A battery pack

Abstract

The application relates to a battery pack, comprising a shell, a plurality of battery cells accommodated in the shell, a battery cell connecting piece mounted at the end of the battery cell, and a circuit board connected to the battery cell, the plurality of battery cells being connected in series and / or parallel through the battery cell connecting piece; the battery cell connecting piece has a welding portion connected to the battery cell and a connecting portion connected to the circuit board, the welding portion and the connecting portion are in different planes, and the battery pack further comprises a paper stopper connected to the end face of the battery cell connecting piece, the paper stopper being attached to the welding portion and the connecting portion. The application can reduce the technical problems caused by incomplete coverage of the paper stopper in the prior art battery pack.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] The battery pack's internal cell components also require exposed connecting plates to be covered with protective paper to provide dust and water protection. This is especially important when operating in humid environments, as the paper must prevent conductive media from contacting the cell components. Currently, mainstream protective paper typically uses red steel paper or ordinary foam to physically shield the connecting plate area of ​​the battery cells.

[0003] However, traditional paper baffles do not provide complete coverage, are highly absorbent, and have difficulty in quickly removing moisture, resulting in the surface of the connecting piece being constantly damp. Under extreme conditions, this may lead to electrochemical corrosion or micro-short circuits. Utility Model Content

[0004] In view of the above, it is necessary to provide a battery pack that can reduce the technical problems caused by incomplete paper cover coverage in existing battery packs.

[0005] This application provides a battery pack, including a housing, a plurality of battery cells housed in the housing, a battery cell connector mounted on the end of the battery cells, and a circuit board connected to the battery cells. The plurality of battery cells are connected in series and / or in parallel via the battery cell connector. The battery cell connector has a welding portion mounted on the battery cell and a connecting portion extending from the welding portion toward the circuit board. The plane in which the welding portion is located and the plane in which the connecting portion is located are not on the same plane. The battery pack also includes a baffle connected to the end face of the battery cell connector. The baffle is attached to at least a portion of the welding portion and the connecting portion.

[0006] In the battery pack of this application, by simultaneously attaching the baffle to the welding part (electrical contact area) and the connection part (circuit conduction area), three-dimensional coverage of the cell connector with the non-planar structure can be achieved. When there is a voltage difference between the cell connectors, this design can physically isolate the accumulation of dust and moisture in the charged non-planar gap and block the micro-current path formed by environmental pollutants. This can prevent problems such as electrochemical corrosion or micro-short circuit risk caused by the inability of traditional planar baffles to completely cover the three-dimensional structure.

[0007] In some embodiments, the battery pack further includes a cell holder, with at least one cell disposed in the cell holder, the cell holder having openings corresponding to the number of cells, and the cells being connected to welded portions of cell connectors through the openings.

[0008] In some embodiments, the cell connector is in the form of a sheet, and the cell connector also has an intermediate portion connected between the welding portion and the connecting portion, the intermediate portion being disposed in conform to the surface of the cell bracket, and the welding portion and the cell bracket together covering both sides of the cell.

[0009] In some embodiments, the battery cell, battery cell bracket, and battery cell connector are defined as a battery cell assembly, and a circuit board is disposed on one side of the battery cell assembly and is used to control the discharge or charging of the battery cell.

[0010] In some embodiments, the paper baffle includes a main body region and a first folded region connected to the main body region. The first folded region is rectangular. The main body region is attached to one end face of the battery cell assembly, and the first folded region is attached to the side of the battery cell assembly on which the circuit board is disposed by means of folding.

[0011] In some embodiments, the baffle includes a main region and a second folded region extending outward from the main region. The second folded region is rectangular. The main region is attached to one end face of the battery cell assembly, and the second folded region is attached to an adjacent side of the battery cell assembly on which the circuit board is disposed by means of folding.

[0012] In some embodiments, the baffle includes a main region and a third region extending outward from the main region, one side of the battery cell assembly is wavy, the third region is wavy to match the wavy shape, and the main region and the third region are attached to one end face of the battery cell assembly.

[0013] In some embodiments, the cell support has at least one protrusion, and the paper stop has a number of notches that match the protrusion and are adapted to the shape of the protrusion.

[0014] In some embodiments, the paper stop is made of a plastic-based material or a hydrophobic material.

[0015] In some embodiments, the paper backing is attached to the surface of the cell connector by an adhesive backing, which is a plastic-based material or a hydrophobic material. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a charging scenario for a battery pack according to an embodiment of this application.

[0017] Figure 2 This is an overall schematic diagram of the battery pack according to an embodiment of this application.

[0018] Figure 3 This is a schematic diagram of a portion of the internal structure of the battery pack according to an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the structure of the battery cell assembly according to an embodiment of this application.

[0020] Figure 5 This is a schematic diagram of the structure of a conductive terminal from one perspective of an embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the structure of a conductive terminal from another perspective of an embodiment of this application.

[0022] Figure 7This is a schematic diagram of the structure of a conductive terminal from another perspective of an embodiment of this application.

[0023] Figure 8 This is a schematic diagram of the structure of a battery cell connector from one perspective of an embodiment of this application.

[0024] Figure 9 This is a schematic diagram of the structure of the battery cell connector from another perspective of an embodiment of this application.

[0025] Figure 10 This is a schematic diagram showing the location distribution of the convex hull solder joints in an embodiment of this application.

[0026] Figure 11 This is a schematic diagram showing the location distribution of the convex hull solder joints according to another embodiment of this application.

[0027] Figure 12 This is a schematic diagram showing the positional relationship between the convex solder joint and the battery cell in an embodiment of this application.

[0028] Figure 13 This is a side view of the battery cell connector according to an embodiment of this application.

[0029] Figure 14 This is an assembly diagram of the battery cell bracket, battery cell connector and circuit board according to an embodiment of this application.

[0030] Figure 15 This is a schematic diagram of the structure of the battery cell support according to an embodiment of this application.

[0031] Figure 16 This is a schematic diagram of the circuit board structure according to an embodiment of this application.

