Automobile battery pack, automobile and packaging method of automobile battery pack

Abstract

The present application relates to the technical field of lithium battery, especially to a car battery pack, a car and a packaging method of the car battery pack, the car battery pack provided by the present application comprises a bottom cover, a top cover and a battery module, a battery compartment is formed between the bottom cover and the top cover, and a plurality of pressure relief holes are formed in the bottom cover; the battery module is arranged in the battery compartment, the battery module comprises a plurality of battery cells, one end of the plurality of battery cells towards the bottom cover is provided with a pressure relief structure, and the plurality of pressure relief structures are respectively arranged corresponding to the plurality of pressure relief holes. The car battery pack provided by the present application can provide a direct, fast and efficient pressure release channel for each battery cell, realize timely response and effective protection of the abnormal battery cell, and ensure that the battery pack can maintain good safety performance when facing single or multiple abnormal battery cells.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and more particularly to an automotive battery pack, an automobile, and a method for packaging the automotive battery pack. Background Technology

[0002] With the rapid development of the new energy vehicle industry, power battery technology has become a key factor determining vehicle performance and safety. Existing automotive battery packs typically consist of multiple cells that can stably undergo charge-discharge cycles under normal operating conditions, providing a reliable power source for the vehicle.

[0003] However, in actual use, the battery cell may react abnormally due to overcharging, over-discharging, internal short circuits, external impacts, or thermal abuse, resulting in the generation of a large amount of gas inside and a sharp increase in internal pressure. These gases mainly include hydrogen, carbon monoxide, and various organic gases produced by the decomposition of the electrolyte. When the pressure exceeds the cell's tolerance, it may cause the cell to expand, deform, or even burst, leading to thermal runaway.

[0004] To address the aforementioned safety risks, various battery pack pressure relief technologies have emerged in the existing field. For example, some battery pack designs incorporate a uniform pressure relief valve on the side wall or top, which opens to release pressure when the internal pressure exceeds a set value. Other solutions involve creating venting channels at specific locations within the battery pack, relying on pressure differences to drive gas outwards. Additionally, some technologies incorporate pressure relief diaphragms on the battery cells; these diaphragms rupture and release gas when overpressure occurs inside the cell.

[0005] However, existing pressure relief technologies still have significant technical shortcomings in practical applications. First, the response mechanism of a unified pressure relief valve relies on the accumulation of pressure throughout the entire battery pack. When a single cell malfunctions, the generated gas needs to diffuse within the battery pack and reach sufficient pressure before triggering the pressure relief valve. This process involves a significant time delay, making it impossible to respond promptly to cell malfunctions. Second, existing venting channel designs are typically complex, requiring gas to pass through multiple turns and transitions within the battery pack before reaching the vent. This indirect venting method not only prolongs the pressure relief time but may also cause high-temperature, high-pressure gas to remain within the pack, causing thermal shock to other normal cells and triggering a chain reaction of failures. Simultaneously, due to the lack of a dedicated gas venting channel, the high-temperature gas generated during pressure relief can easily affect other components within the battery pack, including corroding wiring, damaging sensors, or interfering with the normal operation of other cells. This leads to a continuous accumulation of pressure within the battery pack, potentially resulting in more serious safety accidents. Summary of the Invention

[0006] This invention provides an automotive battery pack that provides a direct, fast, and efficient pressure release channel for each cell, enabling timely response and effective protection against cell anomalies, and ensuring that the battery pack maintains good safety performance when faced with single or multiple cell anomalies.

[0007] The present invention provides an automotive battery pack, comprising: a bottom cover and a top cover, wherein a battery compartment is formed between the bottom cover and the top cover, and a plurality of pressure relief holes are provided on the bottom cover; a battery module is disposed in the battery compartment, the battery module comprising a plurality of battery cells, and a pressure relief structure is provided at one end of the plurality of battery cells facing the bottom cover, and the plurality of pressure relief structures are respectively provided with the plurality of pressure relief holes.

