Werkzeugakkupack

Abstract

A tool battery pack comprising a housing assembly, a cell assembly, a pole piece holder, and a control device, the housing assembly serving to receive the cell assembly, the pole piece holder, and the control device; the control device being connected to the pole piece holder and the cell assembly;wherein the cell assembly comprises unit cells and a cell holder, wherein the cell holder has an exposed hole, wherein the end of the cell holder of the exposed hole is the cell assembly end face, characterized in that it further comprises a barrier element with a heat-conducting effect, wherein the barrier element is arranged on a cell assembly end face by means of a positioning connector, wherein the cell assembly end face serves as a reference plane, wherein the barrier element has a first end face close to the reference plane and a second end face remote from the reference plane, wherein a distance G1 exists between the first end face and the cell assembly end face, wherein a pressure relief space is formed between the first end face and the cell assembly end face, wherein the pressure relief space has at least one pressure relief outlet.;

Description

Cross-reference to related applications

[0001] This application claims priority to Chinese patent application No. 202520348339.4, filed with the Chinese Patent Office on February 28, 2025, and entitled “Battery Pack,” and to Chinese patent application No. 202520561968.5, filed with the Chinese Patent Office on March 27, 2025, and entitled “Tool Battery Pack,” the entire contents of which are incorporated into this application by reference. Technical area

[0002] The embodiment of the application relates to the field of energy supply, in particular to a tool battery pack. Background technology

[0003] In existing tool battery packs, the battery pack typically consists of a single-parallel cell assembly or two-parallel cell assemblies. Due to the low power and the charging and discharging of the tool, the probability of thermal runaway in the battery pack is very low, and no barrier material is provided. However, with the increase in tool power, the requirements for the battery pack capacity and the charging and discharging speed also become more stringent. Due to the increase in charging and discharging speed, the local temperature gradient expands, and the risk of thermal runaway is significantly increased. If this is not taken seriously, it can cause damage to the battery pack, tools, and user safety issues. In the field of power batteries, it is typically used to solve cell thermal runaway.For this purpose, heat-resistant materials such as mica foils and aerogel films are used to block the cell end face. These heat-resistant materials can effectively isolate the high-temperature and high-pressure gases and liquids emitted from the cell, preventing them from causing secondary damage to the surrounding environment and other cells. However, these conventional barrier methods have some shortcomings and limitations. Although these materials provide good thermal insulation, the high-temperature gases released during a thermal runaway event cannot be quickly dissipated, which can lead to a continuous rise in the internal temperature, which is not conducive to rapid heat dissipation and triggers a temperature rise in neighboring battery cells.If the accumulated heat is not dissipated in a timely manner, it can be conducted through the cell casing or the interconnect element, triggering failure of other areas and increasing the risk of thermal runaway of the entire battery pack. Content of the utility model

[0004] The aim of this application is to provide a tool battery pack that solves the problems of high-temperature gas retention and secondary thermal runaway of the tool battery pack, and to realize a solution with light weight, efficient heat dissipation, and safe insulation.

[0005] The present application provides one embodiment of a tool battery pack. A tool battery pack is provided with a housing assembly, a cell assembly, a pole piece holder, and a control device, wherein the housing assembly serves to receive the cell assembly, the pole piece holder, and the control device; wherein the control device is connected to the pole piece holder and the cell assembly; wherein the cell assembly comprises unit cells and a cell holder, wherein the cell holder has an exposed hole, wherein the end of the cell holder with the exposed hole is the cell assembly end face.A tool battery pack further comprises a barrier element with a heat-conducting effect, wherein the barrier element is arranged on a cell assembly end face by means of a positioning connector, wherein the cell assembly end face serves as a reference plane, wherein the barrier element has a first end face close to the reference plane and a second end face remote from the reference plane, wherein a distance G1 exists between the first end face and the cell assembly end face, wherein a pressure relief space is formed between the first end face and the cell assembly end face, wherein the pressure relief space has at least one pressure relief outlet.Compared with existing tool battery packs that are not configured with a barrier element, so that when the unit cell is in thermal runaway, it is not possible to achieve thermal diffusion of high-temperature gases and flames flowing out from the cell end face toward the case assembly and / or the cell assembly, so that it is ruptured and destroyed, this application establishes the pressure relief space formed between the barrier element and the cell assembly end face, together with the design of the pressure relief outlets, a directional pressure relief mechanism and can guide high-temperature gases and flames generated by thermal runaway directly to a predetermined safe area to effectively reduce the risk of internal pressure buildup.At the same time, it performs a dual role of barrier and protection. The thermally conductive barrier element can be used as a physical barrier to prevent the flame from directly impacting the case and / or adjacent cells. The local high temperature can also be quickly dissipated to the entire heat dissipation system of the battery pack through its thermal conductivity, so that the gaseous flame is extinguished by the cooling effect of the metal surface in the gap, and the solid melt is blocked in the pressure relief space to prevent splashing onto adjacent cells. This can significantly reduce the probability of fire, explosion, and other accidents in the entire battery pack in the event of a unit cell thermal runaway, and improve the overall reliability and safety of the battery.

[0006] Optionally, the gap G1 is greater than or equal to 1 mm and less than 10 mm. By precisely controlling the gap (G1), the initial heat wave can be blocked and the heat wave is directed toward a specific space for pressure relief, which has the effect of effectively limiting the heat wave in the thermally burned unit cell with the thermal propagation in all four directions of the adjacent unit cell and / or the housing assembly 1. This realizes that it is to some extent delayed or prevented from thermal runaway from being transmitted from one cell to the entire tool battery pack. It also ensures that the overall size of the tool battery pack does not become too large, so that the tool battery pack design can still be applied to existing tools and equipment while maintaining safety and performance.A standardized gap size makes the system easier and more efficient to operate during the production and assembly process.

[0007] Optionally, the barrier element is made of a rigid material with a flash point of 300°C or higher. Using a material with a flash point of 300°C or higher ensures that the barrier element maintains its structural integrity in high-temperature environments or in the event of a cell thermal runaway, preventing it from easily burning or decomposing, and improves the safety of the battery system. The rigid material also provides better resistance to thermal conduction, effectively preventing the transmission of flames or high temperatures to neighboring cells and reducing the risk of a propagating thermal runaway. Under extreme conditions, the material can act as a flame barrier to protect the internal cells from the outside world or other heat sources that may be generated by the cells.

[0008] Optionally, the barrier element is made of metal, and the gap G1 is greater than or equal to 1 mm and less than 10 mm. The metal barrier element forms a non-contact thermal conduction channel with the cell end face through the gap G1, which can quickly dissipate local high-temperature heat laterally to the cooling surface of the package during thermal runaway. The metal barrier element forms an elastic buffer layer in the region of the gap G1. When the cell burst pressure suddenly increases, the impact energy is absorbed by metal deformation, and the pressure in the gap space is dampened to form a strong dynamic impact resistance.

[0009] Optionally, the thickness J of the barrier element, corresponding to the cell end face area, is greater than or equal to 0.8 mm and less than or equal to 3 mm. It can provide sufficient space for pressure relief while maintaining structural strength when the thickness J of the barrier element is in a range greater than or equal to 0.8 mm and less than or equal to 3 mm. This thickness contributes to effective pressure conduction and release under extreme conditions (e.g., thermal runaway).The thickness range is also sufficient to provide effective thermal insulation and slow heat conduction from one cell to neighboring cells, increasing the safety of the battery system and ensuring that the barrier element does not add excessive weight or take up too much space while providing support and insulation, ensuring overall low weight and compactness of the tool battery pack.

[0010] Optionally, the cell end face comprises a first cell end face and a second cell end face, wherein the cell assembly end face comprises at least 2 cell end faces, wherein the thickness of the barrier element corresponding to the area of ​​the first cell end face is less than or equal to 1 mm when subtracted from the thickness of the barrier element corresponding to the area of ​​the second cell end face.By controlling the thickness difference between the barrier elements corresponding to the first cell end face and the second cell end face, the thicker barrier element in the high-frequency thermal runaway region has a higher local heat capacity due to more materials, which can absorb more heat and slow the temperature rise rate. At the same time, its thermal conductivity path can quickly conduct heat to the heat dissipation structure of the housing to avoid heat buildup. The thinner barrier element in the low-frequency region prioritizes ensuring heat dissipation efficiency and prevents abnormal local temperature rise due to rapid thermal conductivity. This achieves a differentiated response of the pressure relief chamber.

[0011] Optionally, the thickness of the barrier element corresponding to the area of ​​the first cell end face is equal to the thickness of the barrier element corresponding to the area of ​​the second cell end face for ease of manufacture.

[0012] Optionally, the thickness of the barrier element corresponding to the area of ​​the first cell end face is greater than the thickness of the barrier element corresponding to the area of ​​the second cell end face. The first cell end face is located at the position where high-frequency thermal runaway occurs and high-temperature and high-pressure gases are discharged. The thickness of the barrier element here is relatively thick, forming a relatively small pressure relief space, which can form greater resistance to the high-pressure gas erupting in the early stage of thermal runaway, slow down the gas flow rate, and reduce the immediate impact on the pressure relief outlet. The second cell end face is located at the position where low-frequency and high-frequency thermal runaway occurs and high-temperature and high-pressure gases are discharged.The thickness of the barrier element here is relatively thick and forms a relatively large pressure relief space, which can absorb more gas expansion, buffer pressure fluctuations and realize a differentiated response to the pressure relief space.

[0013] Optionally, the first end surface of the barrier element corresponding to the cell end surface area has a convex structure away from the reference plane, and / or, optionally, the second end surface of the barrier element corresponding to the cell end surface area has a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end surface and the cell end surface can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively by natural convection. The cell generates heat during the charging and discharging process.A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0014] Optionally, the first end face and the second end face of the barrier element, which correspond to the area of ​​the cell end face, are both planar.

[0015] Optionally, the pressure relief outlet is provided on the barrier element and / or the cell assembly end face and / or the cell holder. The pressure relief outlet is provided on the surface of the pressure relief space between the first end face and the cell assembly end face. By arranging the pressure relief outlet on various components, it can be flexibly adapted to the specific design and thermal management requirements of the tool battery pack, optimize the pressure relief effect, reduce internal pressure buildup, and also help maintain the physical integrity and stability of the tool battery pack, prevent physical damage and potential safety accidents caused by excessive pressure, and work in conjunction with groove-shaped or flat barrier elements.The pressure relief chamber can not only contribute to pressure relief, but also assists to a certain extent in the dissipation of heat waves and further slows down the uncontrolled spread of heat.