[0032] Figure 17 This is a schematic diagram showing the position of the paper baffle covering the battery cell assembly from one perspective of an embodiment of this application.

[0033] Figure 18 This is a schematic diagram of the paper stop according to an embodiment of this application.

[0034] Figure 19 This is a schematic diagram of the folded state of the paper stop according to an embodiment of this application.

[0035] Figure 20 This is a schematic diagram of the position of the paper baffle covering the battery cell assembly from another perspective of an embodiment of this application.

[0036] Explanation of main component symbols 1. Battery pack; 2. Charger; 10. Cell assembly; 11. Housing; 12. Cell; 13. Conductive terminal; 14. Cell connector; 15. Cell support; 16. Circuit board; 17. Sheath; 18. Type I current-carrying element; 19. Type II current-carrying element; 120. Laser welding pattern; 121. Central region; 122. Transition region; 123. Edge region; 130. First plane; 131. Main body; 132. Terminal part; 140. Raised solder joint; 141. First cell connector; 142. Second cell connector; 151. Isolator; 52. Opening; 153. Protrusion; 154. Positioning part; 161. Substrate; 162. First through hole; 163. Second through hole; 164. Positioning port; 170. Main body area; 171. First folded area; 172. Second folded area; 173. Third area; 1320. Groove; 1321. Transition part; 1322. Clamping part; 1323. Guide part; 1401. Flow channel; 1402. Welding protrusion; 1403. Welding part; 1404. Connecting part; 1405. Middle part; 1406. Pin part; 1701. Notch.

[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0038] In the description of the embodiments in this application, the words "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary," "or," and "for example" is intended to present the relevant concepts in a specific manner.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be understood that, unless otherwise stated, " / " in this application means "or". For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. "At least one" refers to one or more. "More than one" refers to two or more. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, and a, b, and c (seven cases).

[0040] It should also be noted that the terms "first" and "second" in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0041] Current battery packs primarily use ordinary cylindrical cells. These cells have a significantly lower discharge rate than tabbed cells (also known as "all-tab cells"). Furthermore, existing battery packs generally employ cost-effective and durable structures, with lower requirements for the conductivity, heat dissipation, and charge / discharge performance of the main circuit current-carrying components. Many existing battery packs can meet requirements using common materials and basic designs, without much special design for enhancing conductivity, improving heat dissipation, or preventing short circuits. Specifically, the following aspects are relevant: First, battery packs supporting fast charging need to input more energy per unit time, directly relying on the cell chemistry and thermal management capabilities. High-rate charging triggers temperature protection mechanisms, thus interrupting charging. Conventional cylindrical cell battery packs are limited by cell internal resistance and heat dissipation efficiency, generally controlling the charging rate to within 2C, and extending charging time through optimized thermal management. However, the internal resistance thermal effect is significant during high-rate charging of general-purpose cells, with the temperature rise rate far exceeding the heat dissipation capacity, forcing the system to reduce the charging current or trigger protection, making it difficult to achieve continuous high-speed charging.

[0042] Secondly, the conductive terminals of the battery pack, as external current interaction interfaces, must possess high conductivity, mechanical strength, and vibration resistance. In high-current applications, the contact resistance of the conductive terminals directly affects temperature rise and discharge efficiency. Ordinary conductive terminals use copper alloy materials with moderate hardness, forming elastic clamping contacts through a fish-mouth structure to balance conductivity requirements and structural strength. However, it is difficult to optimize the conductivity, hardness, and rust resistance of the aforementioned conductive terminal materials in a coordinated manner. Insufficient conductivity of high-hardness materials leads to high contact resistance, resulting in significant local temperature rise during high-current discharge. Alternatively, the elastic structure of the conductive terminal is prone to wear and deformation under long-term vibration, leading to poor rust resistance.

[0043] Furthermore, after cell welding, it is essential to ensure stable conductivity between the cell connector and the cell casing while avoiding damage to the internal structure of the cell. Omni-tab cells may have specific limitations on the welding position layout due to the presence of a laser pre-welded area. General-purpose cell connectors employ a centrally symmetrical four-protrusion welding method, with the protrusions typically distributed near the center of the cell casing (radius approximately 1mm to 3mm), achieving contact conductivity through a projection hull welding process. However, the central area welding of this general-purpose method easily overlaps with the pre-welded area of ​​the omni-tab cell. Multiple welding operations may affect the internal welding quality of the omni-tab cell. Additionally, an overly concentrated protrusion distribution can lead to superimposed welding stress, reducing connection reliability. Therefore, this general-purpose welding method is insufficient to meet the welding requirements of omni-tab cells.

[0044] Furthermore, in high-performance battery pack designs, the circuit board and metal cell connectors need to share the current transmission function. Due to potential differences between different cell connectors or circuit board areas, it is crucial to strictly prevent short circuits between energized components. Conventional battery packs achieve physical isolation between energized components by leaving safe distances or filling them with insulating adhesive, relying on structural space layout to avoid short circuit risks. However, the aforementioned safe distance design is still insufficient to address short circuits caused by dust accumulation, and the curing process of the insulating adhesive is prone to fluctuations. Long-term use may lead to insulation failure due to vibration and aging, increasing the risk of micro-short circuits.

[0045] Finally, the battery pack's internal cell components also need to be covered with protective paper to provide shock absorption, dust protection, and waterproofing. In humid environments, the protective paper must avoid becoming a conductive medium. Currently, mainstream protective paper typically uses red steel paper or ordinary foam to provide physical protection by covering part of the cell's connecting area. However, red steel paper provides incomplete coverage and lacks shock absorption; while ordinary foam paper is highly absorbent and difficult to wick away quickly, leaving the cell connecting surface constantly damp, which under extreme conditions may lead to electrochemical corrosion or micro-short circuits.