[0008] In one possible implementation, the pressure relief structure can form a pressure relief channel after rupture, and the pressure relief channel is connected to the pressure relief hole.

[0009] In one possible implementation, the inner diameter of the pressure relief orifice is larger than the diameter of the pressure relief channel.

[0010] In one possible implementation, the pressure relief structure and the pressure relief hole are arranged concentrically.

[0011] In one possible implementation, the pressure relief structure is located in the central region of the positive electrode of the cell.

[0012] In one possible implementation, the pressure relief structure has a preset groove. When the internal air pressure of the battery cell reaches the rupture pressure threshold, the pressure relief structure ruptures along the preset groove.

[0013] In one possible implementation, the pressure relief structure adopts an aluminum film and butyl rubber composite layer structure, with a burst pressure threshold of 0.8-1.3 MPa.

[0014] In one possible implementation, the battery module also includes a current-carrying plate, which is welded to the terminal block of the battery cell; a boss is provided on the inner surface of the bottom cover, which abuts against the welding part of the current-carrying plate and the terminal block.

[0015] In one possible implementation, the boss is a ring-shaped structure arranged around the pressure relief hole.

[0016] In one possible implementation, a positioning structure for positioning the battery cell is provided inside the top cover.

[0017] In a second aspect, the present invention provides an automobile, comprising: a vehicle body; and the aforementioned automobile battery pack, wherein the automobile battery pack is disposed on the vehicle body, and the bottom cover of the automobile battery pack constitutes at least a portion of the automobile chassis.

[0018] Thirdly, the present invention provides a method for packaging the above-mentioned automotive battery pack, comprising the following steps: positioning the battery cells of the battery module inside the top cover; performing busbar welding and acquisition line welding to electrically connect multiple battery cells; assembling the bottom cover and the top cover and pressing the battery module together to form a battery pack; flipping the battery pack over so that the top cover faces upwards; and injecting sealant into the gap between the top cover and the bottom cover.

[0019] The automotive battery pack provided by this invention features a corresponding vent hole for each battery cell on the battery pack cover. When a cell experiences internal overpressure due to an abnormality, the high-temperature, high-pressure gas generated by the pressure relief structure can be directly discharged through the corresponding vent hole, eliminating the need for diffusion and accumulation within the battery pack. This reduces the pressure relief response time from several seconds in existing technologies to milliseconds. This point-to-point venting method ensures that the pressure relief processes of multiple cells simultaneously malfunction without interference, avoiding the problem of poor venting due to excessive load on a single pressure relief channel. Furthermore, the gas generated by the malfunctioning cell is directly discharged outside the pack, preventing thermal shock and chemical corrosion to adjacent cells and effectively blocking the propagation path of thermal runaway between cells. The uniform distribution of vent holes also optimizes the pressure distribution of the battery pack, avoiding localized pressure concentration caused by a single vent location, improving the structural stability of the battery pack. Each vent hole has a clearly defined function, facilitating fault location and maintenance inspection. It provides a direct, fast, and efficient pressure release channel for each cell, enabling timely response and effective protection against cell malfunctions, ensuring the battery pack maintains good safety performance even when facing single or multiple cell malfunctions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is an exploded structural diagram of an automotive battery pack provided by the present invention; Figure 2 This is a three-dimensional structural diagram of a bottom cover provided by the present invention; Figure 3 This is a three-dimensional structural diagram of a bottom cover provided by the present invention from another perspective; Figure 4 yes Figure 3 A magnified schematic diagram of the structure at point A; Figure 5 This is a three-dimensional structural diagram of a top cover provided by the present invention; Figure 6 This is a schematic diagram of the structure of a battery cell provided by the present invention; Figure 7 This is a flowchart of an automotive battery pack packaging method provided by the present invention.

[0022] Figure label: 1. Bottom cover; 11. Pressure relief hole; 12. Boss; 2. Top cover; 21. Positioning structure; 3. Battery module; 31. Battery cell; 311. Pressure relief structure; 3111. Preset groove; 312. Terminal post. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] The following is combined with Figures 1 to 6 The present invention describes an automotive battery pack, comprising: a bottom cover 1, a top cover 2, and a battery module 3, wherein: A battery compartment is formed between the bottom cover 1 and the top cover 2, and multiple pressure relief holes 11 are provided on the bottom cover 1.