[0016] Optionally, the pressure relief outlet is arranged on the end face of the barrier element between unit cells at the cell head, which does not correspond to the area of ​​the cell end face. The arrangement parallel to the cell assembly end face ensures the directness and smoothness of the pressure relief path. When thermal runaway occurs, the pressure relief space allows the internal pressure of the thermally runaway unit cell to be quickly and efficiently released directly along the internal pressure relief path of the cell parallel to the cell assembly end face, thereby quickly mitigating the effects of local temperature rise and preventing rapid heat buildup.

[0017] Optionally, the projection area of ​​the barrier element's end face is greater than or equal to the maximum projection area of ​​the adjacent cell assembly end face. Because the projection area of ​​the barrier element's end face is greater than or equal to the maximum projection area of ​​the adjacent cell assembly end face, the barrier element can completely cover the maximum projection area of ​​the cell assembly end face, allowing for better control and management of the heat diffusion path. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events.

[0018] Optionally, the projection area of ​​the barrier element's end face is smaller than the projection area of ​​the adjacent cell assembly end face. The maximum projection area of ​​the barrier element is greater than or equal to the projection area of ​​the maximum outer size of all cell end faces of the cell assembly end face. The barrier element can completely cover the maximum projection area of ​​the cell assembly end face, so that the heat diffusion path can be better controlled and managed. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway transmission, and can fully protect the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0019] Optionally, the housing assembly includes a first cooling vent and a second cooling vent. The first cooling vent serves as the air inlet, and the second cooling vent serves as the air outlet. The pressure relief airflow from the pressure relief outlet is exhausted through the second cooling vent. During thermal runaway, the high-temperature and / or high-pressure gas from the pressure relief outlet is directed through the second heat dissipation vent (air outlet), so that the pressure relief airflow and the heat dissipation airflow at the outlet form a superposition effect in the same direction, accelerating the hazardous gas away from the core area of ​​the battery pack and preventing internal gas retention.

[0020] Optionally, the pressure relief air flow from the pressure relief outlet flows through the second cooling opening, and the material of the second cooling opening is plastic.

[0021] Optionally, the pressure relief airflow from the pressure relief outlet flows through the second cooling vent, which is made of metal. When the high-temperature gas flows through the metal cooling vent, the heat is quickly transferred through the metal surface to the battery pack casing or the external environment, thereby reducing the temperature of the discharged gas and reducing thermal damage to peripheral components. The metal cooling vent serves as an additional heat dissipation channel and works in conjunction with the thermal conductivity path of the barrier element to accelerate overall heat dissipation within the battery pack.

[0022] Optionally, the pressure relief airflow from the pressure relief outlet flows through the second cooling port. The second cooling port features a pressure relief valve that serves as a conventional cooling channel to help the device maintain normal operating temperature. If the pressure is too high, the pressure relief valve is activated to release the airflow through this port and achieve pressure relief.

[0023] This application also provides an embodiment of the tool battery pack.

[0024] A tool battery pack is provided with a housing assembly, a cell assembly, a pole piece holder, and a control device, wherein the housing assembly serves to accommodate the cell assembly, the pole piece holder, and the control device; wherein the control device is connected to the pole piece holder and the cell assembly; wherein the cell assembly comprises unit cells, a cell holder, a first cell assembly, a second assembly, and a cell assembly connector connecting the first cell assembly to the second assembly, wherein the cell holder has an exposed hole, wherein the end of the cell holder with the exposed hole is the cell assembly end face, wherein the first cell assembly comprises a first cell assembly end face and a second cell assembly end face, wherein the second cell assembly comprises a third cell assembly end face and a fourth cell assembly end face,wherein the third cell assembly end face is opposite the second cell assembly end face. It further comprises a barrier element, wherein the barrier element is arranged between the third cell assembly end face and the second cell assembly end face by means of a positioning connector, wherein the third cell assembly end face serves as a reference plane, wherein the barrier element has a first end face close to the reference plane and a second end face remote from the reference plane, wherein a first pressure relief space is formed between the first end face and the third cell assembly end face, wherein a distance G1 exists between the first end face and the third cell assembly end face, wherein a second pressure relief space is formed between the second end face and the second cell assembly end face, wherein a distance G2 exists between the second end face and the second cell assembly end face,wherein the first pressure relief chamber and the second pressure relief chamber have at least one pressure relief outlet. Compared to existing tool battery packs that are not configured with a barrier element, such that when the unit cell is in thermal runaway, it is not possible to achieve thermal diffusion of high-temperature gases and flames flowing from the cell end face toward the housing assembly and / or the cell assembly, causing it to rupture and destroy. In this application, the barrier element is arranged between the third cell assembly end face and the second cell assembly end face, thus introducing a relatively independent pressure relief chamber between adjacent cell assemblies to form a physical barrier. The pressure relief chamber formed between the barrier element and the cell assembly end faceTogether with the design of the pressure relief outlets, it establishes a directional pressure relief mechanism and can direct high-temperature gases and flames generated by thermal runaway to a predetermined safe area, effectively reducing the risk of internal pressure buildup, so that the probability of fires, explosions, and other accidents in the entire battery pack in the event of a thermal runaway of the unit cell can be significantly reduced and the overall reliability and safety of the battery can be improved.

[0025] Optionally, the gap G1 is greater than or equal to 1 mm and less than 10 mm, and / or the gap G2 is greater than or equal to 1 mm and less than 10 mm. By precisely controlling the gap (G1, G2), the initial heat wave can be blocked and the heat wave is directed toward a specific space for pressure relief, which effectively limits the heat wave in the thermally burned unit cell with the thermal propagation in all four directions of the adjacent unit cell. This achieves a certain delay or prevention of thermal runaway from one cell being transmitted to the entire tool battery pack. It also ensures that the overall size of the tool battery pack is not too large, so that the tool battery pack design can still be applied to existing tools and equipment while maintaining safety and performance.A standardized gap size makes the system easier and more efficient to operate during the production and assembly process.

[0026] Optionally, the difference between the distance G1 and the distance G2 is 1 mm or less. The difference ΔG forms an asymmetric heat conduction path, which enables differentiated control of heat propagation in the space, increasing the gap in high-risk areas such as the positive terminal cell end face and narrowing the gap in the negative terminal cell end face in low-risk areas, making heat management more flexible and efficient. Detailed space management optimizes the safety performance of the tool battery pack during thermal runaway while ensuring its compactness and applicability. This design enhances the practical application effect of the tool battery pack.

[0027] Optionally, the distance G1 and the distance G2 are equal. Because the distance G1 and the distance G2 are equal, the compensation interval is in the early stage of thermal runaway. The symmetrical distance G1 / G2 causes the high-temperature gas to be discharged from the first space and the second pressure relief space in parallel at the same flow rate, avoiding local air turbulence caused by uneven pressure relief and reducing the risk of heat wave superposition. The equidistant design of the double pressure relief space forms a pressure relief compensation mechanism in both directions.If abnormal gas production occurs on one side of the cell assembly, the symmetrical channel can automatically equalize the pressure difference on both sides, preventing structural deformation caused by overstress on one side and simultaneously suppressing a chain reaction of thermal runaway. The balanced pressure relief channel allows heat to be evenly distributed along the axial direction of the battery pack. Combined with the high-temperature resistance properties of the barrier element, the problem of thermal stress concentration between cells is significantly reduced.

[0028] Optionally, the unit cell comprises a cell end face and a cell main body, wherein the thickness J of the barrier element corresponding to the cell end face area is greater than or equal to 0.8 mm and less than or equal to 3 mm. It can provide sufficient space for pressure relief while maintaining structural strength when the thickness J of the barrier element is in a range of greater than or equal to 0.8 mm and less than or equal to 3 mm. This thickness contributes to effective pressure conduction and release under extreme conditions (e.g., thermal runaway).The thickness range is also sufficient to provide effective thermal insulation and slow heat conduction from one cell to neighboring cells, increasing the safety of the battery system and ensuring that the barrier element does not add excessive weight or take up too much space while providing support and insulation, ensuring overall low weight and compactness of the tool battery pack.

[0029] Optionally, to facilitate manufacturing, the cell end face comprises a first cell end face and a second cell end face, wherein the cell assembly end face comprises at least 2 cell end faces, wherein the thickness of the barrier element corresponding to the area of ​​the first cell end face is less than or equal to 1 mm when subtracted from the thickness of the barrier element corresponding to the area of ​​the second cell end face.By controlling the thickness difference between the barrier elements corresponding to the first cell end face and the second cell end face, the thicker barrier element in the high-frequency thermal runaway region has a higher local heat capacity due to more materials, which can absorb more heat and slow the temperature rise rate. At the same time, its thermal conductivity path can quickly conduct heat to the heat dissipation structure of the housing to avoid heat accumulation. The thinner barrier element in the low-frequency region prioritizes ensuring heat dissipation efficiency and prevents abnormal local temperature rise due to rapid thermal conductivity. This achieves a differentiated response of the pressure relief chamber.

[0030] Optionally, the thickness of the barrier element corresponding to the area of ​​the first cell end face is equal to the thickness of the barrier element corresponding to the area of ​​the second cell end face for ease of manufacture.

[0031] Optionally, the thickness of the barrier element corresponding to the area of ​​the first cell end face is greater than the thickness of the barrier element corresponding to the area of ​​the second cell end face. The first cell end face is located at the position where high-frequency thermal runaway occurs and high-temperature and high-pressure gases are discharged. The thickness of the barrier element here is relatively thick, forming a relatively small pressure relief space, which can form greater resistance to the high-pressure gas erupting in the early stage of thermal runaway, slow down the gas flow rate, and reduce the immediate impact on the pressure relief outlet. The second cell end face is located at the position where low-frequency and high-frequency thermal runaway occurs and high-temperature and high-pressure gases are discharged.The thickness of the barrier element here is relatively thick and forms a relatively large pressure relief space, which can absorb more gas expansion, buffer pressure fluctuations and realize a differentiated response to the pressure relief space.

[0032] Optionally, the first end surface of the barrier element corresponding to the cell end surface area has a convex structure away from the reference plane, and / or, optionally, the second end surface of the barrier element corresponding to the cell end surface area has a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end surface and the cell end surface can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively by natural convection. The cell generates heat during the charging and discharging process.A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0033] Optionally, the first end face and the second end face of the barrier element, which correspond to the area of ​​the cell end face, are both planar.