[0046] Therefore, this application provides a battery pack and related components to overcome the shortcomings of the prior art. Some embodiments will be described below with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0047] Figure 1 This is a schematic diagram of the charging scenario of battery pack 1 according to an embodiment of this application. Figure 2 This is an overall schematic diagram of the battery pack 1 according to an embodiment of this application. Figure 3 This is a schematic diagram of a portion of the internal structure of the battery pack 1 according to an embodiment of this application. Figure 4 This is a schematic diagram of the structure of the battery cell assembly 10 according to an embodiment of this application.

[0048] like Figures 1 to 4As shown, this application provides a battery pack 1 that is compatible with a charger 2, meaning it can be plugged into the charger 2 for charging. The battery pack 1 may include a housing 11, battery cells 12 installed within the housing 11, and conductive terminals 13 connected to the battery cells 12. The battery cells 12 can be omni-tab cells. The conductive terminals 13 are detachably connected to the plug terminals of the charger 2, and the electrical energy of the omni-tab cells is input via the conductive terminals 13. The charging rate of the omni-tab cells is 2C to 4C. In the battery pack 1 of this application, by using omni-tab cells with a charging rate range of 2C to 4C, the battery pack 1 possesses a high-rate charging capability. The low internal resistance of the omni-tab cells weakens the electrochemical polarization effect during high current input, significantly reducing heat accumulation during charging. Therefore, it can support continuous charging at higher rates without triggering temperature control protection, shortening the user's charging waiting time, thereby reducing the problem of fast charging interruption due to temperature rise in the prior art.

[0049] In some embodiments, the standard discharge current of the omnipolar cell is 0.8A. The low internal resistance of the omnipolar cell enables it to maintain a more stable voltage platform under normal loads.

[0050] In some embodiments, the charging current of the omni-tab battery cell is 8A, the maximum continuous charging current of the omni-tab battery cell is 14A, and the AC internal resistance of the omni-tab battery cell is less than or equal to 4.0mΩ (measured at AC 1KHz). By limiting the charging current, maximum continuous current, and AC internal resistance, the AC internal resistance can be reduced to suppress the Joule heating effect under high current operation. This, combined with the thermal diffusion advantage of the omni-tab structure, makes the heat of the battery cell 12 controllable in the charging range of 8A to 14A, reducing the limitation of charging rate due to temperature rise. This ensures the feasibility of fast charging and high power output.

[0051] In some embodiments, the omnipolar cell can be an 18650 specification cell 12, with a diameter of 16mm to 20mm and a length of 63mm to 67mm.

[0052] In some embodiments, the omnipolar cell can also be a 21700 specification cell 12, with a diameter of 19mm to 23mm and a length of 68mm to 72mm.

[0053] In some embodiments, as described above, the battery pack 1 may include a housing 11, a battery cell 12 mounted on the housing 11, and a circuit board 16 and conductive terminals 13 connected to the battery cell 12. The battery pack 1 receives current through the conductive terminals 13, which are configured to electrically connect to the plug terminals of a power tool.

[0054] Based on the above, this application also provides a conductive terminal 13. Figure 5 This is a schematic diagram of the structure of the conductive terminal 13 from one perspective of an embodiment of this application. Figure 6 This is a schematic diagram of the structure of the conductive terminal 13 from another perspective of an embodiment of this application.

[0055] like Figure 5 As shown, it may include a main body 131 and terminal portions 132 extending outward from the end of the main body 131. At least a portion of the terminal portions 132 is made of a chromium-zirconium-copper alloy, and the surface of the terminal portions 132 is plated with nickel. In the conductive terminal 13 of this application, by using a chromium-zirconium-copper alloy substrate and plating with nickel, the corrosion resistance of the terminal surface can be enhanced while maintaining high conductivity. The high conductivity of the chromium-zirconium-copper alloy can reduce current transmission loss, while the nickel plating can isolate the corrosion of environmental moisture and oxygen, reducing the problem of increased contact resistance caused by oxidation of traditional copper alloys in vibration and humid environments. This can fundamentally suppress abnormal temperature rise during high current discharge and improve wear resistance and rust prevention.

[0056] In some embodiments, the Vickers hardness of the chromium-zirconium-copper alloy can be from 150 HV to 220 HV, the thermal conductivity can be from 200 W / (m·K) to 400 W / (m·K), and the electrical conductivity can be from 65% to 90%. Further, in some embodiments, the electrical conductivity of the chromium-zirconium-copper alloy can be from 70% to 85%. In this case, by limiting the hardness, thermal conductivity, and electrical conductivity of the chromium-zirconium-copper alloy to specific ranges, the mechanical strength and electrothermal performance of the conductive terminal 13 can be synergistically optimized. Higher hardness ensures that the clamping structure of the conductive terminal 13 resists deformation during frequent insertion and removal, while the matched thermal / electrical conductivity ensures rapid heat dissipation when a large current passes through, reducing local overheating and protection shutdown, thereby improving the stability of high-rate discharge of the battery pack 1.

[0057] In some embodiments, such as Figure 6 As shown, the terminal portion 132 may include a transition portion 1321, a clamping portion 1322, and a guide portion 1323 extending from the main body portion 131. A plane parallel to the extension direction of the main body portion 131 and located between the two main body portions 131 is defined as the first plane 130. The transition portion 1321, the clamping portion 1322, and the guide portion 1323 can all be symmetrically arranged on both sides of the first plane 130. The two clamping portions 1322 gradually approach each other in the direction away from the main body portion 131, that is, the conductive terminal 13 can be arranged in a fish mouth shape. In this case, the symmetrical transition portion 1321, the clamping portion 1322, and the guide portion 1323 can form a progressive clamping channel, so that the insert terminal is adaptively pressed by the double clamping structure when inserted, which can increase the effective contact area. In addition, the tilt angle can optimize and reduce the insertion and extraction resistance. At the same time, the guide portion 1323 can mechanically correct the insert misalignment, thereby significantly reducing the risk of instantaneous disconnection under vibration conditions.