[0025] The battery module 3 is located inside the battery compartment. The battery module 3 includes multiple battery cells 31. Each of the multiple battery cells 31 has a pressure relief structure 311 at one end facing the bottom cover 1. The multiple pressure relief structures 311 and multiple pressure relief holes 11 are respectively provided.

[0026] In this invention, by providing a corresponding vent hole for each cell 31 on the battery pack cover, when a cell 31 experiences internal overpressure due to an abnormality, the high-temperature and high-pressure gas generated by the pressure relief structure 311 can be directly discharged to the outside through the corresponding vent hole, without needing to diffuse and accumulate inside the battery pack. This reduces the pressure relief response time from several seconds in the prior art to the millisecond level. This point-to-point venting method ensures that the pressure relief processes of multiple cells 31 do not interfere with each other when multiple cells 31 malfunction simultaneously, avoiding the problem of poor venting due to excessive load on a single pressure relief channel. Simultaneously, the gas generated by the malfunctioning cell 31 is directly discharged outside the pack, preventing thermal shock and chemical corrosion to adjacent cells 31, effectively blocking the propagation path of thermal runaway between cells 31. The uniform distribution of the vent holes also optimizes the pressure distribution of the battery pack, avoiding local pressure concentration caused by a single vent location, improving the structural stability of the battery pack. Furthermore, each vent hole has a clearly defined function, facilitating fault location and maintenance inspection. It can provide a direct, fast, and efficient pressure release channel for each cell 31, enabling timely response and effective protection against cell 31 anomalies, and ensuring that the battery pack can maintain good safety performance when faced with anomalies in one or more cells 31.

[0027] Specifically, when a short circuit occurs inside cell 31, a large amount of gas is rapidly generated, mainly consisting of hydrogen, carbon monoxide, and electrolyte decomposition products. This rapid increase in gas leads to a rapid rise in internal pressure within cell 31. The pressure relief structure 311 ruptures when the pressure reaches a preset threshold, providing an outlet for the high-pressure gas. The corresponding pressure relief hole 11 provides a clear channel for the gas to exit the battery pack, and the entire process is completed automatically without external intervention. When a cell 31 in the battery pack experiences thermal runaway, the pressure relief structure 311 of that cell 31 ruptures, allowing the internal high-pressure gas to be directly discharged to the bottom of the vehicle through the corresponding pressure relief hole 11 on the bottom cover 1. This does not interfere with the working environment of other cells 31 in the battery compartment, enabling the remaining cells 31 to continue operating normally and ensuring the vehicle has sufficient range to escape dangerous areas.

[0028] In related technologies, battery pack depressurization typically relies on a unified depressurization valve or a side venting structure. When a cell 31 malfunctions, the generated gas needs to travel through a complex path inside the battery compartment to be discharged. This indirect venting method not only prolongs the depressurization time but may also cause high-temperature gas to remain inside the battery compartment, causing thermal shock to other normal cells 31. In this invention, the depressurization structure 311 of each cell 31 corresponds one-to-one with the depressurization hole 11 on the bottom cover 1, constructing the shortest and most direct gas discharge path. High-pressure gas can be discharged quickly and efficiently from the bottom of the vehicle, avoiding secondary heat and pressure transfer inside the battery compartment and effectively curbing the spread of thermal runaway to surrounding cells 31.

[0029] In some embodiments, the pressure relief structure 311 may form a pressure relief channel after rupture, and the pressure relief channel is connected to the pressure relief hole 11.

[0030] In this invention, the pressure relief structure 311 forms a pressure relief channel after rupture and is connected to the pressure relief hole 11 on the bottom cover 1, establishing a complete gas emission path from the inside of the cell 31 to the outside of the battery pack. This eliminates flow blockage during gas emission, ensures the continuity and effectiveness of pressure release, and avoids repeated pressure accumulation caused by obstructed channels.

