Secondary Battery Module

Abstract

To provide a secondary battery module in which, when a pair of holders are fastened with a coupling member, the electric short-circuit of tabs with different polarities by the coupling member is prevented.SOLUTION: A secondary battery module includes a first holder that accommodates one side (lower side) of a plurality of battery cells apart from each other in a first direction and a second direction, which intersect with each other, a second holder that accommodates the other side (upper side) of the battery cells, a coupling member that is formed of a conductive material and fastens the first holder and the second holder to each other in a third direction that intersects with the second direction, a plurality of tabs electrically coupling the battery cells, and bus bars coupling the tabs to a battery management system (BMS). At least one of the first holder and the second holder includes a rib protruding in the third direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a secondary battery module, and more particularly to a secondary battery module in which a pair of holders are fastened together with a connecting member, and tabs that electrically connect a plurality of battery cells housed in the holders are connected to a battery management system with bus bars. [Background technology]

[0002] Unlike primary batteries, rechargeable batteries are batteries that can be repeatedly charged and discharged. Small-capacity secondary batteries are used in small, portable electronic devices such as mobile phones, laptops, and camcorders. Large-capacity and high-density secondary batteries are used as power sources for driving motors in hybrid and electric vehicles and for energy storage.

[0003] The secondary battery may be used as a secondary battery module including a plurality of battery cells connected in series and / or parallel to drive a motor of a hybrid vehicle, which requires a relatively high energy density. For example, to realize a relatively high-power secondary battery module (e.g., an electric vehicle), a secondary battery module is formed by connecting electrode terminals of a plurality of battery cells provided in a number corresponding to a desired amount of power.

[0004] For example, a secondary battery module includes a pair of holders, each housing a battery cell, and is fastened together with a fastening member to be housed in a case. Before fastening the pair of holders with the fastening member, the battery cells are connected with tabs. On one side of the holder, a tab carrying a negative electrode and a tab carrying a positive electrode are both present. On the other side of the holder, a tab carrying a negative electrode and a tab carrying a positive electrode are also present. Therefore, if the fastening member is accidentally dropped during fastening of the pair of holders, tabs of opposite polarities may be short-circuited by the fastening member. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of one embodiment of the present invention is to provide a secondary battery module that prevents electrical short-circuiting between tabs having different polarities due to a connecting member when a pair of holders are fastened together with the connecting member. [Means for solving the problem]

[0006] A secondary battery module according to one embodiment of the present invention includes a first holder that accommodates one side (lower side) of a plurality of battery cells spaced apart in a first direction and a second direction that intersect with each other, a second holder that accommodates the other side (upper side) of the battery cells, a connecting member made of a conductive material that fastens the first holder and the second holder to each other in a third direction that intersects with the second direction, a plurality of tabs that electrically connect the battery cells, and a bus bar that connects the tabs to a battery management system (BMS), and at least one of the first holder and the second holder has a rib protruding in the third direction.

[0007] The tabs may include first tab members that are bent and arranged on the upper and side surfaces of the second holder and that are bent and arranged on the lower and side surfaces of the first holder to connect the plurality of battery cells in parallel, and second tab members that are arranged on the upper surface of the second holder and the lower surface of the first holder to connect the plurality of battery cells in parallel and in series.

[0008] The first tab member may be provided in one piece and may have a positive or negative electrode, and the second tab member may be provided in two pieces, and the second tab member adjacent to the first tab member may have a different polarity from the first tab member, and two adjacent second tab members may have different polarities from each other.

[0009] The rib may be provided between the first tab member and the second tab member having mutually different polarities, and between two second tab members having mutually different polarities.

[0010] The rib may include a curved portion formed along a curved line along the shape of the receiving hole of the second holder that receives the battery cell, and a straight portion that connects the curved portion to each other in a straight line at the closest distance.

[0011] The rib may further include a mounting portion that provides a position for mounting the thermistor by removing a portion of the curved portion.

[0012] The connecting member may have a threaded portion formed on one end of the post to penetrate the second holder and connect to the first holder, and a head portion formed on the other end of the post having a diameter larger than the diameter of the post.

[0013] The rib has a height (H) protruding in the third direction, and the height (H) may be greater than half the size (D1-D2) obtained by subtracting the diameter (D2) of the pillar from the diameter (D1) of the head (H>(D1-D2) / 2).