[0058] In some embodiments, the angle (R1) between the surface of the guide portion 1323 facing the first plane 130 and the first plane 130 can be in the range of 33° to 37°, and the angle (R2) between the plane where the transition portion 1321 is located and the first plane 130 can be in the range of 16° to 20°.

[0059] In some embodiments, the conductive terminal 13 can be used to insert a plug-in terminal, the clamping part 1322 is configured as a flat plate, and the two clamping parts 1322 are used to clamp the two sides of the plug-in terminal.

[0060] Figure 7 This is a schematic diagram of the structure of the conductive terminal 13 from another perspective of an embodiment of this application.

[0061] In some embodiments, such as Figure 7 As shown, the clamping part 1322 may have a groove 1320, which can divide the clamping part 1322 into multiple segments. In this case, the groove 1320 can divide the single-sided clamping part 1322 into multiple independent elastic units. When there is slight deformation or assembly tolerance of the insert terminal, each segment can deform independently to compensate for the positional deviation, reduce poor contact caused by uneven local force, and at the same time improve the overall elastic deformation capability of the clamping part 1322, reducing the probability of metal fatigue fracture.

[0062] In some embodiments, the thickness of the clamping portion 1322 is 0.4 mm to 0.8 mm, and the width of a single clamping portion 1322 is 3.3 mm to 3.7 mm, for example, as... Figure 7 As shown, the width D of a single clamping portion 1322 is 3.5 mm. In this case, the matching design of the thickness and width of the clamping portion 1322 can achieve a balance between mechanical strength and elasticity: if it is too thin, it is easy to deform and fail due to clamping force, while if it is too thick, the elasticity is insufficient; and the clamping portion 1322 with a specific width can ensure the maximum contact area, while reducing the uneven stress distribution caused by excessive width, thereby ensuring the continuous and stable current conduction capability of the conductive terminal 13 under vibration.

[0063] In some embodiments, the entire surface of the conductive terminal 13 is nickel-plated. Furthermore, the thickness of the nickel plating on the conductive terminal 13 is between 1 micrometer and 5 micrometers. In this case, the overall nickel plating of the conductive terminal 13 can form a complete anti-corrosion barrier, reducing oxidation weak points at cut edges or assembly gaps (where partial nickel plating easily leads to electrochemical corrosion in uncovered areas). The limited plating thickness (1 to 5 μm) ensures that a certain amount of anti-corrosion margin is maintained during frequent insertion and removal wear; too thin a layer will easily wear through and fail, while too thick a layer will increase resistance and reduce adhesion.

[0064] As described above, the battery pack 1 involved in the embodiments of this application may include a housing 11, a battery cell 12 mounted on the housing 11, and a circuit board 16 and conductive terminals 13 connected to the battery cell 12. In some embodiments, the battery pack 1 may further include a battery cell connector 14 connected to the battery cell 12. Based on this, the embodiments of this application also provide improvements to the battery cell connector 14, as follows.

[0065] Figure 8 This is a schematic diagram of the structure of the cell connector 14 from one perspective of an embodiment of this application. Figure 9 This is a schematic diagram of the structure of the cell connector 14 from another perspective of an embodiment of this application. Figure 10 This is a schematic diagram showing the positional distribution of the convex hull solder joints 140 in an embodiment of this application. Figure 11 This is a schematic diagram showing the positional distribution of the convex hull solder joints 140 according to another embodiment of this application.

[0066] In embodiments of this application, the cell connector 14 can conduct the current of the cell 12, such as... Figure 8 or Figure 9 As shown, the battery cell connector 14 may have multiple raised solder points 140, which may be symmetrically distributed around the center of the polarity end (e.g., negative terminal) of the battery cell 12. The polarity end is welded to the raised solder points 140, and the polarity end has laser welding marks 120. Figure 10 As shown, the minimum distance (d0) between the center of any convex weld point 140 and the laser welding pattern 120 is not less than 0.7 mm. In the battery pack 1 of this application, by limiting the minimum distance between the convex weld point 140 and the laser welding pattern 120 to 0.7 mm, the existing laser welding area of ​​the cell 12 can be physically avoided during welding, ensuring that the heat-affected zone of the convex weld does not overlap with the original welding structure of the cell 12. This can reduce the metallurgical stability of the laser welding pattern 120 of the polar end (negative electrode) of the cell 12 due to high temperature damage, and maintain the effective welding contact surface between the cell connector 14 and the cell 12 housing 11, thus eliminating the risk of secondary welding damage to the internal structure of the cell 12 from the root.

[0067] In some embodiments, such as Figure 10 As shown, the distance (d1) from the convex hull solder joint 140 to the center point of the polarity end can be greater than 2.5 mm and less than 4 mm. In this case, by limiting the convex hull solder joint 140 to an annular area 2.5 mm to 4 mm from the center of the polarity end, the soldering position avoids the sensitive central area of ​​the cell 12. This range satisfies the widest mechanical constraint of the solder joint distribution on the size of the soldering gun (if the distance is too small, the soldering gun cannot be operated), and also prevents the cell connector 14 from warping and becoming unstable due to the solder joint being too marginal (if the distance is too large, the support will be insufficient). This can enhance the reliability of the welding in terms of structural feasibility.

[0068] In other embodiments, such as Figure 11 As shown, the distance (d2) from the convex hull weld point 140 to the center point of the polarity end can be greater than 3 mm and less than 4 mm. Further limiting this basic distance range to 3 mm to 4 mm approaches the extreme balance between avoidance requirements and structural stability. This allows for enhanced warping resistance in the welded area by reducing the distance (closer weld points result in higher stiffness), while increasing the distance more thoroughly avoids the central sensitive area (reserving a larger thermal buffer space), achieving dual safety redundancy optimization.

[0069] In some embodiments, such as Figure 10 or Figure 11 As shown, the convex hull solder joints 140 can be distributed on the same circumference. In this case, the convex hull solder joints 140, through their axisymmetric distribution and mechanical support, can reduce the tendency of the battery cell connector 14 to deform due to the concentration of welding thermal stress, and optimize the stability of the electrical and mechanical connections. That is, the solder joints symmetrically distributed on the same circumference can form a uniform load-bearing structure. In addition, after the current is diverted by the current guide groove 1401, it is evenly transmitted to each solder joint along the circumferential path, which can eliminate single-point current overload.

