pair of battery cells 26, 28. Each battery cell 26, 28 includes a positive electrode lead 22 and a negative electrode lead 24. The leads 22, 24 are formed of a flexible conductive material, and the leads 22, 24 are straight prior to assembly with the busbar assembly 20. The positive electrode lead 22 of one battery cell, for example battery cell 26, and the negative electrode lead 24 of the other battery cell, for example battery cell 28, are inserted directly into the busbar assembly 20, and the electrical connection of the leads 22, 24 are completed using the busbar assembly 20.

[0015] The busbar assembly 20 include a housing 30, a conductive conductor or busbar 32, first and second jaws 34, 36, and first and second biasing members 38, 40.

[0016] The housing 30 is insulative and includes a planar cover or front wall 42, planar top, bottom and side walls 44, 46, 48, 50 depending therefrom, a first rear wall portion 52 extending from rear ends of the walls 42, 44, 46, 48, and a second rear wall portion 54 extending from rear ends of the walls 42, 44, 46, 50. A lead receiving opening 56, see FIG. 5, is provided between the rear wall portions 52, 54 which opens into a cavity 58 formed by the walls 42, 44, 46, 48, 50, 52, 54. The housing 30 may be formed of plastic. Each rear wall portion 52, 54 has a first section 60 which is perpendicular to the respective side wall 46, 48, a second section 62 extending from an end of the first section 60 at an angle, and a third section 64 extending from an end of the second section 62 and which is perpendicular to the first section 60 and parallel to the side walls 46, 48. The second portions 62 form an included angle of ninety (90) degrees, such that each second section 62 is angled at forty -five (45) degrees from the first section 60. The third portions 64 are parallel to each other.

[0017] The busbar 32 is formed as a plate having opposite planar side surfaces 66, 68, and top, bottom and front and rear surfaces. The busbar 32 is fixedly mounted to the front wall 42 of the housing 30 and extends into the cavity 58 between the top and bottom walls 44, 46 to divide the cavity 58 into a first cavity space 58a and a second cavity space 58b, see FIG. 5, and further extends though the lead receiving opening 56 between the rear wall portions 52, 54. An end 70 of the busbar 32 may align with the first portions 60 of the rear wall portions 52, 54. The busbar 32 may extend along the entire front wall 42, or may extend along a portion of the front wall 42. As shown, the busbar 32 has a pair of tabs 72 that extend from a front end of the busbar 32 and seat within the openings 74 through the front wall 42 of the housing 30. Other structures for fixedly attaching the busbar 32 to the front wall 42 are within the scope of the present disclosure. The busbar 32 may be made of a conductive material such as copper, silver, and tin-plated copper with electrical conductivity, which allows for safe passage of high capacity currents.

[0018] The front wall 42 has a first pin receiving slot 76 therethrough which is in communication with the first cavity space 58a, and a second pin receiving slot 78 therethrough which is in communication with the second cavity space 58b. The first pin receiving slot 76 is on one side of the busbar 32 and the second pin receiving slot 78 is on the other side of the busbar 32. Each pin receiving slot 76, 78 is generally L-shaped having an outer vertical portion 80 which is parallel to the side walls 46, 48 of the housing 30, and an inner elongated horizontal portion 82 which parallel to the top and bottom walls 44, 46 of the housing 30. The horizontal portions 82 are aligned.

[0019] The first jaw 34 is mounted within the first cavity space 58a, and the second jaw 36 is mounted within the second cavity space 58b. Each jaw 34, 36 may be formed as an elongated bar, such as rectangular prism or a cube, having a surface 84 that is parallel to the planar side surfaces 66, 68 of the busbar 32. The surface 84 of the jaw 34 faces the surface 66 of the busbar 32, and the surface 84 of the jaw 36 faces the surface 68 of the busbar 32. The surface 84 of each jaw 34, 36 may have a plurality of teeth thereon, or may be planar. Each jaw 34, 36 has a height which is less than the front wall 42. Each jaw 34, 36 has a pin 86, 88 extending from a front surface thereof which may be cylindrical. The pin 86 of the jaw 34 seats within the pin receiving slot 76 and the pin 88 of the jaw 36 seats within the pin receiving slot 78. Each jaw 34, 36 may be formed of an insulative material or a conductive material.

[0020] The biasing members 38, 40 may be springs, and may be generally C-shaped springs, having a central curved section and opposite ends as shown in FIG. 3. Each biasing member 38, 40 may be formed of an insulative material or a conductive material. The biasing members 38, 40 may be leaf springs. The biasing members 38, 40 may be elastomeric blocks. Other biasing members are within the scope of the present disclosure. The first biasing member 38 is positioned within the first cavity space 58a between the first jaw 34 and the side wall 46, and the second biasing member 40 is positioned within the second cavity space 58b between the second jaw 36 and the side wall 48. If formed as generally C-shaped springs, the ends of the biasing members 38, 40 abut against the respective side walls 48, 50 and the top and bottom walls 44, 46, and the curved sections abut against the respective jaw 34, 36. When the pins 86, 88 are in the outer vertical portions 80 of the pin receiving slots 76, 78, the biasing members 38, 40 are compressed, and enlarged spaces 90a, 90b are formed between the jaws 34, 36 and the busbar 32. This provides an open position for the jaws 34, 36. When the pins 86, 88 are in the inner horizontal portions 82 of the pin receiving slots 76, 78, the biasing members 38, 40 are expanded, and the spaces 90a, 90b are reduced between the jaws 34, 36 and the busbar 32. This provides a closed position for the jaws 34, 36.

