Series-connected all-electrode battery pack

Abstract

This utility model discloses a series-connected all-tab battery pack, comprising: two parallel-arranged cells, each cell having a positive conductive portion and a negative conductive portion at both ends; a top cover assembly, which covers one end of the two cells, including a cover plate, a positive electrode post, a positive electrode connecting piece, a negative electrode post, and a negative electrode connecting piece located on the cover plate, the positive electrode post and the positive electrode connecting piece being integrally formed, and the negative electrode post and the negative electrode connecting piece being integrally formed; the positive electrode connecting piece and the negative electrode connecting piece are electrically connected to the corresponding positive and negative conductive portions, respectively; the positive and negative conductive portions of the two cells at the ends opposite to the top cover assembly are electrically connected. This all-tab battery pack avoids the problem of uneven current distribution caused by differences in individual cells in parallel systems, thereby reducing the possibility of local overheating; at the same time, the integrally formed structure of the electrode post and the connecting piece in the top cover assembly eliminates the separate welding process, significantly reducing the internal resistance and interface defect rate of the connection points.

Description

Technical Field

[0001] This utility model relates to the field of battery packaging technology, and in particular to a series-connected all-tab battery pack. Background Technology

[0002] In the field of battery technology, especially in high-energy-density and high-power-density applications, all-tab batteries have attracted widespread attention due to their excellent current conduction performance and structural stability. Existing all-tab battery packs typically employ multiple cells connected in parallel to increase the overall capacity output of the battery pack. However, while increasing capacity, the parallel connection design often leads to an increase in battery pack size and weight, making it difficult to meet the lightweight and compact design requirements of high-energy-density applications (such as electric vehicles and energy storage systems). Furthermore, the multi-cell parallel structure of traditional battery packs requires additional complex electrical connection components, increasing manufacturing costs and assembly complexity.

[0003] In terms of battery pack manufacturing processes, current technologies often employ a separate design for the terminals and connecting pieces of the battery cells, requiring ultrasonic welding and other methods to achieve electrical connections. This process not only increases production steps but may also lead to increased internal resistance of the battery pack due to increased contact resistance at the welding interface, affecting energy transfer efficiency. Furthermore, instability in welding quality can cause risks of incomplete connections or breakage, reducing the long-term reliability of the battery pack. Especially under high-current operating conditions, the temperature rise at the welding points may further exacerbate energy loss and even pose safety hazards. Utility Model Content

[0004] The purpose of this invention is to provide a series-connected all-tab battery pack that simplifies the assembly process and improves electrical and safety performance.

[0005] To achieve the above objectives, this utility model provides a series-connected omni-tab battery pack, comprising: Two parallel battery cells, each of which has a positive conductive portion formed based on a positive electrode blank portion and a negative conductive portion formed based on a negative electrode blank portion at both ends, wherein the positive conductive portion of one battery cell and the negative conductive portion of the other battery cell are located at the same end; A top cover assembly, which covers one end of the two battery cells, includes a cover plate, a positive terminal, a positive connecting piece, a negative terminal, and a negative connecting piece located on the cover plate. The positive terminal and the positive connecting piece are integrally formed, and the negative terminal and the negative connecting piece are integrally formed. The positive and negative terminals are used for electrical connection with a load, and the positive and negative connecting pieces are respectively electrically connected to the corresponding positive and negative conductive parts. The positive and negative conductive parts of the two battery cells at the ends opposite to the top cover assembly are electrically connected.

[0006] Preferably, the positive conductive portion and the negative conductive portion are elongated.

[0007] Preferably, the positive electrode connector includes a first portion directly opposite the positive electrode post and a second portion offset from the positive electrode post, the second portion being attached to the positive conductive portion; the negative electrode connector includes a third portion directly opposite the negative electrode post and a fourth portion offset from the negative electrode post, the fourth portion being attached to the negative conductive portion; the size of the second portion is equivalent to that of the positive conductive portion, and the size of the fourth portion is equivalent to that of the negative conductive portion.

[0008] Preferably, it also includes a housing in which the two said battery cells are housed, and the cover plate is sealed to the opening of the housing.