[0034] Optionally, the pressure relief outlet is provided on the barrier element and / or the cell assembly end face and / or the cell holder. The pressure relief outlet is provided on the surface of the pressure relief space between the first end face and the cell assembly end face. By arranging the pressure relief outlet on various components, it can be flexibly adapted to the specific design and thermal management requirements of the tool battery pack, optimize the pressure relief effect, reduce internal pressure buildup, and also help maintain the physical integrity and stability of the tool battery pack, prevent physical damage and potential safety accidents caused by excessive pressure, and work in conjunction with groove-shaped or flat barrier elements.The pressure relief chamber can not only contribute to pressure relief, but also assists to a certain extent in the dissipation of heat waves and further slows down the uncontrolled spread of heat.

[0035] Optionally, the pressure relief outlet is arranged on the end face of the barrier element between unit cells at the cell head, which does not correspond to the area of ​​the cell end face. The arrangement parallel to the cell assembly end face ensures the directness and smoothness of the pressure relief path. When thermal runaway occurs, the pressure relief space allows the internal pressure of the thermally runaway unit cell to be quickly and efficiently released directly along the internal pressure relief path of the cell parallel to the cell assembly end face, thereby quickly mitigating the effects of local temperature rise and preventing rapid heat buildup.

[0036] Optionally, the projection area of ​​the barrier element's end face is greater than or equal to the maximum projection area of ​​the adjacent cell assembly end face and can completely cover the maximum projection area of ​​the adjacent cell assembly end face. Because the barrier element is greater than or equal to the maximum projection area of ​​the adjacent cell assembly end face, the barrier element can completely cover the maximum projection area of ​​the cell assembly end face, allowing for better control and management of the heat diffusion path. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events.

[0037] Optionally, the projection area of ​​the end face of the barrier element is smaller than the maximum projection area of ​​the adjacent cell assembly end face. If the projection area of ​​all cell end faces of the third cell assembly end faces is equal to the projection area of ​​all cell end faces of the second cell assembly end faces and their shapes match, the shape of the barrier element is greater than or equal to the projection area of ​​all cell end faces of the adjacent cell assembly end faces; or if the projection area of ​​all cell end faces of the third cell assembly end face is identical to the projection area of ​​all cell end faces of the second cell assembly end faces, but not positionally corresponding, or the projection area of ​​all cell end faces of the second cell assembly end faces is neither identical nor positionally corresponding, the projection area of ​​the end face of the barrier element is greater than or equal to the maximum projection area resulting from a union of the maximum projection area of ​​all cell end faces of the second cell assembly end faces and the maximum projection area of ​​all cell end faces of the third cell assembly end faces, so that the diffusion path of the heat can be better controlled and regulated.This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events and fully protecting the cell end face. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0038] Optionally, the housing assembly includes a first cooling vent and a second cooling vent. The first cooling vent serves as the air inlet, and the second cooling vent serves as the air outlet. The pressure relief airflow from the pressure relief outlet is exhausted through the second cooling vent. During thermal runaway, the high-temperature and / or high-pressure gas from the pressure relief outlet is directed through the second heat dissipation vent (air outlet), so that the pressure relief airflow and the heat dissipation airflow at the outlet form a superposition effect in the same direction, accelerating the hazardous gas away from the core area of ​​the battery pack and preventing internal gas retention.

[0039] Optionally, the barrier element is made of a rigid material with a flash point of 300°C or higher. At the same time, it fulfills a dual role of barrier and protection. The barrier element with thermal conductivity can be used as a physical barrier to prevent the flame from directly impacting the casing and / or adjacent cells. The local high temperature can also be quickly distributed to the entire heat dissipation system of the battery pack through its thermal conductivity properties. This extinguishes the gaseous flame due to the cooling effect of the metal surface in the gap, and blocks the solid melt in the pressure relief space to prevent splashing onto adjacent cells. This significantly reduces the probability of fire, explosion, and other accidents affecting the entire battery pack in the event of a unit cell thermal runaway, and improves the overall reliability and safety of the battery pack.

[0040] Optionally, the barrier element is made of a rigid material with a flash point of 300°C or higher. Using a material with a flash point of 300°C or higher ensures that the barrier element maintains its structural integrity in high-temperature environments or in the event of a cell thermal runaway, preventing it from easily burning or decomposing, and improves the safety of the battery system. The rigid material also provides better resistance to thermal conduction, effectively preventing the transmission of flames or high temperatures to neighboring cells and reducing the risk of a propagating thermal runaway. Under extreme conditions, the material can act as a flame barrier to protect the internal cells from the outside world or other heat sources that may be generated by the cells.

[0041] Optionally, the barrier element is made of a metallic material. The metal barrier element forms a non-contact thermal conductivity channel with the cell end face through the gap G1, which can quickly dissipate local high-temperature heat laterally to the cooling surface of the housing during thermal runaway. The metal barrier element forms an elastic buffer layer in the area of ​​the gap G1. When the cell burst pressure suddenly increases, the impact energy is absorbed by metal deformation, and the pressure in the gap space is dampened to form a strong dynamic impact resistance.

[0042] Optionally, the barrier element is a metal material containing aluminum. The high thermal conductivity of aluminum allows the barrier element to quickly absorb the local high heat generated during thermal runaway. The heat is transferred to the heat dissipation area of ​​the battery pack casing along the longitudinal direction perpendicular to the cell stacking direction, thereby avoiding horizontal heat diffusion between the cells. At the same volume, the aluminum-containing material is used as the barrier element. It is lightweight and suitable for scenarios where the battery pack becomes increasingly heavy under the high power requirements of the tool, thus achieving breakthroughs in thermal management, lightweight design, and manufacturing costs.

[0043] Optionally, the pressure relief air flow from the pressure relief outlet flows through the second cooling opening, and the material of the second cooling opening is plastic.

[0044] Optionally, the pressure relief airflow from the pressure relief outlet flows through the second cooling vent, which is made of metal. When the high-temperature gas flows through the metal cooling vent, the heat is quickly transferred through the metal surface to the battery pack casing or the external environment, thereby reducing the temperature of the discharged gas and reducing thermal damage to peripheral components. The metal cooling vent serves as an additional heat dissipation channel and works in conjunction with the thermal conductivity path of the barrier element to accelerate overall heat dissipation within the battery pack.

[0045] Optionally, the pressure relief airflow from the pressure relief outlet flows through the second cooling port. The second cooling port features a pressure relief valve that serves as a conventional cooling channel to help the device maintain normal operating temperature. If the pressure is too high, the pressure relief valve is activated to release the airflow through this port and achieve pressure relief. Illustration of the attached drawings

[0046] One or more embodiments are illustrated by way of example with reference to the figures of the accompanying drawings, wherein the exemplary figures do not represent a limitation of the embodiments. Fig. 1 is a three-dimensional plan view of a tool battery pack provided by an embodiment of the present application; Fig. 2 is a bottom three-dimensional view of a tool battery pack provided by an embodiment of the present application; Fig. 3 is a view of the internal structure of a tool battery pack provided by an embodiment of the present application; Fig. 4 is a cross-sectional view of the assembly of the partial barrier member, the cell holder, and the unit cell of a tool battery pack provided by an embodiment of the present application; Fig. 5 is a cross-sectional view of a unit cell provided by an embodiment of the present application; Fig. 6 is a partial sectional view of the internal structure of a tool battery pack provided by an embodiment of the present application, with the waterproofing layer and the barrier member hidden; Fig. 7 is a sectional view of the assembly of a barrier member, a cell holder, and a unit cell of the tool battery pack provided by an embodiment of the present application; Fig. 8 is a view of a barrier plate of the tool battery pack provided by an embodiment of the present application; Fig. 9 is a view of a barrier plate of the tool battery pack provided by an embodiment of the present application; Fig. 10 is a view of the proportions between the cell end face and the barrier element provided by an embodiment of the present application; Fig. 11 is a partial cross-sectional view of a barrier plate of the tool battery pack provided by an embodiment of the present application; Fig. 12 is a graph of temperature change data of a 60V cell and cell end area from the tool battery pack in a 30A discharge mode provided by an embodiment of the present application; Fig. 13 is a graph of temperature change data of a thermally runaway cell and neighboring cells provided by an embodiment of the tool battery pack of the present application; Fig. 14 is a view of the internal structure of a tool battery pack provided by an embodiment of the present application; Fig. 15 is a sectional view of the assembly of a barrier plate, a cell holder, and a unit cell of the tool battery pack provided by an embodiment of the present application; Fig. 16 is an exploded diagram of the assembly of a barrier plate, a cell holder, and a unit cell of the tool battery pack provided by an embodiment of the present application; Fig. 17 is an exploded diagram of the assembly of a barrier plate, a water sealing member, a cell holder, and a unit cell provided by an embodiment of the present application; Fig. 18 is a view of the water sealing member in the tool battery pack provided by an embodiment of the present application; Fig. 19 is a view of the water sealing member in the tool battery pack provided by an embodiment of the present application; Fig. 20 is a view of the water sealing member in the tool battery pack provided by an embodiment of the present application; Fig. 21 is a sectional view at the magnified position A of the water sealing member in the tool battery pack provided by an embodiment of the present application; Fig. 22 is a sectional view at the magnified position A of the water sealing member in the tool battery pack provided by an embodiment of the present application; Fig. 23 is an assembly view of a waterproofing member, a waterproofing layer, a cell holder, and a unit cell in the tool battery pack provided by an embodiment of the present application; Fig. 24 is an assembly view of a waterproofing member, a waterproofing layer, a cell holder, and a unit cell in the tool battery pack provided by an embodiment of the present application; Fig. 25 is a view of the pole piece holder of the tool battery pack provided by an embodiment of the present application; Fig. 26 is a view of the pole piece holder of the tool battery pack provided by an embodiment of the present application; Fig. 27 is a view of the tool battery pack provided by an embodiment of the present application; Fig. 28 is a view of the tool battery pack provided by an embodiment of the present application; Fig. 29 is a view of the control device of a tool battery pack provided by an embodiment of the present application; Fig. 30 is a view of the control device of a tool battery pack provided by an embodiment of the present application. Specific embodiments

[0047] In the field of existing tool battery packs, the state-of-the-art battery pack typically consists of a single-parallel cell assembly or two-parallel cell assemblies. Due to the low power and the charging and discharging of the tool, the probability of thermal runaway in the battery pack is very low, and no barrier material is provided. However, with the increase in tool power, the requirements for the battery pack capacity and the charging and discharging speed also become higher. Due to the increase in charging and discharging speed, the local temperature gradient expands, and the risk of thermal runaway is significantly increased. If not taken seriously, it can cause damage to the battery pack, tools, and user safety issues. In the field of power batteries, it is commonly used to solve cell thermal runaway.For this purpose, heat-resistant materials such as mica foils and aerogel films are used to block the cell end face. These heat-resistant materials can effectively isolate the high-temperature and high-pressure gases and liquids emitted from the cell, preventing them from causing secondary damage to the surrounding environment and other cells. However, these conventional barrier methods have some shortcomings and limitations. Although these materials provide good thermal insulation, the high-temperature gases released during a thermal runaway event cannot be quickly dissipated, which can lead to a continuous rise in the internal temperature, which is not conducive to rapid heat dissipation and triggers a temperature rise in neighboring battery cells.If the accumulated heat is not dissipated in a timely manner, it can be conducted through the cell casing or the interconnect element, triggering failure of other areas and increasing the risk of thermal runaway of the entire battery pack.