[0031] Specifically, the pressure relief channel formed by the rupture of the pressure relief structure 311 has a specific geometry and flow cross-section. When the internal high-pressure gas flows through this channel to the pressure relief hole 11, the connection between the two ensures a smooth airflow transition, preventing flow separation or eddy currents at the connection point and maximizing gas emission efficiency. The direct connection between the pressure relief channel and the pressure relief hole 11 eliminates all discontinuities in the gas emission path, forming a continuous exhaust channel. This ensures smooth gas flow from inside the cell 31 to the outside of the battery pack, significantly improving the response speed and exhaust efficiency of the pressure relief system.

[0032] In some embodiments, the inner diameter of the pressure relief hole 11 is larger than the diameter of the pressure relief channel.

[0033] In this invention, the inner diameter of the pressure relief hole 11 is larger than the diameter of the pressure relief channel, providing sufficient flow space for the discharge of high-pressure gas, avoiding the exhaust hole diameter from becoming a limiting factor for gas flow, eliminating the flow contraction that may occur when gas enters the pressure relief hole 11 from the pressure relief channel, reducing pressure loss, and improving the working efficiency of the entire pressure relief system.

[0034] Specifically, when high-pressure gas enters the larger-diameter pressure relief hole 11 from the relatively small pressure relief channel, the sudden increase in the flow cross-sectional area leads to a decrease in gas velocity and pressure, which is beneficial for the continuous discharge of gas from inside the battery cell 31 to the external environment. At the same time, the larger inner diameter of the pressure relief hole 11 also provides sufficient margin for tolerance variations during manufacturing and assembly processes.

[0035] In one specific embodiment, the inner diameter of the pressure relief hole 11 is set to be greater than 15mm, while the diameter of the pressure relief channel is usually in the range of 8-12mm. This ensures that even in the extreme case where multiple cells 31 are depressurized at the same time, there will be no exhaust interference due to insufficient exhaust hole diameter, thus ensuring that each pressure relief channel can obtain sufficient exhaust capacity.

[0036] In some embodiments, the pressure relief structure 311 and the pressure relief hole 11 are arranged concentrically.

[0037] In this invention, the pressure relief structure 311 and the pressure relief hole 11 are concentrically arranged, which realizes the geometric optimization of the gas emission path and eliminates the airflow deflection and energy loss that may be caused by the eccentric arrangement. The concentric arrangement allows the high-pressure gas discharged from the pressure relief structure 311 to directly enter the pressure relief hole 11 along the shortest path, maximizing the directionality and efficiency of gas emission.

[0038] Specifically, the concentric arrangement means that the central axis of the pressure relief structure 311 is completely coincident with the central axis of the pressure relief hole 11. When gas flows out from the opening formed after the pressure relief structure 311 ruptures, its mainstream direction is consistent with the axis of the pressure relief hole 11, avoiding sudden changes in the gas flow direction and reducing flow resistance and turbulence losses. This axial alignment also ensures that the gas impact force is transmitted along a predetermined direction and does not generate lateral loads on other parts of the battery pack.

[0039] In a specific embodiment, the concentricity of the pressure relief structure 311 and the pressure relief hole 11 is controlled within 0.05 mm. When the cell 31 is depressurized, the high-pressure gas is discharged through the pressure relief hole 11 in an approximately laminar flow manner, which avoids the scouring and wear of the pressure relief hole 11 wall by the gas in the turbulent state and maintains the long-term stability of the pressure relief channel.

[0040] Because multiple battery cells 31 are arranged in an array inside the battery compartment, and the pressure relief structures 311 of the multiple battery cells 31 correspond to multiple pressure relief holes 11 on the bottom shell, if one of the battery cells 31 does not have a concentricity deviation with the pressure relief hole 11, the deviation value will become larger and larger through accumulation. This invention avoids the situation of insufficient pressure relief caused by the accumulation of such deviations by precisely controlling the concentricity of the pressure relief structure 311 of each battery cell 31 with the pressure relief hole 11.