[0014] The connecting member may be formed longer than the shortest distance between the first tab member and the second tab member adjacent in the second direction and the shortest distance between the second tab members.

[0015] The lower surface of the first holder and the upper surface of the second holder may have a receiving portion corresponding to the thickness of the tab to receive the tab.

[0016] The first holder may have an opening on a lower surface thereof that is deep enough to reach the electrode terminal of the battery cell, and the second holder may have an opening on an upper surface thereof that is deep enough to reach the electrode terminal of the battery cell, and the tab may have a connecting portion that is bent at one side of the receiving portion to the depth of the opening and is connected to the electrode terminal.

[0017] In addition, one embodiment of the present invention further includes a case that accommodates the first holder side (lower side) and a cover that covers the second holder side (upper side), and the cover may have corresponding ribs on its inner surface that face the battery cell.

[0018] The ribs may be formed in the shape of regular hexagons and may be repeatedly arranged in the first direction and the second direction. [Effects of the Invention]

[0019] In one embodiment, the secondary battery module has a rib on the first holder or the second holder. When fastening the first and second holders with a connecting member, if the connecting member falls due to an operational error, the rib lifts one end of the connecting member, preventing that end from coming into contact with the tab. This prevents electrical short-circuiting of tabs with opposite polarities caused by the connecting member. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view of a secondary battery module according to a first embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a secondary battery module according to a first embodiment of the present invention. [Figure 3] 3 is a partial cross-sectional perspective view taken along line III-III in FIG. 1, illustrating the relationship in which a first holder and a second holder are fastened together by a connecting member. [Figure 4] 1. FIG. 4 is a plan view showing the connection and arrangement of battery cells and tabs on the upper surface of a second holder of the secondary battery module of FIG. [Figure 5] 1. FIG. 4 is a plan view showing the connection and arrangement of battery cells and tabs on the bottom surface of a first holder of the secondary battery module of FIG. [Figure 6] 2 is a partially sectional perspective view showing a state in which tabs are coupled to the lower surface of the first holder and the upper surface of the second holder in FIG. 1.

[0023] FIG. [Figure 7] FIG. 10 is a perspective view of a secondary battery module (connected to a case as a core pack) according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view of a secondary battery module (in a state where the secondary battery module is combined with a cover as a core pack) according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a longitudinal cross-sectional view taken along line IX-IX in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, parts unnecessary for the explanation are omitted in order to clearly explain the present invention, and the same reference numerals are used throughout the specification to refer to the same or similar components.

[0022] Fig. 1 is a perspective view of a secondary battery module according to a first embodiment of the present invention, and Fig. 2 is an exploded perspective view of the secondary battery module according to the first embodiment of the present invention. Referring to Figs. 1 and 2, the secondary battery module 1 of the first embodiment includes a first holder 10, a second holder 20, a connecting member 60, a plurality of tabs 30 (31, 32), and a plurality of bus bars 40 (41, 42) (see Figs. 7 and 8).

[0023] For example, the first holder 10 may form a bottom holder of the secondary battery module 1, the second holder 20 may form a top holder, and the tab 30 may be formed of a nickel tab containing nickel material.

[0024] The first holder 10 and the second holder 20 form a honeycomb structure inside to accommodate a plurality of battery cells 50 spaced apart in a first direction (x-axis direction) and a second direction (y-axis direction) intersecting the first direction, and are connected to each other in a third direction (z-axis direction) intersecting the second direction.

[0025] 1, the first holder 10 accommodates the lower side of the battery cell 50, and the second holder 20 accommodates the upper side of the battery cell 50. In this state, the first and second holders 10 and 20 are fastened together by a connecting member 60.

[0026] Figure 3 is a partial cross-sectional perspective view showing the relationship of fastening the first holder and the second holder with a connecting member taken along line III-III in Figure 1. Referring to Figures 1 to 3, the first holder 10 and the second holder 20 can be connected by a snap fit structure between a protrusion 11 provided on the outside of the first holder 10 and a connecting portion 12 provided on the outside of the second holder 20 that corresponds to the protrusion 11.

[0027] For example, the coupling member 60 is formed as a pillar structure longer than the height of the second holder 20, and includes a threaded portion 601 and a head portion 62 at both ends of the pillar. The threaded portion 601 is formed as a screw at one end of the pillar so as to penetrate the second holder 20 and be screwed to the first holder 10. The head portion 62 is formed on the other side of the pillar with a diameter (D1) larger than the diameter (D2) of the pillar, and is located on the upper surface of the second holder 20. The head portion 62 has a driver groove. The coupling member 60 may be formed of a conductive material.