[0048] The temperature rise of the cell end surface of the 60V unit cell 23 in the discharge process with 30A is as in Fig. 12 and Fig. 13 approximately 60°C. As the current increases, the temperature rise of the cell end surface also increases. If the temperature of the cell end surface of the unit cell continues to rise during the charging and discharging process, and when the cell end surface temperature reaches 100°C, the surface temperature of the adjacent cell will continue to rise as the temperature of the thermally runaway cell rises. And the thermally runaway cell will experience irreversible overheating at 283.6°C, causing the end surface temperature of the unit cell to rise rapidly. A fire usually occurs at high voltage and high temperature in the area of ​​the first cell end surface 211.If the thermally runaway cell is not controlled, the surface temperature of the adjacent cell will be affected by the heat propagation from the cell of the thermally runaway unit, and the thermal runaway cell may spread to the entire battery pack. If the thermally runaway cell is not controlled, the surface temperature of the adjacent cell will be affected by the heat propagation from the thermally runaway cell, and the thermal runaway may spread to the entire battery pack.

[0049] The inventor of the present application identified the above-mentioned deficiencies and analyzed their causes by investigating the internal temperatures of overtemperature cells and thermally runaway cells in power tool battery packs, as well as the heat transfer within the battery pack as a whole. Through the targeted placement of barrier elements and a suitable structural and material design, the problem of excessive volume in power tool battery packs, as well as the accumulation of hot gases and the resulting secondary thermal runaway processes, was effectively overcome.

[0050] In order to clarify the purpose, technical solutions, and advantages of the embodiments of the present application, the various embodiments of the present application are described in detail below in conjunction with the accompanying drawings. A person skilled in the art will appreciate that in the various embodiments of the present application, certain technical details are disclosed merely for clarity. Even without these technical details, as well as without various variations and modifications based on the following embodiments, the technical solution to be protected by the present application can be achieved. The following embodiments are divided for the sake of simplicity and do not represent a limitation on the specific configuration of the present application.Each embodiment may be combined with or refer to any other, provided they do not contradict each other.

[0051] Fig. 1 - Fig. 13 is a view of the structure of the tool battery pack provided by an embodiment of the present application.

[0052] An example of the tool battery pack

[0053] A tool battery pack like in Fig. 1-3 comprises a housing assembly 1, a cell assembly 2, a pole piece holder 3, and a control device 4, wherein the housing assembly 1 is used to accommodate the cell assembly 2, the pole piece holder 3, and the control device 4; wherein the control device 4 is connected to the pole piece holder 3 and the cell assembly 2;

[0054] The housing assembly 1 has a holder seat (not shown), an opening 13, the opening 13 being arranged corresponding to the location of the pole piece holder 3 in the housing assembly 1 for the tool pole piece to penetrate it and connect to the pole piece holder 3; the holder seat (not shown) being provided on at least one side within the housing assembly 1 for securing the electrical cell assembly 2.

[0055] In one embodiment, the housing assembly 1 has a first cooling opening 11, a holder seat (not shown), an opening 13, and a second cooling opening 14. The housing assembly 1 is used to accommodate the cell assembly 2, the pole piece holder 3, and the control device 4; the opening 13 is arranged corresponding to the location of the pole piece holder 3 in the housing assembly 1 so that the tool pole piece penetrates it and connects to the pole piece holder 3.wherein a second cooling opening 14 is arranged on the side of the battery pack with the opening 13, wherein the first cooling opening 11 and the second cooling opening 14 are provided opposite each other on the surface of the housing assembly 1, wherein the first cooling opening 11 is an air inlet, while the second cooling opening 14 is an air outlet, wherein a linear air channel is formed by the arrangement of the first cooling opening 11 and the second cooling opening 14, so that such a direct ventilation path helps the airflow to flow through the battery pack more efficiently, thereby ensuring that the internal temperature of the battery pack is always kept within a safe range, which greatly improves the heat dissipation efficiency of the battery pack and reduces the risk of explosion caused by cell overheating;wherein holder seats (not shown) are provided on at least one side of the housing assembly 1 for fixing the cell assembly 2 to prevent movement of the cell holder 22 in the housing assembly 1; wherein the total area of ​​the first cooling opening 11 is larger than the total area of ​​the second cooling opening 14, wherein the air flow enters the housing assembly 1 through the first cooling opening 11 and is then discharged from the second cooling opening 14, wherein the first cooling opening 11 has a larger area which promotes the introduction of more cold air so that the cold air can fully come into contact with the cell assembly 2;

[0056] As in Fig. 4-6, the cell assembly 2 comprises a unit cell 23, a cell holder 24, the unit cell 23 having a cell end face 231 and a cell main body 232, the cell end face 231 having a first cell end face 2311 and a second cell end face 2312.

[0057] In an embodiment as in Fig. 5, the unit cell 23 is a cylindrical cell, wherein the first cell end face 2311 has a positive pole end face 23111 and the positive pole end face 23111 is a planar end face, wherein the second cell end face 2312 is a negative pole end face.

[0058] In an embodiment as in Fig. 5, the unit cell 23 is a cylindrical cell, wherein the first cell end face 2311 has a positive pole end face 23111 and the positive pole end face 23111 has a cap end face 231111, the cap end face 231111 protruding outwardly from the positive pole end face 23111, the second cell end face 2312 being a negative pole end face.

[0059] In an embodiment as in Fig. 5, the unit cell 23 is a cylindrical cell, with the first cell end face 2311 having a positive terminal end face 23111 and also a negative terminal end face 23112. A separator 23113 is provided between the negative terminal end face 23112 and the positive terminal end face 23111 to isolate the positive electrode from the negative electrode to prevent a short circuit.

[0060] As in Fig. 7, the cell holder 24 has a receiving slot 241, an exposed hole 242, a first end 243, a second end 244, wherein the first end 243 of the cell holder 24 has a receiving slot 241 that receives the unit cell 23, wherein one end of the receiving slot 241 has a groove into which the unit cell 23 projects, wherein the other end of the receiving slot 241 has an exposed hole 242 that extends through the cell holder 24, wherein the exposed hole 242 is arranged at the second end 244, wherein the area within the hole is smaller than the cross-sectional area of ​​the receiving slot 241, which is parallel to the exposed hole 242, wherein the area of ​​the exposed hole 242 is smaller than the maximum area of ​​the first cell end surface that extends into the receiving slot 241, wherein one end of the cell holder 24 with the exposed hole 242 is a cell assembly end face,wherein the shape of the exposed hole 242 includes, but is not limited to, a rounded shape, an oval shape, a square shape, and other shapes; wherein the cell holder 24 is securely attached to the holder seat 12 within the housing assembly 1 by means of, but is not limited to, a welded or screwed connection to provide additional structural support and protection against vibration.

[0061] As in Fig. 7, in one embodiment, the cell holder 24 has a limiting portion 245 that cooperates with the holder seat 12, the limiting portion 245 having a locking element, the locking element being in a form that includes, but is not limited to, a structural locking form, the locking element being a screw hole, or being screwed in place by a screw, or the locking element being a first mortise and tenon structure and being attached to the housing assembly 1 by a second mortise and tenon structure by means of snapping in, or by welding the limiting portion 245 to the housing assembly 1, or by locking by gluing or other methods to ensure that the cell holder 24 does not move in the housing assembly 1.

[0062] The cell holder 24 is fixedly connected to the holder seat 12 within the housing assembly 1 by, but not limited to, welding or screwing to provide additional structural support and vibration protection.

[0063] The pole piece holder 3 has as in Fig. 1 and Fig. 3 is shown via a terminal assembly 32 and a terminal mounting seat 33, wherein the terminal assembly 32 is arranged in the terminal mounting seat 33, wherein the terminal mounting seat 33 defines the terminal assembly 32, wherein the terminal mounting seat 33 is fixedly connected to the control board, wherein the terminal assembly 32 is connected to the control device 4, wherein the terminal mounting seat 33 has an insertion slot 331, wherein the insertion slot 331 serves to guide the correct insertion direction of the tool pole piece to avoid installation errors leading to a short circuit, and at the same time can stabilize the tool pole piece to ensure that it is effectively connected to the control device 4.

[0064] The control device 4 is as in Fig. 3 is provided on the cell holder 24, wherein the control device 4 comprises a control board 41 and a connecting element 42, wherein the control board comprises at least a control module and a communication module, wherein the control board 41 connects the unit cell 23 from the exposed hole 242 by means of the connecting element 42 to achieve at least the communication and control functions, wherein the control module serves to regulate parameters such as the voltage, the current and the temperature in the tool battery pack to ensure the safe and efficient operation of the entire system, wherein the communication module serves to exchange data with an external device to realize the monitoring of the operating state of the tool battery pack.

[0065] As in Fig. As shown in Figure 7, in one embodiment, the barrier element 5 is arranged on the cell assembly end face 211 by the positioning connector 57. The shape of the positioning connector 57 includes, but is not limited to, the positioning element as a positioning post or positioning hole, or the positioning form of a concavo-convex structure, etc., arranged on the barrier element 5 and / or the cell holder 24, connected to the cell assembly 2 by welding, screwing, gluing, snapping, etc. The barrier element 5 is connected to the cell assembly 2 in the form of an end fit; or connected to the housing assembly 1 by welding, screwing, snapping, gluing, etc., and connected to the housing assembly 1 in the form of an end fit.The positioning connector enables a final fit between the barrier element 5 with the cell assembly 2 or the housing assembly 1, which can prevent relative movement between the components, increase the stability of the entire battery pack structure, and reduce the risk of displacement or detachment due to vibration or shock.