[0041] like Figure 6 As shown, in some embodiments, the pressure relief structure 311 is disposed in the central region of the positive electrode of the cell 31.

[0042] In this invention, the pressure relief structure 311 is set in the central region of the positive electrode of the battery cell 31, which makes full use of the spatial distribution characteristics of the electrochemical reaction inside the battery cell 31. The pressure release outlet is set at the position where gas generation is most concentrated and pressure rises the fastest, which realizes the fastest pressure response and the shortest gas transmission path, and provides the most timely protection for the safety of the battery cell 31.

[0043] Specifically, when an abnormal situation such as an internal short circuit or overcharging occurs in the battery cell 31, the positive electrode material is usually the first part to undergo a decomposition reaction, and a large amount of gas is rapidly generated in the positive electrode area, causing a sharp increase in local pressure. Placing the pressure relief structure 311 in the central region of the positive electrode can directly sense this pressure change without waiting for the gas to diffuse and reach equilibrium throughout the battery cell 31, thus significantly shortening the response time from the occurrence of the abnormality to the initiation of pressure relief.

[0044] In one specific embodiment, when the positive electrode material of the battery cell 31 begins to decompose due to overheating, the generated gas can directly act on the pressure relief structure 311 located at the center of the positive electrode, causing it to rupture immediately when the pressure reaches a dangerous level. This avoids more serious consequences that might result from continued pressure buildup inside the battery cell 31, such as deformation or rupture of the battery cell casing. By placing the pressure relief structure 311 in the central region of the positive electrode, direct monitoring and immediate response to abnormal reactions inside the battery cell 31 are achieved. This provides protection as soon as problems occur inside the battery cell 31, preventing small problems from escalating into major accidents and significantly improving the overall safety level of the battery system.

[0045] like Figure 6 As shown, in some embodiments, the pressure relief structure 311 is provided with a preset groove 3111. When the internal air pressure of the battery cell 31 reaches the rupture pressure threshold, the pressure relief structure 311 ruptures along the preset groove 3111.

[0046] In this invention, by setting a preset notch 3111 on the pressure relief structure 311, the pressure relief process is controlled and managed, ensuring that the pressure relief structure 311 can rupture in a predetermined manner and at a predetermined time. The preset notch 3111, as a manually designed weak point, not only controls the initiation position of the rupture but also guides the direction of rupture propagation, avoiding the uncertainty and potential risks that may be caused by random rupture.

[0047] Specifically, the pre-cut notches 3111 are precision-machined to form grooves with strictly controlled depth and width on the surface of the pressure relief structure 311. The material thickness of these grooved areas is reduced, making them the areas with the highest stress concentration coefficient in the entire pressure relief structure 311. When the internal gas pressure of the battery cell 31 reaches the rupture pressure threshold, the stress first reaches the yield strength of the material at the notches, triggering the initial rupture. Subsequently, the crack steadily propagates along the notch path, forming a pressure relief opening with a regular shape and controllable size.

[0048] The pre-set notch 3111 guides the pressure relief, ensuring that each pressure relief produces the expected rupture effect. The location, size, and shape of the rupture are all within the design control range, which not only guarantees the consistency of pressure relief performance but also facilitates post-pressure relief condition assessment and maintenance, thereby improving the reliability of the entire safety system.

[0049] In some embodiments, the pressure relief structure 311 adopts an aluminum film and butyl rubber composite layer structure, with a rupture pressure threshold of 0.8-1.3 MPa.

[0050] In this invention, the pressure relief structure 311 adopts a composite structure of aluminum film and butyl rubber, which fully utilizes the performance advantages of different materials and achieves the best combination of sealing performance and controllable rupture performance. The aluminum film provides excellent gas barrier capability and basic mechanical strength, while the butyl rubber layer contributes good flexibility and chemical stability. The composite structure with the synergistic effect of the two exhibits precise pressure response characteristics in the rupture pressure threshold range of 0.8-1.3 MPa.

