Secondary battery module, secondary battery pack, and method for assembling secondary battery module

Abstract

This invention relates to the field of battery technology, and provides a secondary battery module, a secondary battery pack, and an assembly method for the secondary battery module. The secondary battery module includes a plurality of batteries connected in series along the same direction and a first tube accommodating the plurality of batteries. The first tube has an inwardly recessed annular groove at the junction of adjacent batteries, the depth of which is greater than the distance between the first tube and the battery. In this invention's secondary battery module, the annular groove at the junction of the first tube and adjacent batteries acts as a limiting component, providing a tightening and fixing function, thereby preventing the battery from moving within the first tube. Furthermore, since the annular groove will be provided later, the gap between the first tube and the battery can be set to be wider before battery installation to facilitate battery installation.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a secondary battery module, a secondary battery pack, and a method for assembling the secondary battery module. Background Technology

[0002] As the new energy crisis intensifies, traditional gasoline-powered vehicles are gradually being replaced by new energy vehicles, with hybrid or pure electric vehicles, as a type of new energy vehicle, experiencing particularly rapid development. With the increasing maturity and development of electric vehicle secondary battery pack technology, electric vehicles are destined to become the main trend in the future automotive industry. However, current electric vehicle secondary battery packs also present some problems in use, such as poor thermal management and a non-compact structure of the internal secondary battery modules.

[0003] Due to the complex operating conditions and environments of secondary battery packs, if heat cannot be quickly conducted away from the pack, the internal temperature will rise, directly impacting its lifespan and safety. Furthermore, electric vehicles operate in harsh environments with high frequency of use, placing even stricter requirements on the secondary battery packs and their internal power batteries. Uniform temperature distribution within both the pack and battery is crucial. Current technology is insufficient to meet the stringent requirements for external protection and shock resistance of secondary battery packs. Therefore, resolving the thermal issues of secondary battery packs has become an urgent problem for manufacturers.

[0004] Furthermore, to make the secondary battery module compact while meeting requirements, multiple batteries are usually connected in series. To reduce the risk of damage due to movement during use, fixing components are typically installed on the outside of the battery, such as sleeves for cylindrical batteries. However, if the gap between the sleeve and the battery is too small, the battery is difficult to install; if the gap is too large, it is difficult to maintain a secure hold. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a secondary battery module, a secondary battery pack, and an assembly method for the secondary battery module. The secondary battery module can effectively position and fix the battery and install the battery, which is conducive to the rapid development of electric vehicles.

[0006] To achieve the above objectives, the first aspect of the present invention provides a secondary battery module, comprising a plurality of batteries connected in series along the same direction and a first tube accommodating the plurality of batteries, wherein the first tube is recessed inward at the junction of each adjacent battery to form an annular groove, the depth of the annular groove being greater than the distance between the first tube and the battery.

[0007] In the secondary battery module of this invention, the first tube is recessed inward at the junction of each adjacent battery to form an annular groove, and the depth of the annular groove is greater than the distance between the first tube and the battery. Therefore, the annular groove acts as a limiting component, which can tighten and fix the battery, thereby preventing the battery from moving within the first tube. In addition, since the annular groove will be provided later, the gap between the first tube and the battery can be set to be wider before the battery is installed to facilitate battery installation.

[0008] As one technical solution of the present invention, the depth of the annular groove is 0.05 to 2.00 mm.

[0009] As a technical solution of the present invention, a second tube is sleeved outside the first tube, and the first tube and the second tube together form a first through-cavity surrounding the plurality of batteries. Coolant flows through the first through-cavity parallel to the series connection direction of the batteries. The flow of coolant through the first through-cavity formed by the first tube and the second tube, parallel to the series connection direction of the batteries, allows for 360° all-around heat dissipation from the outside of the batteries. This method provides uniform heat dissipation, high heat dissipation efficiency, and prevents a rapid spread of heat from a single battery to adjacent batteries, thus avoiding impact on the entire secondary battery pack.

[0010] As one technical solution of the present invention, the battery is a cylindrical battery, and both the first tube and the second tube are hollow cylindrical tubes.

[0011] As one technical solution of the present invention, the first tube and the second tube are on the same rotational central axis.

[0012] A second aspect of the present invention provides a secondary battery pack, including a first housing, a second housing disposed below the first housing, and the aforementioned secondary battery module. The direction from the first housing to the second housing is defined as a first direction. The first housing and the second housing enclose a plurality of isolated second through cavities. The central axis of the second through cavity is perpendicular to the first direction. Each second through cavity contains a single secondary battery module. The central axis of the second through cavity is parallel to the series connection direction of the batteries.