[0009] Preferably, the cover plate is provided with a first through hole and a second through hole, the positive electrode post is embedded in the first through hole, the negative electrode post is embedded in the second through hole, a first sealing ring is also provided in the first through hole, and a second sealing ring is also provided in the second through hole.

[0010] Preferably, the cover plate is also provided with an explosion-proof valve. When the air pressure inside the cover plate exceeds a preset value, the explosion-proof valve is opened to release the gas inside the housing.

[0011] Preferably, the positive conductive portion and the negative conductive portion of the two battery cells at the opposite end of the top cover assembly are ultrasonically welded, and an auxiliary connecting plate with conductive properties is provided on the inner side of the connection between the positive conductive portion and the negative conductive portion to be welded.

[0012] Preferably, an insulating fixing plate is also provided between the auxiliary connecting plate and the outer surfaces of the two battery cells.

[0013] Compared with existing technologies, the series-connected all-tab battery pack provided by the above technical solution achieves voltage superposition through the series design of two cells, reducing the redundant connection space required for parallel connection. In addition, in the series structure, the current paths of the two cells are symmetrical and consistent, avoiding the problem of uneven current distribution caused by individual cell differences in parallel systems, thereby reducing the possibility of local overheating. At the same time, the integrated molding structure of the positive electrode post and positive electrode connecting piece and the negative electrode post and negative electrode connecting piece in the top cover assembly eliminates the separate welding process, significantly reducing the internal resistance and interface defect rate of the connection parts, thereby improving the electrochemical stability and production consistency of the battery pack. It can be seen that this battery pack effectively solves the technical bottlenecks of complex battery pack structure, limited energy density and high manufacturing cost in existing technologies, providing a new technical path for the development of high-power battery systems. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the all-tab battery pack in an embodiment of this utility model.

[0015] Figure 2 This is an exploded view of the cover plate assembly and the battery cell in an embodiment of this utility model.

[0016] Figure 3 This is an internal structural diagram of the cover plate assembly in an embodiment of this utility model.

[0017] Figure 4 This is an exploded view of the cover plate assembly in an embodiment of this utility model.

[0018] Figure 5 This is a three-dimensional structural diagram of the all-tab battery pack in an embodiment of this utility model from another perspective. Detailed Implementation

[0019] To explain in detail the technical content, structural features, objectives and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0020] This embodiment discloses a series-connected all-tab battery pack, such as Figures 1 to 5 It includes two parallel battery cells 1 and a top cover assembly 2.

[0021] Each battery cell 1 has a positive conductive portion 10 formed based on the positive electrode blank portion and a negative conductive portion 11 formed based on the negative electrode blank portion at both ends, wherein the positive conductive portion 10 of one battery cell 1 and the negative conductive portion 11 of another battery cell 1 are located at the same end.

[0022] A top cover assembly 2 is installed over one end of the two battery cells 1. The top cover assembly 2 includes a cover plate 20, a positive electrode post 21, a positive electrode connecting piece 22, a negative electrode post 23, and a negative electrode connecting piece 24 located on the cover plate 20. The positive electrode post 21 and the positive electrode connecting piece 22 are integrally formed, and the negative electrode post 23 and the negative electrode connecting piece 24 are integrally formed. The positive electrode post 21 and the negative electrode post 23 are used for electrical connection with the load, and the positive electrode connecting piece 22 and the negative electrode connecting piece 24 are respectively electrically connected to the corresponding positive electrode conductive part 10 and negative electrode conductive part 11. The positive electrode conductive part 10 and the negative electrode conductive part 11 at the end of the two battery cells 1 opposite to the top cover assembly 2 are electrically connected (e.g., Figure 5 ).

[0023] The series-connected all-tab battery pack provided by the above technical solution achieves voltage superposition through the series connection of two cells 1, reducing the redundant connection space required for parallel connection. Furthermore, in the series structure, the current paths of the two cells 1 are symmetrical and consistent, avoiding uneven current distribution caused by differences in individual cells in parallel systems, thereby reducing the possibility of localized overheating. Simultaneously, the integrated molding structure of the positive electrode post 21 and positive electrode connecting piece 22, and the negative electrode post 23 and negative electrode connecting piece 24 in the top cover assembly 2 eliminates the need for separate welding processes, significantly reducing the internal resistance and interface defect rate at the connection points, thereby improving the electrochemical stability and production consistency of the battery pack. Therefore, this battery pack effectively solves the technical bottlenecks of complex battery pack structure, limited energy density, and high manufacturing cost in existing technologies, providing a new technical path for the development of high-power battery systems.