[0051] Specifically, the aluminum thin film layer has a dense metallic crystal structure, which can effectively prevent the penetration of electrolyte volatiles and small molecule gases generated by the reaction, maintaining the stability of the internal environment of the cell 31 under normal operating conditions. The butyl rubber layer, as an elastic material, can withstand the thermal stress caused by temperature changes and the small pressure fluctuations during the operation of the cell 31. At the same time, its excellent chemical corrosion resistance ensures long-term stability in the electrolyte environment.

[0052] In some embodiments, the battery module 3 further includes a current-carrying sheet (not shown), which is welded to the terminal post 312 of the cell 31; a boss 12 is provided on the inner surface of the bottom cover 1, which abuts against the welding part of the current-carrying sheet and the terminal post 312.

[0053] In this invention, by providing a boss 12 on the inner surface of the bottom cover 1, which forms an abutment relationship with the welding part of the current carrier plate and the electrode post 312, additional mechanical support is provided for the electrical connection point, which effectively improves the structural reliability of the welding joint under complex working conditions and solves the problem of fatigue failure of the welding point that may occur during long-term use of the battery pack.

[0054] Specifically, after the current-carrying plate is connected to the terminal 312 of the cell 31 via laser welding, the welded joint needs to simultaneously bear the dual functions of current transmission and mechanical connection. During vehicle operation, it will be subjected to various loads such as vibration, impact, and thermal expansion and contraction. The contact between the boss 12 and the welded part provides distributed mechanical support for the weld point, dispersing the stress originally concentrated on the weld point to a larger contact area, significantly reducing the stress level at the weld point.

[0055] In one specific embodiment, the boss 12 is formed by stamping, and its height and shape are precisely designed to ensure that it can form appropriate contact pressure with the welding part of the current-carrying sheet after the battery pack is assembled. This contact pressure not only provides support for the weld joint, but also helps to maintain good conductivity of the contact surface and reduce the increase in resistance caused by poor contact. By supporting the welding part with the boss 12, an organic combination of welding connection and mechanical connection is achieved, forming a dual protection mechanism. Even if the weld joint has minor defects under extreme operating conditions, the mechanical support can still maintain the basic function of the connection, which greatly improves the long-term reliability and durability of the electrical connection.

[0056] like Figure 3 and Figure 4 As shown, in some embodiments, the boss 12 is an annular structure surrounding the pressure relief hole 11.

[0057] In this invention, the boss 12 is designed as a ring structure surrounding the pressure relief hole 11, realizing the integrated function of load support and pressure relief protection. The ring boss 12 not only provides a uniform support force distribution for the welding part of the current carrier plate, but also forms a structured protective area around the pressure relief hole 11, effectively preventing the impact damage of high-speed airflow to the edge structure of the pressure relief hole 11 during the pressure relief process.

[0058] Specifically, the annular structure has excellent load dispersion characteristics. When the current-carrying plate is connected to the battery cell 31 by welding, the weight and working load of the battery cell 31 are transferred to the bottom cover 1 through the current-carrying plate. The annular boss 12 converts these concentrated loads into surface loads distributed along the annular ring, avoiding load concentration at the edge of the pressure relief hole 11 and reducing the stress level in the local area of ​​the bottom cover 1. At the same time, the raised structure formed by the annular boss 12 around the pressure relief hole 11 can change the gas flow direction, playing a guiding and buffering role.

[0059] In related technologies, the support structure of the current-carrying plate and the pressure relief hole 11 are often set independently, which not only increases the structural complexity, but may also cause airflow turbulence due to structural interference during the pressure relief process, affecting the pressure relief effect, and may even cause damage to the support structure due to airflow impact. In this invention, the integrated design of the annular boss 12 simplifies the structure and improves the function. It provides reliable mechanical support under normal working conditions and provides effective structural protection under pressure relief conditions, realizing the organic unity of multiple functions and reflecting the high degree of integration and functional optimization of the design.

[0060] like Figure 5 As shown, in some embodiments, a positioning structure 21 for positioning the battery cell 31 is provided inside the top cover 2.