[0066] A tool battery pack further comprises a barrier element 5 with a thermally conductive effect, wherein the barrier element is arranged on a cell assembly end face by means of a positioning connector, wherein the cell assembly end face serves as a reference plane, wherein the thermal conduction effect system refers to the thermal conductivity of a material under steady-state heat transfer conditions. Its technical properties are that the thermal conductivity value is ≥5 W / (m K), wherein the barrier element 5 is arranged on a cell assembly end face by means of a positioning connector 57, wherein the cell assembly end face is as in Fig. 4 serves as a reference plane, wherein the barrier element 5 has a first end surface 51 close to the reference plane and a second end surface 52 remote from the reference plane, wherein a distance G1 exists between the first end surface 51 and the cell assembly end surface, wherein a pressure relief space 53 is formed between the first end surface 51 and the cell assembly end surface, wherein the pressure relief space has at least one pressure relief outlet 55. Due to the mating structure of the receiving slot 241 and the exposed hole 242, each unit cell 23 forms a separate air chamber. With the compartmentalization effect of the barrier element 5, the range of influence of the thermal runaway of the unit cell can be limited within the two adjacent unit cells.The pressure relief space formed between the barrier element 5 and the cell assembly end face, together with the design of the pressure relief outlets, establishes a directional pressure relief mechanism and can directly guide high-temperature gases and flames generated by thermal runaway to a predetermined safe area, effectively reducing the risk of internal pressure buildup. At the same time, a dual role of barrier and protection is performed, and the barrier element 5 with thermal conductivity can be used as a physical barrier to prevent the flame from directly propagating to the housing and / or adjacent cells.The local high temperature can also be quickly distributed to the entire heat dissipation system of the battery pack through the thermal conductivity characteristics, so that the gaseous flame is extinguished due to the cooling effect of the metal surface in the gap, and the solid melt is blocked in the pressure relief space to avoid splashing to adjacent cells, so that the probability of fire, explosion and other accidents of the entire battery pack in the event of thermal runaway of the unit cell can be greatly reduced, and the overall reliability and safety of the battery can be improved.

[0067] As in Fig. As shown in Figure 4, in one embodiment, the distance between the first end surface 51 and the positive terminal end surface 23111 or the cap end surface 231111 or the negative terminal end surface 23112 of the cell assembly end surface is the distance G1. The distance G1 is greater than or equal to 1 mm and less than 10 mm. By establishing a pressure relief space at a distance of G1, a buffer zone can be effectively established in the assembly opposite the cell assembly end surface. Limiting the heat dissipation capacity of the cell from thermal runaway in the entire tool battery pack is an important factor in ensuring the safety of the tool battery pack.By precisely controlling the gap distance G1 according to this program, the initial heat wave can be blocked and directed toward a specific pressure relief space, effectively limiting the heat wave in the thermally burned unit cell and thermal propagation in all four directions to the adjacent unit cell 23 and / or the housing assembly 1. This effectively delays or prevents thermal runaway from being transmitted from one cell to the entire tool battery pack. It also ensures that the overall size of the tool battery pack does not become excessively large, allowing the tool battery pack design to be applied to existing tools and equipment while maintaining safety and performance.A standardized gap size makes the system easier and more efficient to operate during the production and assembly process.

[0068] As in Fig. 8-9, the barrier element 5 is shown in one embodiment as a groove-shaped barrier element or a flat plate-shaped barrier element, wherein the barrier element 5 forms a pressure relief space with all cell assembly end surfaces, wherein the pressure relief space has at least one pressure relief outlet 55, wherein the pressure relief outlet 55 can be provided on the barrier element 5 and / or the cell assembly end surface and / or the cell holder 24, wherein the pressure relief outlet 55 is provided on the side surface of the pressure relief space, wherein the pressure relief outlet 55 is not provided parallel to the cell end surface of the cell assembly end surface, wherein the barrier element 5 is constructed in a groove-shaped or plate-shaped manner, which can reduce the complexity and costs of manufacturing and can simplify the manufacturing and assembly between cell assemblies, which contributes toto assemble everything quickly and form an effective pressure relief space. The provision of the pressure relief outlet 55 provides a clear pressure relief path for the pressure relief space, effectively preventing the accumulation of excessive pressure in the cell assembly 2 and reducing the risk of damage to other unit cells 23 adjacent to the thermally passable unit cell 23. The pressure relief outlet 55 can be provided on the barrier element 5 and / or the cell assembly end face and / or the cell holder 24, offering a variety of options for the pressure relief path. By arranging the pressure relief outlet on various components, it can be flexibly adapted to the specific design and thermal management requirements of the tool battery pack, optimizing the pressure relief effect, reducing internal pressure accumulation, and also contributing toMaintain the physical integrity and stability of the tool battery pack, avoid physical damage and potential safety accidents caused by excessive pressure, and cooperate with groove-shaped or flat barrier elements. 5. The pressure relief chamber can not only contribute to pressure relief but also, to a certain extent, assists in the dissipation of heat waves and further slows the uncontrolled spread of heat.

[0069] In one embodiment, the barrier element 5 is a groove-shaped barrier element or a flat plate-shaped barrier element, wherein the barrier element 5 forms a pressure relief space with all cell assembly end surfaces, wherein the pressure relief space has at least one pressure relief outlet 55, wherein the pressure relief outlet 55 is provided on the barrier element 5 and is located in the area (no cell end surface 231) between the unit cell 23 and the unit cell 23, wherein the pressure relief outlet 55 is parallel to the cell end surface of the cell assembly end surface, wherein the barrier element 5 is constructed in a groove-shaped or plate-shaped manner, which can reduce the complexity and cost of manufacturing and can simplify the manufacturing and assembly between cell assemblies, which contributes to rapid assembly and forming an effective pressure relief space.The pressure relief outlet 55 is provided on the barrier element 5 and is located in the area (not the cell end face) between the unit cells. The arrangement parallel to the cell assembly end face ensures the directness and smoothness of the pressure relief path.

[0070] When thermal runaway occurs, the pressure relief space allows the internal pressure of the thermally runaway unit cell to be quickly and efficiently released directly along the cell's internal pressure relief path parallel to the cell assembly end face, quickly mitigating the effects of local temperature rise and preventing rapid heat buildup.

[0071] In one embodiment, the projection area of ​​the end face of the barrier element 5 is larger than the maximum projection area of ​​the adjacent cell assembly end face and can completely cover the maximum projection area of ​​the adjacent cell assembly end face. Because the barrier element 5 is larger than the maximum projection area of ​​the adjacent cell assembly end face, the barrier element 5 can completely cover the maximum projection area of ​​the cell assembly end face, allowing for better control and management of the heat diffusion path. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events.

[0072] In one embodiment, the projection area of ​​the end face of the barrier element 5 is smaller than the projection area of ​​the adjacent cell assembly end face. The maximum projection area of ​​the barrier element 5 is greater than or equal to the projection area of ​​the maximum outer size of all adjacent cell end faces of the cell assembly end face. The barrier element 5 can completely cover the maximum projection area of ​​the cell assembly end face, so that the heat diffusion path can be better controlled and managed. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway transmission, and can fully protect the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0073] In one embodiment, the barrier element 5 is assembled in one piece or split. The one-piece barrier element 5 has good structural integrity and reduces potential connection weaknesses in the split structure. Since there are no additional splicing and bonding points, its overall strength is higher and it can better withstand external shocks and pressures, thereby improving the durability and stability of the tool battery pack. Split assembly allows the design and material selection of each component to be customized to specific needs. This flexibility allows for better adaptation to the design requirements and size changes of different tool battery packs. If a specific part is damaged, the separately assembled barrier elements can be more easily replaced and repaired in the field without having to replace the entire component, reducing maintenance costs and time.

[0074] In one embodiment, the unit cell 23 has a cell end face 231 and a cell main body 232, and the thickness J of the barrier element 5 corresponding to the cell end face region is greater than or equal to 0.8 mm and less than or equal to 3 mm. It can provide sufficient space for pressure relief while maintaining structural strength when the thickness J of the barrier element is in a range greater than or equal to 0.8 mm and less than or equal to 3 mm. This thickness contributes to effectively conducting and releasing pressure under extreme conditions (e.g., thermal runaway).The thickness range is also sufficient to provide effective thermal insulation and slow heat conduction from one cell to neighboring cells, increasing the safety of the battery system and ensuring that the barrier element does not add excessive weight or take up too much space while providing support and insulation, ensuring overall low weight and compactness of the tool battery pack.

[0075] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least 2 cell end faces 231, wherein the thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element 5 corresponding to the area of ​​the first cell end face 2311 and the second cell end face 2312 is regulated to be the same for ease of manufacture.

[0076] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least 2 cell end faces 231, wherein the thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element 5 corresponding to the area of ​​the first cell end face 2311 is less than or equal to 1 mm when subtracted from the thickness of the barrier element 5 corresponding to the area of ​​the second cell end face 2312.By controlling the thickness difference between the barrier elements 5 corresponding to the first cell end face 2311 and the second cell end face 2312, the thicker barrier element 5 in the high-frequency thermal runaway region has a higher local heat capacity due to more materials, which can absorb more heat and slow the temperature rise rate; at the same time, its thermal conductivity path can quickly conduct heat to the heat dissipation structure of the package assembly 1 to avoid heat buildup. The thinner barrier element 5 in the low-frequency region prioritizes ensuring heat dissipation efficiency and prevents abnormal local temperature rise due to rapid thermal conductivity. This achieves a differentiated response of the pressure relief space.

[0077] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least two cell end faces 231, wherein the thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element 5 corresponding to the area of ​​the first cell end face 2311 is greater than the thickness of the barrier element 5 corresponding to the area of ​​the second cell end face 2312. Barrier elements of different thicknesses can provide tailored solutions for the specific thermal management requirements of each cell. For example, the first cell end face 2311 is located at the location where high-frequency thermal runaway occurs and high-temperature and high-pressure gases are exhausted.The thickness of the barrier element 5 here is relatively thick, forming a relatively small pressure relief space, which can provide greater resistance to the high-pressure gas escaping in the early stages of thermal runaway, slow the gas flow rate, and reduce the immediate impact on the pressure relief outlet. The second cell end face 2312 is located at the location where low-frequency and high-frequency thermal runaway occur and high-temperature and high-pressure gases are discharged. The thickness of the barrier plate 5 here is relatively thick, forming a relatively large pressure relief space, which can accommodate more gas expansion, buffer pressure fluctuations, and realize a differentiated response to the pressure relief space.