[0070] In some embodiments, there may be four convex hull solder joints 140, which may be evenly distributed on both sides of the flow guide groove 1401. Prior to this, the flow guide groove 1401 undertakes the main current conduction function, and the symmetrical solder joints only provide auxiliary conduction and mechanical anchoring. This satisfies the high current conduction requirements (main load bearing of the trench) and avoids stress concentration by dispersing pressure at multiple points (solder joints provide auxiliary fixation), thereby achieving decoupling optimization of current carrying function and structural function.

[0071] Figure 12 This is a schematic diagram showing the positional relationship between the convex solder joint 140 and the battery cell 12 in an embodiment of this application.

[0072] In some embodiments, cell 12 can be a omnipolar cell, and as... Figure 12 The polar end of the shown cell 12 (typically circular in cross-section) may have a central region 121, an edge region 123 away from the central region 121, and a transition region 122 located between the central region 121 and the edge region 123. The convex hull solder joints 140 are distributed in the transition region 122. In this case, considering the characteristics of the central pre-welded area and the weak edge area of ​​the all-tab cell, the solder joints are confined to the transition region between the two. This not only keeps the laser weld heat-sensitive point (central region 121) at the center of the negative electrode, but also avoids the curvature abrupt change zone (edge ​​region 123) at the edge of the cell 12 casing 11. This maximizes the avoidance of potential damage to the structural integrity of the cell body while maintaining the welding strength.

[0073] In some embodiments, the omnipolar battery cell can be an 18650 type cell 12 or a 21700 type cell 12, with laser welding marks 120 distributed in the central region 121 or the edge region 123. In this case, by explicitly adapting to common cylindrical specifications such as 18650 / 21700 and allowing the welding marks to be distributed in the center or at the edge, the welding position avoidance rules can be made universal. Specifically, different sized battery cells 12 only need to dynamically adjust the avoidance logic according to the actual position of their pre-welded area (center or near the edge), without redesigning the solder joint layout of the battery cell connector 14, thus improving the cross-platform compatibility of the solution.

[0074] In some embodiments, there may be multiple cell connectors 14, for example, such as Figure 8 or Figure 9 As shown, the cell connector 14 may include a first cell connector 141 and a second cell connector 142. The first cell connector 141 and the second cell connector 142 can be connected to the cell 12 to correspond to different numbers of cells 12 and different series and parallel connection requirements of the cells 12. In addition, the shapes of the first cell connector 141 and the second cell connector 142 may be different.

[0075] In some embodiments, such as Figure 8 or Figure 9 As shown, the battery cell connector 14 can be formed with a straight groove 1401 that passes through the center of the polarity end.

[0076] In some embodiments, the cell connector 14 can be in the form of a sheet. The sheet-like cell connector 14 can fit tightly against the cell support 15 or the cell 12, thereby improving stability.

[0077] Figure 13 This is a side view of the battery cell connector 14 according to an embodiment of this application.

[0078] In some embodiments, such as Figure 13 As shown, the cell connector 14 may have a welding protrusion 1402 protruding toward the cell 12, and the convex weld point 140 may be disposed within the welding protrusion 1402. In this case, the welding protrusion 1402 protrudes toward the cell 12 to achieve zero-gap alignment. Specifically, the convex weld point 140 being completely embedded in the welding protrusion 1402 allows the welding pressure to be precisely and perpendicularly applied to the weld area, eliminating shear force; at the same time, the protruding structure forms a buffer transition zone between the weld point and the main body of the cell connector 14, suppressing the transmission of thermal deformation to the main body area 170 and ensuring controllable welding deformation.

[0079] In some embodiments, the battery cell 12 may include a battery cell body and a battery cell steel shell (not shown). The battery cell body is used to store electrical energy, and the battery cell steel shell covers the battery cell body. The battery cell connector 14 may include a positive electrode connector and a negative electrode connector. The negative electrode of the battery cell 12 is connected to the battery cell steel shell to form a negative terminal and then welded to the negative electrode connector. The positive electrode of the battery cell 12 is welded to the positive electrode connector. In this case, the coupling between the positive / negative electrode connectors and the battery cell steel shell allows the steel shell, as a negative electrode current carrier, to disperse the heat load (increasing the heat dissipation specific surface area). The independent welding of the positive electrode can avoid the potential coupling interference of the steel shell, forming a positive / negative dual-circuit physical isolation and reducing the probability of inter-electrode short circuit.

[0080] As described above, the battery pack 1 involved in the embodiments of this application may include a housing 11, a battery cell 12 mounted on the housing 11, a circuit board 16 connected to the battery cell 12, conductive terminals 13, and a battery cell connector 14 connected to the battery cell 12. In some embodiments, the battery pack 1 may further include a battery cell support 15, on which the battery cell 12 may be mounted. Based on this, the embodiments of this application also provide improvements to the battery cell support 15, as follows.

[0081] Figure 14 This is an assembly diagram of the battery cell bracket 15, battery cell connector 14 and circuit board 16 according to an embodiment of this application. Figure 15 This is a schematic diagram of the structure of the cell support 15 according to an embodiment of this application. Figure 16 This is a schematic diagram of the structure of the circuit board 16 in an embodiment of this application.