[0021] In use, the pins 86, 88 are initially positioned in the outer vertical portions 80 of the pin receiving slots 76, 78. The housing 30 is placed over the leads 22, 24 of the battery cells 26, 28 such that the lead 22 aligns with the second section 62 of the first rear wall portion 52, and the lead 24 aligns with the second section 62 of the second rear wall portion 54. As the busbar assembly 20 is pushed toward the battery cells 26, 28, the leads 22, 24 engage the second portions 62 of the rear wall portions 52, 54 and travel along the respective second portions 62, thereby starting a deformation of the leads 22, 24. As the busbar assembly 20 is pushed further toward the battery cells 26, 28, the leads 22, 24 engage the respective surfaces 66, 68 of the busbar 32 and deform between the busbar 32 and the third portions 64 of the rear wall portions 52, 54. As the busbar assembly 20 is pushed even further toward the battery cells 26, 28, the leads 22, 24 move into the spaces 90a, 90b between the busbar 32 and the respective jaws 34, 36. Once the first portions 60 of the rear wall portions 52, 54 engage with front ends of the battery cells 26, 28, the housing 30 is no longer pushed toward the battery cells 26, 28.

[0022] Thereafter, the pins 86, 88 are moved from their positions in the outer vertical portions 80 of the pin receiving slots 76, 78 and into the inner horizontal portions 82 of the pin receiving slots 76, 78. This allows for expansion of the biasing members 38, 40 and moves the jaws 34, 36 through the spaces 90a, 90b into contact with the leads 22, 24 to clamp the leads 22, 24 and the busbar 32 together and complete the electrical connection. The lengths of the inner horizontal portions 82 of the pin receiving slots 76, 78 allow for varying widths of leads 22, 24 to be inserted into the busbar assembly 20. [0023] The busbar assembly 20 can be removed from the battery cells 26, 28 for reuse or replacement. To do so, the pins 86, 88 are moved from their positions in the inner horizontal portions 82 of the pin receiving slots 76, 78 and into the outer vertical portions 80 of the pin receiving slots 76, 78 to relieve the clamping pressure provided by the biasing members 38, 40 on the jaws 34, 36 and to open the spaces 90a, 90b between the jaws 34, 36 and the busbar 32. Thereafter, the busbar assembly 20 can be pulled off of the leads 22, 24.

[0024] The movement of the pins 86, 88 within the pin receiving slots 76, 78 can be effected by using a tool.

[0025] The biasing members 38, 40, pin receiving slots 76, 78 and pins 86, 88 described and shown herein form one example of a lock that can be provided to hold the first and second jaws 34, 36 in the open position and in the closed position. Other locks are within the scope of the disclosure. For example, threaded fasteners can be provided through the side walls 46, 48 and have ends that engage with the first and second jaws 34, 36 to move the jaws 34, 36 into the open and closed positions.

[0026] The rear wall portions 52, 54 can be formed in different shapes, provided the walls forming the rear wall portions 52, 54 funnel the flexible leads 22, 24 into position between the busbar 32 and the first and second jaws 34, 36.

[0027] The tabs 72 on the busbar 32 can be connected to a connector, a header, a PCB or other means, for voltage and thermistor measurements.

[0028] While the pin receiving slots 76, 78 are shown and described as being through the front wall 42 of the housing 30 and the pins 86, 88 on the front end of the jaws 34, 36, the pin receiving slots 76, 78 can be provided through the top or bottom walls 44, 46 of the housing 30 with the pins 86, 88 on the top or bottom ends of the jaws 34, 36.

[0029] While a particular embodiment is illustrated in and described with respect to the drawings, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the appended claims. It will therefore be appreciated that the scope of the disclosure and the appended claims is not limited to the specific embodiments illustrated in and discussed with respect to the drawings and that modifications and other embodiments are intended to be included within the scope of the disclosure and appended drawings. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the disclosure and the appended claims. Further, the foregoing descriptions describe methods that recite the performance of a number of steps. Unless stated to the contrary, one or more steps within a method may not be required, one or more steps may be performed in a different order than as described, and one or more steps may be formed substantially contemporaneously. Finally, the drawings are not necessarily drawn to scale.