[0024] In summary, this technical solution systematically addresses the pain points of traditional parallel battery packs, such as volume redundancy, complex manufacturing processes, and insufficient reliability, through series topology reconstruction, integrated terminal block design, and full tab conductivity optimization. It provides a more competitive battery pack solution for high power density applications.

[0025] The integrated molding process of the positive electrode post 21, positive electrode connector 22, negative electrode post 23, and negative electrode connector 24 can be achieved using various metal forming technologies such as casting, stamping, and extrusion to optimize production efficiency and cost. In some scenarios requiring higher power output, multiple series-connected battery packs can be further connected in parallel to form a hybrid series-parallel battery system to meet more complex application needs.

[0026] On the other hand, the positive electrode conductive part 10 and the negative electrode conductive part 11 are elongated.

[0027] This design allows the positive conductive portion 10 and the negative conductive portion 11 to extend along the length of the cell 1, providing a longer connection path and a larger contact area. The elongated positive conductive portion 10 and the negative conductive portion 11 are typically the same length as the cell 1, but relatively narrow in width, to ensure effective connection with the electrode material and current extraction. This shape is designed to optimize the current transmission path within the cell 1 and reduce resistance loss. The elongated conductive portion is usually formed by leaving uncoated areas (blank areas) on the current collector during the cell 1 manufacturing process. The material is the same as the current collector, typically copper foil (negative electrode) and aluminum foil (positive electrode).

[0028] Furthermore, the shape of the positive electrode conductive part 10 and the negative electrode conductive part 11 also provides a larger operating window and a more stable connection point when subsequently welded or connected to the positive electrode connecting piece 22 and the negative electrode connecting piece 24, further improving the reliability of the battery pack.

[0029] Furthermore, the positive electrode connector 22 includes a first portion 22a directly opposite to the positive electrode post 21 and a second portion 22b offset from the positive electrode post 21. The second portion 22b is attached to the positive electrode conductive portion 10. The negative electrode connector 24 includes a third portion 24a directly opposite to the negative electrode post 23 and a fourth portion 24b offset from the negative electrode post 23. The fourth portion 24b is attached to the negative electrode conductive portion 11. The size of the second portion 22b is equivalent to that of the positive electrode conductive portion 10, and the size of the fourth portion 24b is equivalent to that of the negative electrode conductive portion 11.

[0030] In this embodiment, the positive electrode connector 22 includes a first portion 22a directly opposite to the positive electrode post 21 and a second portion 22b offset from the positive electrode post 21. The first portion 22a mainly serves as a transition region for current from the positive electrode post 21 to the second portion 22b, while the second portion 22b is directly attached to the positive electrode conductive part 10 and is responsible for electrical connection with the battery cell 1. Similarly, the negative electrode connector 24 includes a third portion 24a directly opposite to the negative electrode post 23 and a fourth portion 24b offset from the negative electrode post 23. The third portion 24a is a transition region for current from the negative electrode post 23 to the fourth portion 24b, while the fourth portion 24b is attached to the negative electrode conductive part 11.

[0031] The dimensions of the second part 22b are equivalent to those of the positive conductive portion 10, and the dimensions of the fourth part 24b are equivalent to those of the negative conductive portion 11. This means that the contact area between the positive connecting piece 22 and the positive conductive portion 10, and between the negative connecting piece 24 and the negative conductive portion 11, is maximized, thereby ensuring a low-resistance connection. These connecting pieces are typically made of highly conductive metal materials (such as copper, aluminum, or their alloys) by stamping or integral molding to ensure efficient current transmission.

[0032] In the above embodiments, the attachment methods of the second part 22b and the fourth part 24b can employ various technologies, such as ultrasonic welding, laser welding, resistance welding, or mechanical pressing, to adapt to the requirements of different materials and production costs.