[0082] like Figure 14 As shown in the embodiments of this application, the battery pack 1 may further include a first type of current-carrying element 18 and a second type of current-carrying element 19 connected to the cell 12. The second type of current-carrying element 19 is different from the first type of current-carrying element 18. The first type of current-carrying element 18 is mounted at the end of the cell 12 and extends toward the second type of current-carrying element 19. The cell support 15 may have an axial direction intersecting the cell 12 (i.e., Figure 14 An insulating member 151 protrudes in the direction of (B-direction) and can be located on the path of the minimum creepage distance between the first type of current-carrying element 18 and the second type of current-carrying element 19. The minimum creepage distance refers to the shortest path distance between adjacent charged current-carrying elements that may lead to current breakdown through air or along an insulating surface. In the battery pack 1 of this application, the insulating member 151 protruding from the cell support 15 forcibly intervenes in the minimum creepage path between the first type of current-carrying element 18 (such as the cell connector 14) and the second type of current-carrying element 19 (such as the charged parts of the circuit board 16). By actively intervening in the electrical clearance using the insulating member 151, a safety redundancy is constructed within a limited space, thereby forming a physical isolation barrier. This directly blocks short circuits caused by dust or foreign object accumulation, reducing the failure risk of traditional methods that rely solely on distance or sealing.

[0083] In some embodiments, such as Figure 15 As shown, the cell support 15 may have an isolation member 151 protruding in a direction intersecting the extension direction of the cell 12. Specifically, the cell support 15 may have an isolation member 151 protruding in a direction perpendicular to the extension direction of the cell 12.

[0084] In some embodiments, as described above, the battery pack 1 may further include a circuit board 16 connected to the battery cell 12, a second type of current-carrying element 19 may be mounted on the circuit board 16, and a first type of current-carrying element 18 may be connected to the circuit board 16. After integrating the second type of current-carrying element 19 (such as a fuse element) into the circuit board 16, modular isolation of the charged components is achieved through cooperation with the isolator 151.

[0085] In some embodiments, such as Figure 16 As shown, the circuit board 16 may have a first direction (i.e. Figure 14 and Figure 16 The substrate 161 extends in the direction A) and a first through-hole 162 penetrates the substrate 161. The isolator 151 can be installed within the first through-hole 162. In this case, on the one hand, adding an insulating medium to the inner wall of the through-hole surrounds the isolator 151, which can extend the creepage distance; on the other hand, mechanical insertion can enhance structural stability. Thus, the nested structure of the isolator 151 and the through-hole of the circuit board 16 forms a double-protection mechanism, reducing creepage phenomena between current-carrying components.

[0086] In some embodiments, the extension direction of the isolator 151 may be perpendicular to the first direction, and the end of the isolator 151 may be chamfered. In this case, the chamfered design at the top of the isolator 151 can provide an assembly guiding function, allowing the circuit board 16 to slide into position along a predetermined trajectory, eliminating the risk of rigid collisions in precision assembly, ensuring that the isolator 151 passes through the through hole without damage, while maintaining the integrity of the creepage structure and reducing safety failures caused by installation deviations.

[0087] In some embodiments, the first through-hole 162 may be shaped to semi-enclose the first type of current-carrying element 18, and the shape of the isolator 151 may be adapted to the first through-hole 162. For example, both the first through-hole 162 and the isolator 151 may be "U" or "U". In this case, the contour matching between the semi-enclosed through-hole and the isolator 151 can form a customized isolation area for the contour of the first type of current-carrying element 18, or precisely construct an isolation band in a dense area of ​​the first type of current-carrying element 18 (such as when there are multiple first type of current-carrying elements 18), maximizing the use of space to improve local insulation strength, thereby reducing the layout waste problem of traditional uniform isolation.

[0088] In some embodiments, the height of the isolator 151 may be greater than the height of the first type of current-carrying element 18 and the second type of current-carrying element 19. In this case, the height difference between the isolator 151 and the current-carrying element can establish a height difference defense mechanism, thereby forming a vertical insulating safety layer to ensure that the isolator 151 can still maintain physical isolation when the current-carrying element is deformed by heat.

[0089] In some embodiments, such as Figure 16 As shown, the circuit board 16 may have a positioning port 164 penetrating the substrate 161, and at least a portion of the cell support 15 may extend toward the circuit board 16 to form a positioning portion 154 that matches the positioning port 164. In this case, the positioning port 164 can be inserted and matched with the positioning portion 154 of the cell support 15 to achieve assembly pre-correction, ensuring the absolute coaxiality of the through hole of the circuit board 16 and the isolator 151, eliminating the cumulative error of manual assembly, and ensuring that the isolator 151 accurately penetrates the first through hole 162 without damaging the circuit board 16, thereby reducing safety failures caused by installation defects.

[0090] In some embodiments, the first type of current-carrying element 18 can be the cell connector 14 involved in the embodiments of this application. The cell connector 14 can be disposed in close contact with the cell support 15 and at least part of the cell connector 14 can be electrically connected to the cell 12. The circuit board 16 can also have a second through hole 163 penetrating the substrate 161. The cell connector 14 can have a pin portion 1406 extending in a direction intersecting the first direction, and the pin portion 1406 can extend out of the second through hole 163. In this case, after the pin portion 1406 of the cell connector 14 extends out through the second through hole 163 of the circuit board 16, the pin portion 1406 only undertakes electrical connection, and the cell support 15 undertakes mechanical load. This can separate the current-carrying path from the support structure, thereby relieving the stress on the circuit board 16 and avoiding the situation where the connection point breaks due to vibration stress when using traditional solder joint connection. At the same time, the design of the pin portion 1406 can also reduce the encroachment on the creepage distance.

[0091] In some embodiments, the first type of current-carrying element 18 may be the cell connector 14 involved in the embodiments of this application. Specifically, in some embodiments, the first type of current-carrying element 18 may be the pin portion 1406 of the cell connector 14 involved in the embodiments of this application.

[0092] In some embodiments, such as Figure 8 , Figure 9 or Figure 13 As shown. The cell connector 14 may have a pin portion 1406 extending in a direction intersecting the first direction. Specifically, the cell connector 14 may have a pin portion 1406 extending in a direction perpendicular to the first direction.