[0078] In an embodiment as in C-1 of the Fig. 10, the end face of the adjacent cell assembly end face is used as the reference plane, and the barrier member 5 has a first end face 51 close to the reference plane and a second end face 52 away from the reference plane. The first end face 51, corresponding to the cell end face 231, has a convex structure away from the reference plane, and the maximum outer size of the convex structure is greater than or equal to the cell end face 231. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier member 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging the gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure.At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection. The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0079] In an embodiment as in C-2 of the Fig. 10, the end face of the adjacent cell assembly end face is used as the reference plane, and the barrier member 5 has a first end face 51 close to the reference plane and a second end face 52 away from the reference plane. The first end face 51, corresponding to the cell end face 231, has a convex structure away from the reference plane, and the maximum outer size of the convex structure is smaller than the cell end face 231. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier member 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging the gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure.At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection. The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0080] In an embodiment as in D-1 of the Fig. 11, the end surface of the adjacent cell assembly end surface is used as the reference plane, and the barrier member 5 has a first end surface 51 close to the reference plane and a second end surface 52 away from the reference plane. The first end surface 51, corresponding to the cell end surface 231, has a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end surface and the end surface of the barrier member 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging the gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively by natural convection. The cell generates heat during the charging and discharging process.A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0081] In an embodiment as in D-2 of the Fig. 11, the end surface of the adjacent cell assembly end surface is used as the reference plane, and the barrier element 5 has a first end surface 51 close to the reference plane and a second end surface 52 away from the reference plane. The first end surface 51 and the second end surface 52, which correspond to the cell end surface 231, have a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end surface and the end surface of the barrier element 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and dissipating the gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection.The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0082] As in D-3 of the Fig. 11, in one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, wherein the barrier element 5 has a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane, wherein the first end face 51 and the second end face 52 are both planar.

[0083] In one embodiment, the barrier element 5 is a thermally conductive material with an ignition point of ≥300°C. A material with an ignition point of ≥300°C is used to ensure that the barrier element maintains structural integrity in a high-temperature environment or in the event of a thermal runaway of the cell, which is not easily burned or decomposed, and improves the safety of the battery system. Using thermally conductive materials, the barrier element 5 can effectively conduct heat quickly from the battery cell and help equalize the temperature between the cells, prevent the occurrence of local overheating, and avoid excessive temperature rises caused by heat accumulation inside the battery through good thermal conduction properties, which helps reduce the risk of thermal runaway.

[0084] In one embodiment, the barrier element 5 is made of a rigid material with a flash point of ≥ 300°C or higher. Using a material with a flash point of ≥ 300°C ensures that the barrier element maintains its structural integrity in a high-temperature environment or in the event of a thermal runaway of the cell, so that it does not easily burn or decompose, and improves the safety of the battery system. Furthermore, the rigid material provides better resistance to thermal conduction, effectively preventing the transmission of flames or high temperatures to the adjacent cell and reducing the risk of a propagating thermal runaway. Under extreme conditions, the material can act as a flame barrier to protect the internal cells from the outside world or other heat sources that may be generated by the cells.

[0085] In one embodiment, the barrier element 5 is a thermally conductive material with a thermal conductivity value ≥5 W / (m K). Using a thermally conductive material with a thermal conductivity value ≥5 W / (m K), the barrier element 5 can effectively conduct heat quickly from the battery cell and help equalize the temperature between the cells, prevent the occurrence of local overheating, and, through good thermal conduction properties, prevent the temperature rise caused by the accumulation of heat inside the battery from being excessive, thus helping to reduce the risk of thermal runaway.

[0086] In one embodiment, the barrier element is a metallic material, and the gap G1 is greater than or equal to 1 mm and less than 10 mm. The metal barrier element forms a non-contact thermal conductivity channel with the cell end face through the gap G1, which can quickly dissipate local high-temperature heat laterally toward the cooling surface of the housing during thermal runaway.

[0087] In one embodiment, the pressure relief airflow from the pressure relief outlet 55 is discharged through the second cooling opening 14. During thermal runaway, the high-temperature and / or high-pressure gas from the pressure relief outlet 55 is directed through the second heat dissipation opening 14 (air outlet), so that the pressure relief airflow and the heat dissipation airflow at the outlet form a superposition effect in the same direction, accelerating the hazardous gas away from the core area of ​​the battery pack and preventing internal gas retention.

[0088] In one embodiment, the pressure relief air flow from the pressure relief outlet flows through the second cooling opening 14, and the material of the second cooling opening is plastic.

[0089] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling hole 14, and the material of the second cooling hole is metal. When the high-temperature gas flows through the metal cooling hole, the heat is quickly transferred through the metal surface to the battery pack casing or the external environment, thereby lowering the temperature of the discharged gas and reducing thermal damage to peripheral components. The metal cooling hole serves as an additional heat dissipation channel and cooperates with the thermal conductivity path of the barrier element to accelerate overall heat dissipation in the battery pack.

[0090] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling port 14. The second cooling port has a pressure relief valve that serves as a conventional cooling channel to help the device maintain normal operating temperature. If the pressure is too high, the pressure relief valve is activated to release the airflow through this port and achieve pressure relief. Fig. 14 - Fig. 16 is a view of the structure of the tool battery pack provided by an embodiment of the present application.

[0091] An example of the tool battery pack

[0092] A tool battery pack is provided with a housing assembly 1, a cell assembly 2, a pole piece holder 3 and a control device 4;

[0093] The housing assembly 1 has a holder seat (not shown), an opening 13 used to receive the cell assembly, the pole piece holder, and the control device; the opening 13 is arranged corresponding to the location of the pole piece holder 3 in the housing assembly 1 so that the tool pole piece penetrates it and connects to the pole piece holder 3; the holder seat (not shown) is provided on at least one side within the housing assembly 1 to fix the electrical cell assembly 2.

[0094] As in Fig. 14-16, the cell assembly 2 comprises a first cell assembly 21, a second cell assembly 22, a unit cell 23, a cell holder 24 and a cell assembly connector 27.

[0095] The first cell assembly 21 includes a first cell assembly end face 211 and a second cell assembly end face 212, wherein the second cell assembly 22 includes a third cell assembly end face 221 and a fourth cell assembly end face 222, wherein the third cell assembly end face 221 is opposite the second cell assembly end face 212; The first cell assembly 21 and the second cell assembly are connected by a cell assembly connector 27, wherein all cell assembly end faces include at least cell holder end faces and all cell end faces 231, wherein all cell assembly connectors 27 include, but are not limited to, connecting posts. The two sets of cell assemblies are attached in the form of screwing and gluing, and may also be interlocked, e.g., gears and tooth limit position, etc.

[0096] As in Fig. 6, the unit cell 23 is a cylindrical cell having a cell end face 231 and a cell main body 232, wherein the cell end face 231 is provided with a first cell end face 2311 and a second cell end face 2312.

[0097] In one embodiment, the first cell end surface 2311 has a positive pole end surface 23111 and the positive pole end surface 23111 is a flat end surface, wherein the second cell end surface 2312 is a negative pole end surface.

[0098] In one embodiment, the first cell end face 2311 has a positive pole end face 23111 and the positive pole end face 23111 has a cap end face 231111, the cap end face 231111 protruding outwardly from the positive pole end face 23111, the second cell end face 2312 being a negative pole end face.

[0099] In one embodiment, the first cell end face 2311 includes a positive terminal end face 23111 and also a negative terminal end face 23112. A separator 23113 is provided between the negative terminal end face 23112 and the positive terminal end face 23111 to isolate the positive electrode from the negative electrode to prevent short circuiting. The second cell end face 2312 is a negative terminal end face, with the edge of the negative terminal end face 23112 near the central axis of the unit cell 23 being the first edge, with the exposed hole 242 exposing the first edge, and the projection distance C between the first edge and the edge within the exposed hole 242 being greater than or equal to 0.1 mm. With a distance between the exposed hole 242 and the first edge, not only is the electrical insulation structurally improved, but also the waterproofing layer 25 is allowed to cover the negative terminal end face 23112 and the separator 23113.Once the separator 23113 breaks or fails due to aging, the waterproofing layer 25 becomes an additional barrier layer that prevents water vapor from penetrating the cell. At the same time, the waterproofing layer 25 covers the negative terminal end face 23112 and the exposed hole 242, preventing water vapor from penetrating the cell end face along its length from the mounting gaps of the receiving slot 241 and further from coming into contact with the positive terminal end face and negative terminal end face 23112, thus preventing a potential short circuit.

[0100] Each group of cell assembly end faces comprises at least 2 cell end faces 231.

[0101] As in Fig. 5, the cell holder 24 has a receiving slot 241, an exposed hole 242, a first end 243, a second end 244, wherein the first end 243 of the cell holder 24 has a receiving slot 241 that receives the unit cell 23, wherein one end of the receiving slot 241 has a groove into which the unit cell 23 projects, wherein the other end of the receiving slot 241 has an exposed hole 242 that extends through the cell holder 24, wherein the exposed hole 242 is arranged at the second end 244, wherein the area within the hole is smaller than the cross-sectional area of ​​the receiving slot 241, which is parallel to the exposed hole 242, wherein the area of ​​the exposed hole 242 is smaller than the maximum area of ​​the first cell end surface that extends into the receiving slot 241, wherein the exposed hole 242 for Exposing the partial cell end surfaces, wherein the shape of the exposed hole 242 is a rounded shape, an oval shape,includes, but is not limited to, a square shape and other shapes; wherein the cell holder 24 is securely attached to the holder seat 12 within the housing assembly 1 by means of, but is not limited to, a welded or screwed connection to provide additional structural support and protection against vibrations.

[0102] As in Fig. 7, in one embodiment, the cell holder 24 has a limiting portion 245 that cooperates with the holder seat 12, the limiting portion 245 having a locking element, the locking element being in a form that includes, but is not limited to, a structural locking form, the locking element being a screw hole, or being screwed in place by a screw, or the locking element being a first mortise and tenon structure and being attached to the housing assembly 1 by a second mortise and tenon structure by means of snapping in, or by welding the limiting portion 245 to the housing assembly 1, or by locking by gluing or other methods to ensure that the cell holder 24 does not move in the housing assembly 1.