[0033] To further optimize contact performance, special treatments, such as tin plating, nickel plating, or microstructuring, can be applied to the surfaces of the second part 22b and the fourth part 24b to improve conductivity and oxidation resistance. The dimensions of the second part 22b and the fourth part 24b are "comparable," which can be defined as a range; for example, their length and width can be between 90% and 110% of the corresponding dimensions of the positive conductive portion 10 and the negative conductive portion 11, to allow for certain manufacturing tolerances while ensuring sufficient contact area.

[0034] On the other hand, the two battery cells 1 are housed in a housing 3, and the cover plate 20 is sealed to the opening of the housing 3.

[0035] This embodiment significantly improves the protection level of the battery pack by introducing a housing 3 and achieving a sealed connection between the cover plate 20 and the housing 3. This enables the battery pack to effectively resist adverse environmental factors such as external mechanical shock, vibration, moisture, and dust, thereby extending the battery pack's service life. The housing 3 also provides robust support for the overall structure of the battery pack, facilitating installation and integration into various devices.

[0036] In the above embodiments, the material of the housing 3 can be selected according to the application scenario and cost requirements. For example, for applications with high lightweight requirements, carbon fiber composite materials can be used; for applications with high heat dissipation requirements, aluminum alloys with higher thermal conductivity can be used. Additional cushioning materials (such as foam materials or rubber pads) or shock-absorbing structures can be installed inside the housing 3 to further enhance its impact and vibration resistance. The sealing method between the cover plate 20 and the housing 3 can be replaced with various solutions. For example, in addition to gaskets and sealants, hot-melt welding, laser welding, or ultrasonic welding can be used to achieve a more permanent and reliable seal. To facilitate battery pack maintenance and recycling, the housing 3 can be designed as a detachable structure, for example, through modular design or reusable fasteners.

[0037] Furthermore, the cover plate 20 is provided with a first through hole 25 and a second through hole 26. The positive electrode post 21 is embedded in the first through hole 25, and the negative electrode post 23 is embedded in the second through hole 26. A first sealing ring 27 is also provided in the first through hole 25, and a second sealing ring 28 is also provided in the second through hole 26.

[0038] By setting a first sealing ring 27 and a second sealing ring 28 in the first through hole 25 and the second through hole 26 respectively, the sealing performance of the battery pack is significantly improved, effectively preventing external contaminants such as moisture and dust from entering the battery, thereby avoiding short circuits and corrosion, and improving the long-term reliability and safety of the battery. This solution also prevents leakage of electrolyte or gas inside the battery, protecting the operating environment and the safety of operators.

[0039] On the other hand, an explosion-proof valve 29 is also provided on the cover plate 20. When the air pressure inside the cover plate 20 exceeds the preset value, the explosion-proof valve 29 is opened to release the gas inside the housing 3.

[0040] During the use of batteries, especially lithium-ion batteries, gas may be generated inside the battery due to overcharging, over-discharging, short circuits, external heating, or internal defects, leading to increased internal pressure. If the internal pressure is too high, it may cause the battery casing to deform or rupture, or even explode, causing serious safety accidents.

[0041] To address this safety hazard, this embodiment incorporates an explosion-proof valve 29 on the cover plate 20. This valve 29 serves as a final safety barrier against internal battery pressure. Its operating principle is that when the internal gas pressure of the battery (i.e., the gas pressure inside the cover plate 20) exceeds a preset safety value, the explosion-proof valve 29 is automatically or passively opened, rapidly releasing the excessive gas pressure within the casing 3 and preventing battery rupture or explosion. This design significantly enhances the inherent safety of the battery pack, effectively preventing thermal runaway and explosion risks, and protecting the safety of users and equipment.

[0042] The explosion-proof valve 29 is a mechanical safety device whose internal structure typically includes a diaphragm, spring, or deformable component with a preset rupture pressure. When gas generated inside the battery causes the pressure inside the cover plate 20 to gradually increase and reach the preset opening pressure of the explosion-proof valve 29, the valve structure deforms or ruptures, thereby forming a pressure relief channel that allows excess gas inside the battery to be quickly discharged outside the housing 3. This passive safety mechanism does not rely on an electronic control system and therefore can operate reliably even under extreme failure conditions.