[0093] In some embodiments, the second type of current-carrying element 19 can be at least one functional element selected from output terminals (such as conductive terminals 13 in the embodiments of this application), fuse elements, sensing elements, and discharge elements. In this case, for different functional current-carrying elements such as fuse elements (high heat generation), sensing elements (sensitive to signal interference), and output terminals (high current), potential isolation is uniformly achieved through the isolator 151, thereby reducing compatibility issues of mixed layout of multiple elements, and especially suppressing the electromagnetic interference and heat conduction effects of high-power elements on low-power elements.

[0094] In some embodiments, the second type of current-carrying element 19 is surface-mounted on the circuit board 16. Surface mount technology (SMT) allows the second type of current-carrying element 19 to be bonded to the circuit board 16 with zero gap, eliminating the risk of pin creepage of traditional through-hole components, significantly reducing the loss of creepage distance due to the height of the component itself, and enhancing the overall planar insulation consistency of the board.

[0095] In some embodiments, such as Figure 4 As shown, at least one battery cell 12 can be disposed within the battery cell support 15, and as Figure 15 The shown cell support 15 may have openings 152 corresponding to the number of cells 12, through which the cells 12 are welded to the cell connector 14 via the openings 152 at the welding portion 1403 (see [link]). Figure 13 In this case, the battery cell bracket 15 forms a stable assembly base with the battery cell 12 through the positioning effect of the opening 152 and the mechanical constraint of the battery cell 12. This can make the welding part 1403 of the battery cell connector 14 be subjected to uniform force, thereby ensuring that the welding positions of multiple battery cells 12 and battery cell connector 14 are accurately aligned, avoiding deformation or poor welding of the welding point due to displacement of the battery cell 12, and ensuring the structural stability of the high current transmission path.

[0096] In some embodiments, for ease of description, the battery cell 12, battery cell support 15, and battery cell connector 14 are defined as a battery cell assembly 10. The circuit board 16 may be disposed on one side of the battery cell assembly 10 and used to control the discharge or charging of the battery cell 12. In this case, placing the circuit board 16 on the side of the battery cell assembly 10 can shorten the conduction distance of the battery cell connector 14 from the solder portion 1403 to the control circuit, and the spatial design of the circuit board 16 being close to the battery cell assembly 10 can reduce energy loss in the main circuit.

[0097] As described above, the battery pack 1 involved in the embodiments of this application may include a housing 11, a battery cell 12 mounted on the housing 11, a circuit board 16 connected to the battery cell 12, conductive terminals 13, a battery cell connector 14 connected to the battery cell 12, and a battery cell bracket 15 for mounting the battery cell 12. In some embodiments, the battery pack 1 may further include a paper baffle 17, which can be used to cover the battery cell 12 and its related components (such as the battery cell connector 14). Based on this, the embodiments of this application also provide improvements to the paper baffle 17, as follows.

[0098] Figure 17 This is a schematic diagram showing the position of the paper baffle 17 covering the battery cell assembly 10 from one perspective of an embodiment of this application.

[0099] In the embodiments of this application, the cell connector 14 can be mounted on the end of the cell 12, and the circuit board 16 can be connected to the cell 12. The cells 12 are connected in series and / or in parallel via the cell connector 14. The cell connector 14 may have a soldering portion 1403 connected to the cell 12 and a connection portion 1404 connected to the circuit board 16 (see [link]). Figure 13 Furthermore, the plane containing the welding portion 1403 can be set opposite to the plane containing the connecting portion 1404. The baffle 17 can be connected to the end face of the cell connector 14, and as... Figure 17 The baffle 17 shown can be attached to the welding portion 1403 and the connecting portion 1404. In the battery pack 1 of this application, by attaching the baffle 17 to both the welding portion 1403 (electrical contact area) and the connecting portion 1404 (circuit conduction area), three-dimensional coverage of the non-planar cell connector 14 can be achieved. When there is a voltage difference in the cell connector 14, this design can physically isolate the accumulation of dust and moisture in the charged non-planar gap and block the micro-current path formed by environmental pollutants. This can prevent problems such as electrochemical corrosion or micro-short circuit risk caused by the inability of the traditional planar baffle 17 to completely shield the three-dimensional structure.

[0100] In some embodiments, as described above, the cell connector 14 may be in the form of a sheet, such as... Figure 13 As shown, the cell connector 14 may also have an intermediate portion 1405 connecting the welding portion 1403 and the connecting portion 1404. The intermediate portion 1405 is disposed in contact with the surface of the cell support 15, and the welding portion 1403 and the cell support 15 together cover both sides of the cell 12. In this case, the sheet-like cell connector 14 is attached to the surface of the cell support 15 through the intermediate portion 1405, forming a rigid stacked structure of "cell 12-cell support 15-cell connector 14". The intermediate portion 1405 is closely attached to the flat area of ​​the cell support 15, so that the deformation stress of the welding portion 1403 is transferred to the cell support 15 instead of being concentrated at the solder joint. This can prevent the solder joint cracking problem caused by thermal expansion during high current operation.

[0101] In other embodiments, such as Figure 13 As shown, the cell connector 14 may also have an intermediate portion 1405 connecting the two welded portions 1403, that is, an intermediate portion 1405 may also be present between the two welded portions 1403. The intermediate portion 1405 is disposed in contact with the surface of the cell support 15, and the welded portions 1403 and the cell support 15 together cover both sides of the cell 12.

[0102] Figure 18 This is a schematic diagram of the external shape of the paper stop 17 according to an embodiment of this application. Figure 19 This is a schematic diagram of the folded state of the paper stop 17 according to an embodiment of this application.

[0103] In some embodiments, such as Figure 18 and Figure 19 As shown, the baffle 17 may include a main body region 170 and a first folded region 171 connected to the main body region 170. The first folded region 171 may be rectangular. The main body region 170 may be attached to one end face of the battery cell assembly 10. The first folded region 171 may be attached to the side of the battery cell assembly 10 where the circuit board 16 is located by folding. In this case, the first folded region 171 covers the plane where the circuit board 16 is located by folding, forming an "L"-shaped protective cover. When the main body region 170 vertically protects the end face of the battery cell 12, the first folded region 171 simultaneously horizontally shields the surface of the battery cell assembly 10 where the circuit board 16 is located, preventing external dust from entering the battery cell assembly 10 through the junction gap between the end face and the side face, thereby improving the continuous insulation performance.