[0103] In one embodiment, the hole height d of the exposed hole 242 is greater than or equal to 0.5 mm and less than or equal to 2.5 mm. By setting the hole height d of the exposed hole 242 to greater than or equal to 0.5 mm, an effective support strength for the unit cell 23 can be achieved, preventing the position of the unit cell 23 from shifting due to vibration or other external forces during normal use, thus improving the overall mechanical stability and safety of the tool battery pack. Because it is less than or equal to 2.5 mm, the use of unnecessary materials can be avoided while enhancing stability, thereby optimizing the weight of the tool battery pack and further improving energy efficiency and endurance performance. When designing the height range, the utilization rate of the cell's internal space is also taken into account.On the basis of ensuring strong support, reasonable adjustment of the height within the hole avoids unnecessary occupation of the effective space of the tool battery pack, so that the battery pack can maximize the capacity and energy density within the limited space.

[0104] The cell holder 24 is securely attached to the holder seat 12 within the housing assembly 1 by means of, but not limited to, a welded or bolted connection to provide additional structural support and protection against vibrations; wherein cell holders 24 are provided on both cell end faces of the unit cell 23, wherein the cell holder 24 has a receiving slot 241 which receives the unit cell 23, wherein the first end 2411 of the receiving slot 241 has a groove into which the unit cell 23 projects, wherein the second end 2412 of the receiving slot 241 has an exposed hole 242 which extends through the cell holder 24, wherein the area within the exposed hole 242 is smaller than the cross-sectional area of ​​the receiving slot 241 which is parallel to the exposed hole 242, wherein the area of ​​the exposed hole 242 is smaller than the maximum area of ​​the cell end face which extends into the receiving slot 241.

[0105] The pole piece holder 3 has a terminal assembly 32 and a terminal fixing seat 33, the terminal assembly 32 being fitted into the terminal fixing seat 33, the terminal fixing seat 33 defining the terminal assembly 32, the terminal fixing seat 33 being fixedly connected to the control board, the terminal assembly 32 being connected to the control device 4, the terminal fixing seat 33 having an insertion slot 331, the insertion slot 331 serving to guide the correct insertion direction of the tool pole piece to avoid installation errors resulting in a short circuit, and at the same time can stabilize the tool pole piece to ensure that it is effectively connected to the control device 4.

[0106] The control device 4 is provided on the cell holder 22, the control device 4 having a control board 41 and a connector 42, the control board having at least a control module and a communication module, the control board 41 connecting the unit cell 23 from the exposed hole 242 through the connector 42 to achieve at least the communication and control functions, the control module serving to regulate parameters such as the voltage, the current and the temperature in the tool battery pack to ensure the safe and efficient operation of the entire system, the communication module serving to exchange data with an external device to realize the monitoring of the operating state of the tool battery pack.

[0107] In an embodiment as in Fig. 15, the barrier element 5 is arranged between the third cell assembly end surface 221 and the second cell assembly end surface 212, wherein the third cell assembly end surface 221 serves as a reference plane, wherein the barrier element 5 has a first end surface 51 close to the reference plane and a second end surface 52 remote from the reference plane, wherein a first pressure relief space 55A exists between the first end surface 51 and the third cell assembly end surface 221, wherein a distance G1 exists between the first end surface 51 and the third cell assembly end surface 221, wherein a second pressure relief space 55B exists between the second end surface 52 and the second cell assembly end surface 212, wherein a distance G2 exists between the second end surface 52 and the second cell assembly end surface 212, wherein the first pressure relief space 55A and the second pressure relief space 55B have at least one pressure relief outlet 55.Compared to existing tool battery packs that are not configured with a barrier element, when the unit cell is in thermal runaway, it is not possible to achieve thermal diffusion of high-temperature gases and flames escaping from the cell end face toward the housing assembly 1 and / or the cell assembly 2, causing it to rupture and destroy. In this application, the barrier element is disposed between the third cell assembly end face 221 and the second cell assembly end face 212, thus introducing a relatively self-contained pressure relief space between adjacent cell assemblies to form a physical barrier. Through the mating structure of the receiving slot 241 and the exposed hole 242, each unit cell 23 in this application forms a separate air chamber.With the compartmental isolation effect of the barrier element 5, the impact area of ​​thermal runaway of the unit cell can be limited within the two adjacent unit cells. The pressure relief space formed between the barrier element 5 and the cell assembly end face, together with the design of the pressure relief outlets, establishes a directional pressure relief mechanism and can directly guide high-temperature gases and flames generated by thermal runaway to a predetermined safe area, effectively reducing the risk of internal pressure buildup. This significantly reduces the likelihood of fires, explosions, and other accidents in the entire battery pack in the event of a unit cell thermal runaway, and improves the overall reliability and safety of the battery.

[0108] As in B-1 of the Fig. 14, in one embodiment, the third cell assembly end face 221 has a first cell end face 2311. When the cell end face of the second cell end face 212 that is opposite the first cell end face 2311 of the third cell assembly end face 221 is the first cell end face 2311 (it is understood that for two cell assemblies, one of the two adjacent sets of cell assembly end faces is the positive terminal and the opposite cell end face is also a positive terminal.), the distance between the second end surface 52 and the positive pole end surface 23111 or the cap end surface 231111 or the negative pole end surface 23112 of the third cell assembly end surface 221 is the distance G1, wherein the distance G1 is greater than or equal to 1 mm and less than 10 mm; wherein the distance between the first end surface 51 and the positive pole end surface 23111 or the cap end surface 231111 or the negative pole end surface 23112 of the second cell assembly end surface 212 is the distance G2, wherein the distance G2 is greater than or equal to 1 mm and less than 10 mm. By establishing a pressure relief space at a distance between G1 and G2, a buffer zone can be effectively established in the assembly opposite to the cell assembly end face. Limiting the heat dissipation capacity of the cell from thermal runaway in the entire tool battery pack is an important factor to ensure the safety of the tool battery pack.By precisely controlling the gap (distance G1, distance G2), the initial heat wave can be blocked according to this program and the heat wave is directed toward a specific space for pressure relief, effectively limiting the heat wave in the thermally burned unit cell and the thermal propagation in all four directions of the adjacent unit cell. This effectively delays or prevents thermal runaway from being transmitted from one cell to the entire tool battery pack. It also ensures that the overall size of the tool battery pack does not become too large, so that the tool battery pack design can still be applied to existing tools and equipment while maintaining safety and performance. A standardized gap size makes the system simpler and more efficient in terms of operation during production and assembly.

[0109] As in B-2 of the Fig. 14, in one embodiment, the third cell assembly end face 221 has a first cell end face 2311. When the cell end face of the second cell end face 212 that is opposite to the first cell end face 2311 of the third cell assembly end face 221 is the second cell end face 2312 (It is understood that for two cell assemblies, one of the two adjacent sets of cell assembly end faces is the negative terminal and the opposite cell end face is also a negative terminal), the distance between the second end face 52 and the positive terminal end face 23111 or the cap end face 231111 or the negative terminal end face 23112 of the third cell assembly end face 221 is the distance G1, where the distance G1 is greater than or equal to 1 mm and less than 10 mm; wherein the distance between the first end surface 51 and the second cell end surface 2312 of the second cell assembly end surface 212 is the distance G2, wherein the distance G2 is greater than or equal to 1 mm and less than 10 mm.By establishing a pressure relief space at a distance of G1 and G2, a buffer zone can be effectively established in the assembly opposite the cell assembly end face. Limiting the heat dissipation capacity of the cell from thermal runaway throughout the entire tool battery pack is an important factor in ensuring the safety of the tool battery pack. By precisely controlling the gap (distance G1, distance G2), the initial heat wave can be blocked according to this program and the heat wave is guided toward a specific pressure relief space, which effectively limits the heat wave in the thermally burned unit cell with the thermal propagation in all four directions of the neighboring unit cell. This achieves a certain degree of delaying or preventing thermal runaway from being transmitted from one cell to the entire tool battery pack.It also ensures that the overall size of the tool battery pack isn't too large, allowing the tool battery pack design to be applied to existing tools and equipment while maintaining safety and performance. A standardized gap size makes the system simpler and more efficient to operate during production and assembly.

[0110] As in B-3 of the Fig. 14, in one embodiment, the third cell assembly end face 221 has a second cell end face 2312. When the cell end face of the second cell end face 212 that is opposite the first cell end face 2311 of the third cell assembly end face 221 is the second cell end face 2312 (It is understood that for two cell assemblies, one of the two adjacent sets of cell assembly end faces is the positive terminal and the opposite cell end face is also a negative terminal), the distance between the second end face 52 and the second cell end face 2312 of the third cell assembly end face 221 is the distance G1, where the distance G1 is greater than or equal to 1 mm and less than 10 mm; where the distance between the first end face 51 and the second cell end face 2312 of the second cell assembly end face 212 is the distance G2, where the distance G2 is greater than or equal to 1 mm and less than 10 mm.By establishing a pressure relief space at a distance of G1 and G2, a buffer zone can be effectively established in the assembly opposite the cell assembly end face. Limiting the heat dissipation capacity of the cell from thermal runaway throughout the entire tool battery pack is an important factor in ensuring the safety of the tool battery pack. By precisely controlling the gap (distance G1, distance G2), the initial heat wave can be blocked according to this program and the heat wave is guided toward a specific pressure relief space, which effectively limits the heat wave in the thermally burned unit cell with the thermal propagation in all four directions of the neighboring unit cell. This achieves a certain degree of delaying or preventing thermal runaway from being transmitted from one cell to the entire tool battery pack.It also ensures that the overall size of the tool battery pack isn't too large, allowing the tool battery pack design to be applied to existing tools and equipment while maintaining safety and performance. A standardized gap size makes the system simpler and more efficient to operate during production and assembly.