[0028] Fig. 4 is a plan view showing the connection and arrangement of battery cells and tabs on the top surface of the second holder of the secondary battery module of Fig. 1, and Fig. 5 is a plan view showing the connection and arrangement of battery cells and tabs on the bottom surface of the first holder of the secondary battery module of Fig. 1. Referring to Figs. 1, 4, and 5, in the secondary battery module 1, a plurality of tabs 30 connect battery cells 50 in a plurality of series and a plurality of parallel configurations.

[0029] For example, the plurality of tabs 30 include one first tab member 31 and a plurality of second tab members 32 (321, 322). The first tab member 31 is bent and arranged on the upper and side surfaces of the second holder 20, and is bent and arranged on the lower and side surfaces of the first holder 10 to connect the plurality of battery cells 50 in parallel.

[0030] The first tab member 31, which is a bent tab member, includes an inner flat portion 311 connected to the battery cell 50, and inner side surface portions 312 bent at the inner flat portion 311 and disposed on the sides of the first and second holders 10, 20.

[0031] The second tab members 32 (321, 322) are disposed on the upper surface of the second holder 20 and the lower surface of the first holder 10 to form a plurality of parallel connections and a plurality of series connections between the plurality of battery cells 50. The second tab members 32 (321, 322) may be formed as plate-shaped tab members that connect the battery cells 50 to each other.

[0032] That is, the first tab member 31 and the second tab member 32 (321, 322) electrically connect the battery cells 50 in parallel and series along the first direction (x-axis direction) and are spaced apart in the second direction (y-axis direction).

[0033] The first tab member 31 and the second tab member 32 (321, 322) are sequentially arranged on the upper surface of the second holder 20 along the second direction, and are sequentially arranged on the lower surface of the first holder 10 along the opposite direction to the second direction in a symmetrical structure, thereby electrically connecting the battery cells 50 in parallel and series.

[0034] For convenience, the structure of the tabs 30 on the upper surface of the second holder 20 and the structure of the tabs 30 on the lower surface of the first holder 10 will be described together. The first tab member 31 electrically connects some of the plurality of battery cells 50 in parallel along a first direction. The second tab members 32 (321, 322) electrically connect other some of the plurality of battery cells 50 in parallel along the first direction. The first and second tab members 31, 32 are arranged symmetrically on the upper surface of the second holder 20 and the lower surface of the first holder 10, thereby connecting the parallel connections in series.

[0035] For example, if one first tab member 31 is provided on the upper surface of the second holder 20 or the lower surface of the first holder 10 and has a positive or negative polarity, two second tab members 32 (321, 322) are provided and have a polarity different from that of the second tab member 321 adjacent to the first tab member 31, and the second tab members 321, 322 of the second tab members 32 also have polarities different from each other.

[0036] That is, when the first tab member 31 is a positive electrode, the second tab member 321 adjacent to the first tab member 31 is a negative electrode, and the other second tab member 322 is a positive electrode. Conversely, when the first tab member 31 is a negative electrode, the second tab member 321 adjacent to the first tab member 31 is a positive electrode, and the other second tab member 322 is a negative electrode.

[0037] Figure 6 is a partial cross-sectional perspective view showing the state in which the tabs are coupled to the lower surface of the first holder 10 and the upper surface of the second holder 20 in Figure 1. Referring to Figure 6, the lower surface of the first holder 10 and the upper surface of the second holder 20 are provided with receiving portions 21. The receiving portions 21 are formed to correspond to the thickness of the tabs 30 so as to receive the tabs 30.

[0038] The first holder 10 and the second holder 20 each have an opening 22 on their bottom and top surfaces, the opening having a depth D22 that reaches the electrode terminal 51 of the battery cell 50. The tab 30 has a connecting portion 33 that is bent to the depth D22 on one side of the receiving portion 21 and is connected to the electrode terminal 51.

[0039] As a result, the upper surface of the second holder 20 and the upper surface of the tab 30 form a plane having the same height. Therefore, even if the rib 61 is formed on the upper surface of the second holder 20, when attaching insulating tape (not shown) to the upper surfaces of the second holder 20 and the tab 30 after fastening the coupling member 60, the adhesiveness of the insulating tape can be improved.