[0013] The secondary battery module of this invention is housed within a second hollow cavity formed by the enclosing of a first housing and a second housing. This means the secondary battery module is completely enclosed by the first and second housings, reducing the risk of shaking, shifting, or damage during use. Furthermore, the arrangement of the first and second housings enhances the overall strength of the secondary battery pack. The series connection direction of the batteries is parallel to the central axis of the second hollow cavity and perpendicular to the first direction. Therefore, the batteries are placed sideways within the secondary battery pack, which alleviates stress on the batteries and increases the usability of both the batteries and the secondary battery module. Simultaneously, the sideways placement of the batteries facilitates the subsequent installation of wiring harnesses, isolation plates, BMS, and other components.

[0014] As a technical solution of the present invention, the first box body facing the second box body is provided with a plurality of isolated first slots, and the second box body facing the first box body is provided with a plurality of second slots corresponding to the positions of the first slots, and the corresponding first slots and second slots enclose to form the second through cavity.

[0015] As a technical solution of the present invention, the cross-sectional shape of the first slot in the first direction is semi-circular, and the cross-sectional shape of the second slot in the first direction is semi-circular.

[0016] As a technical solution of the present invention, the secondary battery module and the cavity wall of the second through cavity are fitted with a clearance.

[0017] A third aspect of the present invention provides a method for assembling a secondary battery module, comprising connecting multiple batteries in series in the same direction and housing them in a first tube, and then pressing the first tube inward at the joints of each adjacent battery to form an annular groove that can be compressed and fixed to the multiple batteries.

[0018] When assembling the secondary battery module of the present invention, it is first connected in series in the first tube and then the first tube is squeezed at the corresponding position to form an annular groove that compresses and fixes the battery. This method is simple and effective. Using this method can not only fix the battery, but also facilitate the assembly of the battery in the first tube.

[0019] As a technical solution of the present invention, it further includes forming the annular groove and then sleeved a second tube on the outside of the first tube, and the first tube and the second tube together form a first through cavity surrounding the plurality of batteries. Attached Figure Description

[0020] Figure 1 This is a perspective view of an embodiment of the secondary battery pack of the present invention.

[0021] Figure 2 This is a partial perspective view of an embodiment of the secondary battery pack of the present invention.

[0022] Figure 3 This is a partial top perspective view of an embodiment of the secondary battery pack of the present invention.

[0023] Figure 4 This is a partial side view of an embodiment of the secondary battery pack of the present invention.

[0024] Figure 5 for Figure 4 A partial exploded view.

[0025] Figure 6 This is a perspective view of an embodiment of the secondary battery module of the present invention.

[0026] Figure 7 for Figure 6 A cross-sectional view along the AA direction.

[0027] Figure 8 for Figure 6 A cross-sectional view along the BB direction.

[0028] Figure 9 This is a flowchart of the assembly method of the secondary battery module of the present invention.

[0029] Component Symbol Explanation

[0030] 100 - Secondary battery pack; 10 - First housing; 11 - First slot; 30 - Second housing; 31 - Second slot; 50 - Secondary battery module; 51 - Battery; 53 - First tube; 55 - Second tube; 57 - Annular groove; 59 - Third component; 71 - First main output terminal; 73 - Second main output terminal; 91 - Water inlet; 93 - Water outlet; D1 - First direction; D2 - Series connection direction of batteries; S1 - Second through cavity; S2 - First through cavity; T - Depth; d - Distance between the first tube and the battery Detailed Implementation

[0031] To better illustrate the purpose, technical solution, and beneficial effects of this invention, the invention will be further described below in conjunction with the accompanying drawings. It should be noted that the structures shown in the following drawings are further explanations of this invention and should not be construed as limiting it.

[0032] The secondary battery pack of this invention can be used in electric vehicles, lawnmowers, sweepers, energy storage power stations, and other electrical facilities, and is especially suitable for electric vehicles. When used in vehicles, one or more secondary battery packs can be arranged in a matrix to form a battery cluster and installed in a base located under the vehicle body.

[0033] The secondary battery pack of the present invention will now be further described with reference to the accompanying drawings. Figures 1-5As shown, the secondary battery pack 100 includes a first housing 10, a second housing 30 located below the first housing 10, and secondary battery modules 50. Multiple secondary battery modules 50 are arranged in a matrix, leading to a first total output terminal 71 and a second total output terminal 73. The terminals on the battery modules 50 can be connected to the total output terminal via connecting pieces or other components to achieve electrical output. The specific connection can be a common industry practice, which is not the focus of this invention and will not be described in detail here. The battery pack 100 may have an inlet 91 and an outlet 93 at the outlets of the first total output terminal 71 and the second total output terminal 73, which connect to cooling components in the battery modules 50. The first housing 10 and the second housing 30 can be matched and connected to components of a vehicle base, or used directly as the chassis of a vehicle base. The direction from the first housing 10 to the second housing 30 is defined as the first direction D1. The first housing 10 and the second housing 30 enclose and form multiple isolated second through-cavities S1. The central axis of the second through-cavity S1 is perpendicular to the first direction D1. Each second through-cavity S1 contains a single secondary battery module 50. The second through-cavity S1 has a through-structure and is connected to the outside. The central axis of the second through-cavity S1 is parallel to the series connection direction D2 of the batteries 51. The secondary battery module 50 is housed in the second through-cavities S1 formed by the first housing 10 and the second housing 30, meaning that the secondary battery module 50 is wrapped by the first housing 10 and the second housing 30. This reduces the risk of the secondary battery module 50 shaking, shifting, or being damaged during use. At the same time, the arrangement of the first housing 10 and the second housing 30 increases the strength of the entire secondary battery pack 10. The series connection direction D2 of the battery 51 is parallel to the central axis of the second cavity S1 and perpendicular to the first direction D1. Therefore, the battery 51 is placed on its side in the secondary battery pack 10, which can alleviate the stress on the battery 51 and thus increase the usability of the battery 51 and the secondary battery module 50.