[0061] In this invention, a positioning structure 21 for positioning the battery cell 31 is provided inside the top cover 2, which provides a precise reference and constraint for the assembly of the battery pack, ensuring that each battery cell 31 can be accurately installed in the predetermined position, and ensuring the precise alignment between the battery cell 31 and the functional structures on the bottom cover 1. This not only improves the assembly accuracy, but also lays a reliable geometric foundation for subsequent electrical connections and safety protection functions.

[0062] Specifically, the positioning structure 21 provides positional constraints for the battery cell 31 in both the X and Y directions by setting mechanical constraint elements such as protrusions, grooves, or positioning pins on the inner surface of the top cover 2. When the battery cell 31 is placed inside the top cover 2, the positioning structure 21 guides the battery cell 31 to automatically position it in the correct location, eliminating random errors that may occur during manual positioning. The dimensional design of the positioning structure 21 takes into account the manufacturing tolerances and thermal expansion coefficient of the battery cell 31, achieving both reliable constraint and ease of assembly. At the same time, it ensures that the pressure relief structures 311 of all battery cells 31 correspond one-to-one with the pressure relief holes 11 on the bottom cover 1.

[0063] The positioning structure 21 inside the top cover 2 provides a standardized and automated positioning mechanism, which not only eliminates the influence of human factors, but also ensures that each battery pack can achieve consistent assembly quality in mass production, creating a stable and reliable foundation for key process links such as busbar welding, data acquisition line connection and pressure relief system alignment.

[0064] The present invention provides an automobile, comprising: a vehicle body; and the aforementioned automobile battery pack, wherein the automobile battery pack is disposed on the vehicle body, and the bottom cover 1 of the automobile battery pack constitutes at least a portion of the automobile chassis.

[0065] In this invention, the bottom cover 1 of the car battery pack constitutes at least part of the car chassis, realizing the deep integration of the battery pack structure and the body structure. This eliminates the problem of the battery pack being an independent module that requires additional brackets in traditional designs, significantly improving the integration and lightweighting of the overall vehicle structure. It not only optimizes space utilization efficiency but also enhances the overall rigidity and safety performance of the vehicle body.

[0066] Specifically, the bottom cover 1, as a component of the chassis, directly undertakes the structural functions of the vehicle body. The battery pack, through the top cover 2 and the integrated bottom cover 1, forms a complete load-bearing unit. The pressure relief hole 11 is directly opened on the chassis structure, achieving an organic unity between battery safety protection functions and vehicle body structural functions. The integrated chassis structure can also better utilize the load transfer path of the vehicle body, directly distributing the weight of the battery pack to the vehicle frame, thus improving the overall weight distribution of the vehicle.

[0067] In one specific embodiment, the integrated design of the battery pack bottom cover 1 and the vehicle chassis allows depressurized gas to be directly discharged from the bottom of the vehicle, eliminating the need for complex venting pipes and exhaust ports. This simplifies the structure of the depressurization system and reduces the risk of failure. Simultaneously, the integrated structure also improves the protection level of the battery pack and reduces the number of sealed interfaces.

[0068] In related technologies, battery packs are typically fixed as independent modules to specially designed mounting brackets using bolts, clips, or other connection methods. This not only increases the number of components and the overall vehicle weight but also introduces an additional connection interface between the battery pack and the vehicle body, increasing the complexity of sealing and maintenance. In contrast, the integrated chassis design of this invention fully leverages the advantages of structural integration. It not only reduces the overall vehicle weight and saves installation space but also makes the battery pack an integral part of the vehicle body structure, improving torsional rigidity and collision safety. Furthermore, it simplifies the implementation of the pressure relief system, reflecting the technological trend of modern automotive design towards high integration.

[0069] like Figure 7 As shown, the present invention provides a method for packaging the above-mentioned automotive battery pack, comprising the following steps: S1. Position the battery cell 31 of the battery module 3 inside the top cover 2; S2. Perform bus welding and acquisition line welding to electrically connect multiple battery cells 31; S3. Assemble the bottom cover 1 and the top cover 2, and press the battery module 3 together to form a battery pack; S4. Flip the entire battery pack so that the top cover 2 is facing upwards; S5. Inject sealant into the gap between the top cover 2 and the bottom cover 1.