Claims

We claim:

1. A busbar assembly for joining a positive lead of a fust battery cell to a negative lead of a second battery cell, the busbar assembly comprising: an insulative housing defining a cavity; a conductive busbar within the cavity and attached to the housing; a first jaw movably mounted in the cavity on a first side of the busbar; a first lock between the housing and the first jaw, wherein the first lock is configured to be engaged to hold the first jaw in a position spaced from the busbar to allow insertion of the positive lead of the first battery cell between the busbar and the first jaw and is further configured to be released to allow the first jaw to move to engage the positive lead of the first battery cell with the busbar; a second jaw movably mounted in the cavity on a second opposite side of the busbar; and a second lock between the housing and the second jaw, wherein the second lock is configured to be engaged to hold the second jaw in a position spaced from the busbar to allow insertion of the negative lead of the second battery cell between the busbar and the second jaw and is further configured to be released to allow the second jaw to move to engage the negative lead of the second battery cell with the busbar.

2. The busbar assembly of claim 1, wherein each lock includes a biasing member.

3. The busbar assembly of claim 1, wherein the housing has a lead receiving opening therethrough in communication with the cavity to allow insertion of the leads, the lead receiving opening having first and second angled walls, the first wall being on the first side of the busbar and the second wall being on the second side of the busbar.

4. The busbar assembly of claim 1, wherein the first lock includes a first biasing member between the first jaw and the housing, wherein the first biasing member is compressible to allow insertion of the positive lead of the first battery cell between the busbar and the first jaw; and wherein the second lock includes a second biasing member between the second jaw and the housing, wherein the second biasing member is compressible to allow insertion of the negative lead of the second battery cell between the busbar and the second jaw.

5. The busbar assembly of claim 4, wherein the housing has first and second spaced apart pin receiving slots therethrough, the first pin receiving slot being on the first side of the busbar and the second pin receiving slot being on the second side of the busbar, each pin receiving slot having an elongated first section and a second section which is angled relative to the first section; and wherein each jaw has a pin extending therefrom, the pin of the first jaw being seated within the first pin receiving slot and movable relative thereto when the first jaw moves, and the pin of the second jaw being seated within the second pin receiving slot and movable relative thereto when the second jaw moves, wherein the first biasing member is held in a compressed condition when the first pin is in the second section of the fust pin receiving slot and the second biasing member is held in a compressed condition when the second pin is in the second section of the second pin receiving slot.

6. The busbar assembly of claim 5, wherein the pin receiving slots are in a front wall of the housing.

7. The busbar assembly of claim 5, wherein the housing has a lead receiving opening therethrough in communication with the cavity to allow insertion of the leads, the lead receiving opening having first and second angled walls, the first wall being on the first side of the busbar and the second wall being on the second side of the busbar.

8. The busbar assembly of claim 7, wherein the pin receiving slots are in a front wall of the housing and the lead receiving opening is in a rear wall of the housing.

9. The busbar assembly of claim 1, wherein the busbar has at least one tab that extends through a wall of the housing.

10. The busbar assembly of claim 1, wherein each jaw has teeth thereon which face the busbar.

11. A busbar assembly for joining a positive lead of a fust battery cell to a negative lead of a second battery cell, the busbar assembly comprising: an insulative housing; a conductive busbar attached to the housing; a first jaw movably mounted within a first cavity space in the housing on a first side of the busbar; a first biasing member within the first cavity space and between the first jaw and the housing, wherein the first biasing member is compressible to allow insertion of the positive lead of the first battery cell between the busbar and the first jaw; a second jaw movably mounted within a second cavity space in the housing on a second opposite side of the busbar; and a second biasing member within the second cavity space and between the second jaw and the housing, wherein the second biasing member is compressible to allow insertion of the negative lead of the second battery cell between the busbar and the second jaw.

12. The busbar assembly of claim 11, wherein each biasing member is spring.

13. The busbar assembly of claim 12, wherein each spring is C-shaped.

14. The busbar assembly of claim 11 , wherein the housing has first and second spaced apart pin receiving slots therethrough, each pin receiving slot having an elongated first section and a second section which is angled relative to the fust section; and wherein each jaw has a pin extending therefrom, the pin of the first jaw being seated within the first pin receiving slot and movable relative thereto when the first jaw moves, and the pin of the second jaw being seated within the second pin receiving slot and movable relative thereto when the second jaw moves, wherein the first biasing member is held in a compressed condition when the first pin is in the second section of the fust pin receiving slot and the second biasing member is held in a compressed condition when the second pin is in the second section of the second pin receiving slot.

15. The busbar assembly of claim 14, wherein the housing has a lead receiving opening therethrough in communication with the cavity to allow insertion of the leads, the lead receiving opening having first and second angled walls, the first wall being on the first side of the busbar and the second wall being on the second side of the busbar.

16. The busbar assembly of claim 15, wherein the lead receiving opening is in a rear wall of the housing.

17. The busbar assembly of claim 16, wherein the pin receiving slots are in a front wall of the housing.

18. The busbar assembly of claim 11, wherein the housing has a lead receiving opening therethrough in communication with the cavity to allow insertion of the leads, the lead receiving opening having first and second angled walls, the first wall being on the first side of the busbar and the second wall being on the second side of the busbar.

19. The busbar assembly of claim 11, wherein the busbar has at least one tab that extends through a wall of the housing.

20. The busbar assembly of claim 11, wherein each jaw has teeth thereon which face the busbar.