[0034] Furthermore, such as Figures 4-5 As shown, the first housing 10 has multiple isolated first slots 11 facing the second housing 30. The second housing 30 has multiple second slots 31 facing the first housing 10, corresponding to the positions of the first slots 11. The corresponding first slots 11 and second slots 31 enclose to form a second hollow cavity S1. The walls of the secondary battery module 50 and the second hollow cavity S1 are fitted with a clearance to improve heat dissipation efficiency and volume space utilization.

[0035] Continue as Figures 6-8As shown, the secondary battery module 50 includes multiple batteries 51 connected in series along the same direction. A first tube 53 housing the multiple batteries 51 and a second tube 55 sleeved over the first tube 53 are also included. The multiple batteries 51 can be connected by wires 59 or by connecting the terminals of each battery 51 in series. The first tube 53 is recessed inward at the contact points of adjacent batteries 51 to form an annular groove 57. The depth T of the annular groove 57 is greater than the distance d between the first tube 53 and the battery 51. The multiple batteries 51 can be connected by a third component 59 (such as wires, connecting pieces, etc.) or by connecting the terminals of each battery 51 in series by bolts, laser welding, etc. Therefore, there is a certain gap at the contact points of adjacent batteries 51, which provides space for the first tube 53 to be recessed inward at the gap to form the annular groove 57. The annular groove 57 can be formed by extrusion (such as spin extrusion) after multiple batteries 51 are inserted into the first tube 53. Since the annular groove 57 can be used to compress and fix the batteries 51, the interval d between the first tube 53 and the batteries 51 can be set to be relatively wide (such as 0.03 to 0.10 mm) to facilitate battery installation. The depth T of the annular groove 57 is 0.05 to 2.00 mm, which can ensure both the compression and fixing of the batteries 51 and maintain the strength of the first tube 53.

[0036] A second tube 55 is fitted around the outside of the first tube 53, and the first tube 53 and the second tube 55 together form a first through-cavity S2 surrounding multiple batteries 51. Coolant flows through the first through-cavity S2 along the series connection direction D2 parallel to the batteries 51. The first through-cavity S2 has openings at both ends along the series connection direction D2, allowing coolant to flow in from one opening and out from the other, thus facilitating heat exchange and dissipating heat. The first through-cavity S2, formed by the first tube 53 and the second tube 55, allows for 360° all-around heat dissipation of the batteries 51, resulting in uniform and efficient heat dissipation. The first through-cavity S2 connects to an inlet 91 and an outlet 93. After entering through the inlet 91, the coolant is distributed to each of the first through-cavities S2, flows through each first through-cavity S2, and then converges to flow out of the battery pack 100 through the outlet 93. The battery pack 100 can be equipped with a flow divider and a flow combiner to achieve the distribution and collection of coolant at both ends of the first through-hole S2. The flow divider and flow combiner can be common structures on the market, which are not the focus of this invention, and will not be described in detail here. The coolant can be, but is not limited to, a water / ethylene glycol mixture, silicone oil, or silicone grease. Except for electrical connections, the secondary battery modules 50 of this invention can be independently integrated into the secondary battery pack, so that abnormal secondary battery modules 50 can be repaired or replaced individually during use. In actual use, an explosion-proof valve, a PTC temperature controller, etc. can be installed at one end of the secondary battery module 50 to provide safety protection and abnormal monitoring for individual secondary battery modules 50. The explosion-proof valve, PTC temperature controller, etc., can be installed or not installed on each battery 51 according to the actual situation.