[0043] On the other hand, the positive conductive part 10 and the negative conductive part 11 at the opposite end of the two battery cells 1 and the top cover assembly 2 are ultrasonically welded together, and an auxiliary connecting plate 40 with conductive properties is provided on the inner side of the connection between the positive conductive part 10 and the negative conductive part 11 to be welded.

[0044] The principle of the auxiliary connecting plate 40 is to provide an additional conductive path and a larger contact area in the welding area. When current passes through the welding point, the auxiliary connecting plate 40 can share part of the current, thereby reducing the local current density, reducing heat generation, and further reducing the overall connection resistance, ensuring the high efficiency, stability and reliability of the series connection between the cells 1.

[0045] Furthermore, an insulating fixing plate 41 is also provided between the auxiliary connecting plate 40 and the outer surface of the two battery cells 1.

[0046] The fixing plate 41 is typically made of a material with good insulation properties and a certain mechanical strength, such as polypropylene (PP), polycarbonate (PC), epoxy resin board, or ceramic material. The shape and size of the fixing plate 41 are designed for precise insertion or snapping into the gap between the auxiliary connecting plate 40 and the outer wall of the cell 1, forming a tight fit. The fixing plate 41 is used to firmly fix the auxiliary connecting plate 40 in a predetermined position, preventing its displacement when the battery pack is subjected to vibration, impact, or temperature changes. At the same time, the insulation properties of the fixing plate 41 ensure that there is no electrical contact between the auxiliary connecting plate 40 and the outer wall of the cell 1 (usually the battery casing 3 or encapsulation material), thereby eliminating the risk of short circuit.

[0047] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the scope of the present utility model application shall still fall within the scope of the present utility model.

Claims

1. A series connected full tab battery characterized in that, include: Two parallel battery cells, each of which has a positive conductive portion formed based on a positive electrode blank portion and a negative conductive portion formed based on a negative electrode blank portion at both ends, wherein the positive conductive portion of one battery cell and the negative conductive portion of the other battery cell are located at the same end; A top cover assembly is disposed over one end of the two battery cells. The top cover assembly includes a cover plate, a positive terminal, a positive connecting piece, a negative terminal, and a negative connecting piece located on the cover plate. The positive terminal and the positive connecting piece are integrally formed, and the negative terminal and the negative connecting piece are integrally formed. The positive terminal and the negative terminal are used for electrical connection with a load. The positive connecting piece and the negative connecting piece are respectively electrically connected to the corresponding positive conductive part and negative conductive part. The positive conductive parts and negative conductive parts of the two battery cells at the ends opposite to the top cover assembly are electrically connected.

2. The series connected full tabbed battery pack of claim 1, wherein, The positive conductive part and the negative conductive part are elongated strips.

3. The series connected full tabbed battery of claim 2, wherein, The positive electrode connector includes a first portion directly opposite the positive electrode post and a second portion offset from the positive electrode post. The second portion is attached to the positive conductive portion. The negative electrode connector includes a third portion directly opposite the negative electrode post and a fourth portion offset from the negative electrode post. The fourth portion is attached to the negative conductive portion. The size of the second portion is equivalent to that of the positive conductive portion, and the size of the fourth portion is equivalent to that of the negative conductive portion.

4. The series-connected full-tab battery pack of claim 1, wherein, It also includes a housing in which the two said battery cells are housed, and the cover plate is sealed to the opening of the housing.

5. The series connected full tabbed battery of claim 4, wherein, The cover plate is provided with a first through hole and a second through hole. The positive electrode post is embedded in the first through hole and the negative electrode post is embedded in the second through hole. A first sealing ring is also provided in the first through hole and a second sealing ring is also provided in the second through hole.

6. The series-connected full-tab battery pack of claim 4, wherein, The cover plate is also equipped with an explosion-proof valve. When the air pressure inside the cover plate exceeds a preset value, the explosion-proof valve is opened to release the gas inside the housing.

7. The series-connected full-tab battery of claim 1, wherein, The positive and negative conductive parts of the two battery cells at the opposite end of the top cover assembly are ultrasonically welded together, and an auxiliary connecting plate with conductive properties is provided on the inner side of the connection between the positive and negative conductive parts to be welded.

8. The series-connected full-tab battery pack of claim 7, wherein, An insulating fixing plate is also provided between the auxiliary connecting plate and the outer surfaces of the two battery cells.

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