[0040] 1, 2, and 4, at least one of the first holder 10 and the second holder 20 has a rib 61 protruding in the third direction. In the first embodiment, the rib 61 is provided on the second holder 20 located at the top in the module 1 state.

[0041] The ribs 61 are provided between the first tab member 31 and the second tab member 32, which have opposite polarities, and between the two second tab members 321, 322. One of the ribs 61 is disposed between the first tab member 31 and the second tab member 32, which have opposite polarities. The other rib 61 is disposed between the second tab member 321 and the second tab member 322, which have opposite polarities.

[0042] The rib 61 includes curved portions 611 and straight portions 612. The curved portions 611 are formed in a curve that follows the shape of the receiving holes of the second holder 20 that receive the cylindrical battery cells 50. The straight portions 612 connect adjacent curved portions 611 to each other in a straight line at the closest distance.

[0043] The rib 61 includes a mounting portion 613 formed by removing a part of the curved portion 612. The mounting portion 613 ensures that the position and space for mounting the thermistor 63 are secured despite the formation of the rib 61.

[0044] The thermistor 63 is installed on the upper rib 61 of the second holder 20 to sense the temperature of the tab 30 and the upper part of the second holder 20 and transmit the data to the battery management system (BMS). The rib 61 allows the thermistor 63 to be stably installed, stably sense the thermal signal and transmit it as an electrical signal.

[0045] The rib 61 has a height (H, see Figure 3) protruding in the third direction, and the height (H) is formed to be greater than half the size (D1-D2) obtained by subtracting the diameter (D2) of the pillar from the diameter (D1, see Figure 2) of the head 62 (H>(D1-D2) / 2).

[0046] 4 or when the threaded portion 601 comes into contact with the first tab member 31 on one side, the head 62 does not come into contact with the adjacent second tab member 32. This prevents the first and second tab members 31, 32 from being short-circuited by the connecting member 60.

[0047] In addition, even if the connecting member 60 falls onto the rib 61, or even if the threaded portion 601 comes into contact with one second tab member 321, the head 62 does not come into contact with the other adjacent second tab member 322. This prevents the connecting member 60 from short-circuiting the second tab members 32 (321, 322).

[0048] The connecting member 60 is formed to be longer than the shortest distance (L1) between the first tab member 31 and the second tab member 32 adjacent in the second direction (y-axis direction) and the shortest distance (L1) between the second tab members 32 (321, 322).

[0049] Even if the connecting member 60 is formed longer than these minimum distances (L1, L2), one side is lifted and separated from the tab 30 by the rib 61, so that the connecting member 60 can prevent the tab 30 from short-circuiting.

[0050] FIG. 7 is a perspective view of a secondary battery module (in a state where the secondary battery module is combined into a case as a core pack) according to a second embodiment of the present invention, and FIG. 8 is a perspective view of a secondary battery module (in a state where the secondary battery module is combined into a cover as a core pack) according to the second embodiment of the present invention.

[0051] 7 and 8, the secondary battery module 2 of the second embodiment is formed by incorporating two core packs 101 and 102 into a case 71 and covering it with a cover 72. The case 71 protects the core packs 101 and 102. Each of the core packs 101 and 102 can form multiple series connections and multiple parallel connections with multiple battery cells 50, and can also be formed with the secondary battery module 1 of the first embodiment.

[0052] When the core packs 101 and 102 form multiple series connections and multiple parallel connections to the battery cells 50, the secondary battery module 2 requires high durability against external impacts since the voltage and current are high during use.

[0053] 9 is a longitudinal cross-sectional view taken along line IX-IX in FIG. 8. In the secondary battery module 2, a case 71 houses the first holder 10, and a cover 72 covers the second holder 20. The cover 72 has ribs 721 on its inner surface that face the battery cells 50. The ribs 721 are formed as regular hexagons on the xy plane with a height in the third direction and are repeatedly arranged in the first and second directions.

[0054] The ribs 721 increase the strength of the cover 72, thereby achieving high durability against external impacts. In addition, in the event of a fire, such as a runaway battery cell 50, the ribs 721 facilitate gas discharge through the space formed between the inner surface of the cover 72 and the second holder 20, thereby preventing the spread of fire to other adjacent battery cells 50.

[0055] 7 and 8, the busbars 40 (41, 42) connect the tabs 30 to a battery management system (BMS). As an example, the busbars 40 include a first busbar member 41 and a second busbar member 42. The core packs 101, 102 each include the first and second busbar members 41, 42.