[0037] The battery 51 of this invention can be a square battery, an arc-shaped battery, a blade battery, or a cylindrical battery. Preferably, the battery 51 is a cylindrical battery, and both the first tube 53 and the second tube 55 are hollow circular tubes. For cylindrical batteries, this heat dissipation method results in higher heat dissipation efficiency, the annular groove 57 is easier to process, and the first tube 53 and the second tube 55 occupy less volume, making it easier for coolant to flow through the first through cavity S2. For the secondary battery pack 100 where the battery 51 is a cylindrical battery, the cross-sectional shape of the first slot 11 in the first direction D1 is semi-circular, and the cross-sectional shape of the second slot 31 in the first direction D1 is also semi-circular. Of course, based on the battery 51 being a square battery, an arc-shaped battery, or a blade battery, or other battery shapes, the cross-sectional shapes of the first slot 11 and the second slot 31 in the first direction D1 are also set to match the shape of the battery 51, thereby improving the heat dissipation efficiency of the secondary battery pack 100.

[0038] It should be further noted that the first tube 53 and the second tube 55 share the same rotation axis, ensuring uniform heat dissipation and preventing thermal runaway caused by localized heat surges. The battery 51 and the first tube 53 are fitted with a clearance to improve heat dissipation efficiency and volume space utilization. The first tube 53 and the second tube 55 can be made of metals such as aluminum, copper, or stainless steel, or insulation materials such as polyurethane foam, polystyrene board, EPS, XPS, phenolic foam, polypropylene, or ceramics. Preferably, the second tube 55 has stronger insulation properties, and the first tube 53 has stronger thermal conductivity.

[0039] The assembly method of the secondary battery module of the present invention can be as follows: Figure 9 As shown, the process includes steps (a) connecting multiple batteries 51 in series along the same direction and housing them in a first tube 53; step (b) pressing the first tube 53 inward at the junctions of adjacent batteries 51 to form an annular groove 57 that can compress and fix the multiple batteries 51; and step (c) fitting a second tube 55 over the outside of the first tube 53, with the first tube 53 and the second tube 55 forming a first through-cavity S2 surrounding the multiple batteries 51. The series connection between the multiple batteries 51 can be achieved through a third component 59 (such as a wire, connecting piece, etc.) or by directly connecting the terminals of each battery 51 in series using bolts, laser welding, etc. Using other extrusion methods such as spin forming can indent the first tube 53 inward, thereby limiting the distance between the first tube 53 and the batteries 51, and the formed annular groove 57 can compress and fix the batteries 51. A second tube 55 is fitted over the outside of the first tube 53, and the two together form a first through cavity S2 surrounding multiple batteries 51. Coolant can flow through the first through cavity S2 to dissipate heat from the batteries 51. This assembly method is simple and effective, both fixing the batteries 51 and facilitating their assembly within the first tube 53.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A secondary battery module, characterized in that, It includes a plurality of batteries connected in series in the same direction and a first tube for accommodating the plurality of batteries. The first tube is recessed inward at the junction of each adjacent battery to form an annular groove. The depth of the annular groove is greater than the distance between the first tube and the battery.

2. The secondary battery module according to claim 1, characterized in that, A second tube is sleeved on the outside of the first tube, and the first tube and the second tube together form a first through cavity surrounding the plurality of batteries. Coolant flows through the first through cavity in a direction parallel to the series connection of the batteries.

3. The secondary battery module according to claim 2, characterized in that, The battery is a cylindrical battery, and both the first tube and the second tube are hollow cylindrical tubes.

4. The secondary battery module according to claim 2, characterized in that, The first tube and the second tube share the same rotation axis.

5. A secondary battery pack, characterized in that, The device includes a first housing, a second housing located below the first housing, and a secondary battery module according to any one of claims 1 to 4. The direction from the first housing to the second housing is defined as a first direction. The first housing and the second housing enclose a plurality of isolated second through-cavities. The central axis of the second through-cavities is perpendicular to the first direction. Each second through-cavity contains a single secondary battery module. The central axis of the second through-cavities is parallel to the series connection direction of the batteries.

6. The secondary battery pack according to claim 5, characterized in that, The first box body has multiple isolated first slots facing the second box body, and the second box body has multiple second slots facing the first box body that correspond to the positions of the first slots. The corresponding first slots and second slots enclose and form the second through cavity.

7. The secondary battery pack according to claim 6, characterized in that, The first slot has a semi-circular cross-sectional shape in the first direction, and the second slot has a semi-circular cross-sectional shape in the first direction.

8. The secondary battery pack according to claim 5, characterized in that, The secondary battery module and the cavity wall of the second through cavity are fitted with a clearance.

9. A method for assembling a secondary battery module, characterized in that, The method involves sequentially connecting multiple batteries in the same direction and housing them in a first tube, then pressing the first tube inward at the joints of adjacent batteries to form an annular groove that can compress and fix the multiple batteries.

10. The assembly method of the secondary battery module according to claim 9, characterized in that, It also includes forming the annular groove and then sleeve a second tube on the outside of the first tube, and the first tube and the second tube together form a first through cavity surrounding the plurality of batteries.

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