[0104] In some embodiments, such as Figure 18 and Figure 19 As shown, the baffle 17 may further include a main body region 170 and a second folded region 172 extending outward from the main body region 170. The second folded region 172 may be rectangular. The main body region 170 may be attached to one end face of the battery cell assembly 10, and the second folded region 172 may be attached to the adjacent side of the battery cell assembly 10 where the circuit board 16 is located by folding. In this case, the second folded region 172 covers the side of the battery cell assembly 10 (i.e., adjacent to the side where the circuit board 16 is located) by folding, thereby forming a "U"-shaped wrapping structure, extending the protection to the side of the battery cell assembly 10, and improving the protective effect of the baffle 17 on the battery cell assembly 10.

[0105] In some embodiments, such as Figure 18 and Figure 19As shown, the baffle 17 may further include a main region 170 and a third region 173 extending outward from the main region 170. One side of the battery cell assembly 10 may be wavy, and the third region 173 may be wavy to match the wavy shape. The main region 170 may be attached to one end face of the battery cell assembly 10, and the third region 173 may be attached to one end face of the battery cell assembly 10 together with the main region 170, with the third region 173 located below the main region 170. In this case, the wavy third region 173 conforms to the non-flat contour of the battery cell assembly 10, filling the curved surface gaps that cannot be tightly covered by the traditional rectangular baffle 17. The wavy extension improves material utilization, thereby reducing wrinkles or gaps in the curved surface area caused by the rigid baffle 17, and ensuring that the baffle 17 does not shift or fall off under vibration.

[0106] Figure 20 This is a schematic diagram of the position of the paper baffle 17 covering the battery cell assembly 10 from another perspective of an embodiment of this application.

[0107] In some embodiments, such as Figure 20 As shown, the cell support 15 has at least one protrusion 153, and the paper stop 17 has a number of notches 1701 that match the protrusion 153 and are adapted to the shape of the protrusion 153. In this case, the notches 1701 of the paper stop 17 are adapted to the shape of the protrusion 153 of the cell support 15, which can achieve mechanical positioning. During assembly, the protrusion 153 is inserted into the notches 1701 of the paper stop 17, which can eliminate the partial exposure of the cell connector 14 caused by the positional offset of the conventional paper stop 17, and at the same time improve the assembly accuracy and efficiency.

[0108] In some embodiments, the baffle 17 is made of a plastic-based material or a hydrophobic material. The baffle 17 body made of a plastic-based / hydrophobic material has a low surface energy characteristic in its molecular structure, which allows liquid water to form a hydrophobic contact angle on the surface and prevent it from wetting. Thus, even in a high-humidity environment, the water will simply roll off and will not adsorb dust. This can physically block the conductive path of "water film + contaminants" in the charged parts, thereby improving the protection effect on the battery cell assembly 10.

[0109] In some embodiments, the paper backing 17 is adhered to the surface of the cell connector 14 by an adhesive backing, which is a plastic-based material or a hydrophobic material. In this case, the hydrophobic adhesive backing can form a non-polar bonding interface between the paper backing 17 and the cell connector 14. Compared with traditional hydrophilic adhesive layers, this interface does not retain water molecules, thereby preventing peeling due to moisture absorption and expansion of the adhesive or the formation of ion migration channels, and maintaining the adhesive seal in long-term humid environments.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A battery pack, comprising a housing, a plurality of battery cells housed in the housing, a battery cell connector mounted on the end of each battery cell, and a circuit board connected to the battery cells, wherein the plurality of battery cells are connected in series and / or in parallel via the battery cell connector; characterized in that, The cell connector has a welding portion mounted on the cell and a connecting portion connected to the circuit board. The plane of the welding portion and the plane of the connecting portion are opposite. The battery pack also includes a baffle connected to the end face of the cell connector. The baffle is attached to at least a portion of the welding portion and the connecting portion.

2. The battery pack according to claim 1, characterized in that, The battery pack also includes a cell support, in which at least one cell is disposed, the cell support having an opening corresponding to the number of cells, the cell being connected to the welded portion of the cell connector via the opening.

3. The battery pack according to claim 2, characterized in that, The cell connector is in the form of a thin sheet. The cell connector also has an intermediate portion connecting the welding portion and the connecting portion. The intermediate portion is disposed in contact with the surface of the cell bracket, and the welding portion and the cell bracket together cover the end of the cell.

4. The battery pack according to claim 2, characterized in that, The battery cell, the battery cell bracket, and the battery cell connector are defined as a battery cell assembly. The circuit board is disposed on the top surface of the main body of the battery cell assembly and configured to control the discharge and / or charging of the battery cell. The battery cell connector is disposed on the side surface of the main body of the battery cell assembly and configured to connect the battery cells in series and parallel. The baffle includes a main body area that at least partially covers the welding portion, and the main body area is attached to the side surface of the main body.

5. The battery pack according to claim 4, characterized in that, The baffle includes a first folded area connected to the main body area, and the first folded area is attached to the top surface of the main body by folding.

6. The battery pack according to claim 4, characterized in that, The paper stop includes a second folded area connected to the main body area, the second folded area being perpendicular to the main body area.

7. The battery pack according to claim 4, characterized in that, The baffle includes a third region extending from the main body region in a direction away from the circuit board, the side of the battery cell assembly is wavy, and the third region is wavy in shape to match the wavy shape.

8. The battery pack according to claim 2, characterized in that, The cell support has at least one protrusion, and the paper baffle has an equal number of openings that are adapted to the shape of the protrusion.

9. The battery pack according to claim 1, characterized in that, The paper barrier is made of plastic or hydrophobic material.

10. The battery pack according to claim 1, characterized in that, The paper backing is attached to the surface of the battery cell connector via adhesive, which is a plastic-based material or a hydrophobic material.

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