[0056] In the case of adjacent core packs 101, 102, the first bus bar member 41 used in one core pack 101, 102 is connected on one side to the first tab member 31, which is a bent tab member, on the upper surface of the second holder 20, and is connected on the other side to the battery management system (BMS). The second bus bar member 42 is connected on one side to the second tab member 322, which is a plate-shaped tab member, on the upper surface of the second holder 20, and is connected on the other side to the battery management system (BMS).

[0057] Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made within the scope of the claims, the description of the invention, and the accompanying drawings, and it is natural that these also fall within the scope of the present invention. [Explanation of symbols]

[0058] 2: Secondary battery module 10: First holder 11: Protruding part 12: Connecting member 20: Second Holder 21: Storage unit 22:Aperture 30: Tab 31: First tab member 32, 321, 322: second tab members 33:Connection part 40: Busbar 41: First bus bar member 42: Second bus bar member 50: Battery cell 60: Connecting member 61: Rib 62:Head 71: Case 72: Cover 101, 102: Core Pack 311: Inner plane part 312:Inner side part 601: Threaded part 611: Curved part 612: Straight section 613: Installation part 721: Rib BMS: Battery Management System D22: Depth H: Height L1: Minimum separation distance

Claims

1. a first holder for receiving one side of a plurality of battery cells spaced apart in a first direction and a second direction perpendicular to each other; a second holder for receiving the other side of the battery cell; a connecting member formed of a conductive material and fastening the first holder and the second holder to each other in the first direction and a third direction perpendicular to the second direction; a plurality of tabs electrically connecting the battery cells; and a bus bar connecting the tab to a battery management system (BMS); At least one of the first holder and the second holder includes a rib protruding in the third direction. The tab a first tab member that is bent and disposed on an upper surface and a side surface of the second holder and that is bent and disposed on a lower surface and a side surface of the first holder, and that connects a plurality of battery cells in parallel; a second tab member disposed on an upper surface of the second holder and a lower surface of the first holder, the second tab member connecting the plurality of battery cells in parallel and in series; The first tab member is provided one by one and carries a positive electrode or a negative electrode, The second tab members are provided in two numbers, Of the two, the second tab member adjacent to the first tab member has a polarity different from that of the first tab member, two adjacent second tab members have different polarities; The rib is A secondary battery module is provided between the first tab member and the second tab member having polarities different from each other, and between two second tab members having polarities different from each other.

2. The rib is a curved portion formed along a curved line along the shape of the receiving hole of the second holder that receives the battery cell; and The secondary battery module of claim 1 , further comprising a straight portion connecting the curved portions to each other at a closest distance.

3. The rib is The secondary battery module of claim 2 , further comprising a mounting portion provided by removing a portion of the curved portion to provide a position for mounting a thermistor.

4. The coupling member is a threaded portion formed on one end of the post to penetrate the second holder and be coupled to the first holder; and The secondary battery module according to claim 1 , wherein a head portion having a diameter larger than that of the pillar is formed on the other side of the pillar.

5. The rib is having a height (H) protruding in the third direction, The height (H) is 5. The secondary battery module of claim 4, wherein H is greater than half the diameter (D1-D2) of the head minus the diameter (D2) of the pillar (H>(D1-D2) / 2).

6. The coupling member is The secondary battery module of claim 1 , wherein the distance between the first tab member and the second tab member adjacent in the second direction is longer than the shortest distance between the first tab member and the second tab member adjacent in the second direction and the shortest distance between the second tab members.

7. The lower surface of the first holder and the upper surface of the second holder are The secondary battery module according to claim 1 , further comprising a receiving portion corresponding to a thickness of the tab for receiving the tab.

8. the first holder has an opening formed on its bottom surface that is deep enough to reach the electrode terminals of the battery cells; the second holder has an opening formed on its upper surface, the opening having a depth reaching the electrode terminal of the battery cell; The tab The secondary battery module of claim 7 , further comprising a connecting portion bent at one side of the receiving portion by the depth of the opening and connected to the electrode terminal.

9. a case for accommodating the first holder; and a cover for covering the second holder side; The cover is The secondary battery module according to claim 1 , further comprising corresponding ribs on an inner surface facing the battery cells.

10. A secondary battery module as described in Claim 9, wherein the ribs of the cover are formed as regular hexagons and are repeatedly arranged in the first direction and the second direction.

Images