[0070] In this invention, by employing a specific packaging process, the effects of gravity and the rationality of the process arrangement are fully utilized, achieving a dual improvement in assembly quality and production efficiency. This process scientifically arranges the timing of cell 31 positioning, electrical connection, mechanical assembly, and sealing, avoiding mutual interference between processes and ensuring that each step is completed under optimal conditions.

[0071] Specifically, the battery cell 31 is positioned inside the top cover 2 and naturally positioned by gravity, reducing the stress and deformation that may be caused by forced positioning; the busbar welding and acquisition line welding are completed before mechanical clamping to avoid the adverse effects of assembly stress on welding quality; the design of assembling and clamping the bottom cover 1 and the top cover 2 and then flipping the whole assembly ensures the stability of each component during assembly; finally, with the top cover 2 facing upwards, sealant is injected and gravity is used to allow the sealant to better penetrate into the gaps.

[0072] In one specific embodiment, after the battery cell 31 is positioned within the top cover 2, the welding of the busbar and the acquisition line is performed without external force constraints, resulting in more stable and controllable welding quality. The clamping force during the assembly of the bottom cover 1 acts directly on the welding area of ​​the current-carrying plate through the boss 12, forming mechanical support without generating harmful stress on the completed weld joint. This not only ensures the stability and consistency of assembly quality but also improves production efficiency and automation. In particular, the flip-over sealing process utilizes gravity-assisted flow and filling of the sealant, achieving a better sealing effect and demonstrating the scientific and practical nature of the process design.

[0073] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A car battery pack, characterized in that, include: A bottom cover and a top cover are provided, with a battery compartment formed between the bottom cover and the top cover. The bottom cover has multiple pressure relief holes. A battery module is disposed in the battery compartment. The battery module includes multiple battery cells. Each of the multiple battery cells has a pressure relief structure at one end facing the bottom cover. The multiple pressure relief structures are respectively disposed with multiple pressure relief holes.

2. The automotive battery pack according to claim 1, characterized in that, The pressure relief structure can form a pressure relief channel after rupture, and the pressure relief channel is connected to the pressure relief hole.

3. The automotive battery pack according to claim 2, characterized in that, The inner diameter of the pressure relief hole is larger than the diameter of the pressure relief channel.

4. The automotive battery pack according to claim 1, characterized in that, The pressure relief structure is concentrically arranged with the pressure relief hole.

5. The automotive battery pack according to claim 1, characterized in that, The pressure relief structure is located in the central region of the positive electrode of the battery cell.

6. The automotive battery pack according to any one of claims 1-5, characterized in that, The battery module also includes a current-carrying plate, which is welded to the terminal of the battery cell; The inner surface of the bottom cover is provided with a boss, which abuts against the welding part of the current-carrying plate and the electrode post.

7. The automotive battery pack according to claim 6, characterized in that, The boss is a ring-shaped structure surrounding the pressure relief hole.

8. The automotive battery pack according to any one of claims 1-5, characterized in that, The top cover is provided with a positioning structure for positioning the battery cell.

9. A car, characterized in that, include: Vehicle body; The vehicle battery pack as described in any one of claims 1-8, wherein the vehicle battery pack is disposed on the vehicle body, and the bottom cover of the vehicle battery pack constitutes at least a portion of the vehicle chassis.

10. A method for packaging an automotive battery pack as described in any one of claims 1-8, characterized in that, Includes the following steps: The battery cells of the battery module are positioned and placed inside the top cover; Perform busbar welding and data acquisition line welding to electrically connect multiple battery cells; The bottom cover is assembled with the top cover, and the battery module is pressed together to form a battery pack; Flip the entire battery pack so that the top cover is facing up; Inject sealant into the gap between the top cover and the bottom cover.

Images