[0111] In one embodiment, the distance G1 and the distance G2 are equal. Because the distance G1 and the distance G2 are equal, the compensation interval is in the early stage of thermal runaway. The symmetrical distance G1 / G2 causes the high-temperature gas to be discharged from the first space and the second pressure relief space in parallel at the same flow rate, avoiding local air turbulence caused by uneven pressure relief and reducing the risk of heat wave superposition. The equidistant design of the double pressure relief space forms a pressure relief compensation mechanism in both directions.If abnormal gas production occurs on one side of the cell assembly, the symmetrical channel can automatically equalize the pressure difference on both sides, preventing structural deformation caused by overstress on one side and simultaneously suppressing a chain reaction of thermal runaway. The balanced pressure relief channel allows heat to be evenly distributed along the axial direction of the battery pack. Combined with the high-temperature resistance properties of the barrier element, the problem of thermal stress concentration between cells is significantly reduced.

[0112] In one embodiment, the difference between the distance G1 and the distance G2 is less than or equal to 3 mm, and the ΔG difference constructs an asymmetric heat conduction path, which enables differentiated management of heat propagation in the space, increasing the gap in high-risk areas such as the positive terminal cell end face and narrowing the gap in the negative terminal cell end face in low-risk areas, thereby making heat management more flexible and efficient. Through detailed space management, the safety performance of the tool battery pack during thermal runaway is optimized while ensuring its compactness and applicability. This design enhances the practical application effect of the tool battery pack.

[0113] A positioning connector 57 is arranged on the barrier element 5. The shape of the positioning connector 57 includes, but is not limited to, the positioning element as a positioning post or positioning hole, or the positioning form of a concave-convex structure, etc., arranged on the barrier element 5, connected to the cell assembly 2 by welding, screwing, gluing, snapping, etc. The barrier element 5 is connected to the cell assembly 2 in the form of an end fit; or connected to the housing assembly 1 by welding, screwing, snapping, gluing, etc., and connected to the housing assembly 1 in the form of an end fit.The positioning connector enables a final fit between the barrier element 5 with the cell assembly 2 or the housing assembly 1, which can prevent relative movement between the components, increase the stability of the entire battery pack structure, and reduce the risk of displacement or detachment due to vibration or shock.

[0114] The barrier element 5 is, in one embodiment, a groove-shaped barrier element or a flat plate-shaped barrier element, wherein the barrier element 5 forms a pressure relief space with all cell assembly end surfaces, wherein the pressure relief outlet 55 can be provided on the barrier element 5 and / or the cell assembly end surface and / or the cell holder 24, wherein the pressure relief outlet 55 is provided on the side surface of the pressure relief space, wherein the pressure relief outlet 55 is perpendicular to the cell end surface of the cell assembly end surface, wherein the barrier element 5 is constructed in a groove-shaped or plate-shaped manner, which can reduce the complexity and cost of manufacturing and can simplify the manufacturing and assembly between cell assemblies, which contributes to rapid assembly and forming an effective pressure relief space.The provision of the pressure relief outlet 55 provides a clear pressure relief path for the pressure relief chamber, effectively preventing the accumulation of excessive pressure in the cell assembly 2, thereby reducing the risk of damage to other unit cells 23 adjacent to the thermally permeable unit cell 23. The pressure relief outlet 55 can be provided on the barrier element 5 and / or the cell assembly end face 231 and / or the cell holder 24, offering a variety of options for the pressure relief path.By arranging the pressure relief outlet on various components, it can be flexibly adapted to the specific design and thermal management requirements of the tool battery pack, optimize the pressure relief effect, reduce internal pressure accumulation, and also help maintain the physical integrity and stability of the tool battery pack, prevent physical damage and potential safety accidents caused by excessive pressure, and cooperate with groove-shaped or flat barrier elements 5. The pressure relief space can not only contribute to pressure relief, but also assists in the dissipation of heat waves to a certain extent and further slows down the uncontrolled spread of heat.

[0115] In one embodiment, the barrier element 5 is a groove-shaped barrier element or a flat plate-shaped barrier element, wherein the barrier element 5 forms a pressure relief space with all cell assembly end surfaces, wherein the pressure relief space has at least one pressure relief outlet 55, wherein the pressure relief outlet 55 is provided on the barrier element 5 and is located in the area (no cell end surface 231) between the unit cell 23 and the unit cell 23, wherein the pressure relief outlet 55 is parallel to the cell end surface of the cell assembly end surface, wherein the barrier element 5 is constructed in a groove-shaped or plate-shaped manner, which can reduce the complexity and cost of manufacturing and can simplify the manufacturing and assembly between cell assemblies, which contributes to rapid assembly and forming an effective pressure relief space.The pressure relief outlet 55 is provided on the barrier element 5 and is located in the area (not the cell end face) between the unit cells. The arrangement parallel to the cell assembly end face ensures the directness and smoothness of the pressure relief path.

[0116] When thermal runaway occurs, the pressure relief space allows the internal pressure of the thermally runaway unit cell to be quickly and efficiently released directly along the cell's internal pressure relief path parallel to the cell assembly end face, quickly mitigating the effects of local temperature rise and preventing rapid heat buildup.

[0117] In one embodiment, the projection area of ​​the end face of the barrier element 5 is greater than or equal to the maximum projection area of ​​the adjacent cell assembly end face. Because the projection area of ​​the end face of the barrier element 5 is greater than the maximum projection area of ​​the adjacent cell assembly end face, the barrier element 5 can completely cover the maximum projection area of ​​the cell assembly end face, allowing the heat diffusion path to be better managed and controlled. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events.

[0118] In one embodiment, the projection area of ​​the end face of the barrier element 5 is smaller than the maximum projection area of ​​the adjacent cell assembly end face, and the barrier element 5 is located between adjacent cell assembly end faces. The projection area of ​​the maximum outer size of all cell end faces of the third cell assembly end face 221 is identical to the projection area of ​​the maximum outer size of all cell end faces of the second cell assembly end face 212. The projection area of ​​the barrier element 5 is greater than or equal to the projection area of ​​the maximum outer size of all cell end faces of the adjacent cell assembly end face and can completely cover them. The barrier element 5 can cover the maximum projection area of ​​the cell assembly end face, so that the heat diffusion path can be better managed and controlled.This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events and fully protecting the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0119] In one embodiment, the projection area of ​​the end face of the barrier element 5 is smaller than the projection area of ​​the adjacent cell assembly end face, and the barrier element 5 is located between adjacent cell assembly end faces. The projection area of ​​the maximum outer size of all cell end faces of the third cell assembly end face 221 is smaller than the projection area of ​​the maximum outer size of all cell end faces of the second cell assembly end face 212. The maximum projection area of ​​the barrier element 5 is greater than or equal to the projection area of ​​the maximum outer size of all cell end faces of the second cell assembly end face 212 and can completely cover them. The barrier element 5 can cover the maximum projection area of ​​the cell assembly end face, so that the heat diffusion path can be better managed and controlled.This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events and fully protecting the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0120] In one embodiment, the projection area of ​​the end face of the barrier element 5 is smaller than the projection area of ​​the adjacent cell assembly end face, and the barrier element 5 is located between adjacent cell assembly end faces. The maximum outer size of all cell end faces of the third cell assembly end face 221 is identical and corresponding to the maximum outer size of all cell end faces of the second cell assembly end face 212. The maximum projection area of ​​the barrier element 5 is greater than or equal to the maximum projection area of ​​all cell end faces of the adjacent cell assembly end face and can completely cover them. The barrier element 5 can cover the maximum projection area of ​​the cell assembly end face, so that the heat diffusion path can be better managed and controlled.This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway events and fully protecting the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0121] In one embodiment, the projection area of ​​the end face of the barrier element 5 is smaller than the projection area of ​​the adjacent cell assembly end face, and the barrier element 5 is located between adjacent cell assembly end faces. The maximum outer size of all cell end faces of the third cell assembly end face 221 is identical and not corresponding, or neither identical nor corresponding, to the maximum outer size of all cell end faces of the second cell assembly end face 212. The maximum projection area of ​​the barrier element 5 is greater than or equal to the maximum projection area resulting from a union of the maximum outer sizes of all cell end faces of the second cell assembly end faces 212 and the maximum outer sizes of all cell end faces of the third cell assembly end faces 221.The barrier element 5 can cover the maximum projection area of ​​the cell assembly end face, allowing the heat diffusion path to be better managed and controlled. This design limits direct heat transfer to the adjacent unit cell, effectively reducing the risk of thermal runaway transmission and can fully protect the cell's projection area. This limits effective heat transfer when the cell experiences thermal runaway. Furthermore, this design ensures effective protection of the cell assembly.

[0122] In one embodiment, the barrier element 5 is assembled in one piece or split. The one-piece barrier element 5 has good structural integrity and reduces potential connection weaknesses in the split structure. Since there are no additional splicing and bonding points, its overall strength is higher and it can better withstand external shocks and pressures, thereby improving the durability and stability of the tool battery pack. Split assembly allows the design and material selection of each component to be customized to specific needs. This flexibility allows for better adaptation to the design requirements and size changes of different tool battery packs. If a specific part is damaged, the separately assembled barrier elements can be more easily replaced and repaired in the field without having to replace the entire component, reducing maintenance costs and time.

[0123] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least two cell end faces 231, wherein the thickness J of the barrier element 5, corresponding to the area of ​​the cell end faces 231, is 0.8 mm~3 mm. It can provide sufficient space for pressure relief while maintaining structural strength if the thickness J of the barrier element is in the range between 0.8 mm~3 mm. This thickness contributes to effectively conducting and releasing pressure under extreme conditions (e.g., thermal runaway).The thickness range is also sufficient to provide effective thermal insulation and slow heat conduction from one cell to neighboring cells, increasing the safety of the battery system and ensuring that the barrier element does not add excessive weight or take up too much space while providing support and insulation, ensuring overall low weight and compactness of the tool battery pack.

[0124] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least 2 cell end faces 231, wherein the thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element 5 corresponding to the area of ​​the first cell end face 2311 is less than or equal to 1 mm when subtracted from the thickness of the barrier element 5 corresponding to the area of ​​the second cell end face 2312.The thicker barrier element 5 in the high-frequency thermal runaway region has a higher local heat capacity due to more materials, which can absorb more heat and slow the temperature rise rate. At the same time, its thermal conductivity path can quickly conduct heat to the heat dissipation structure of the housing assembly 1 to avoid heat buildup. The thinner barrier element 5 in the low-frequency region prioritizes ensuring heat dissipation efficiency and prevents abnormal local temperature rise due to rapid thermal conductivity. This achieves a differentiated response of the pressure relief chamber.

[0125] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least two cell end faces 231, wherein the thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element 5 corresponding to the area of ​​the first cell end face 2311 is greater than the thickness of the barrier element 5 corresponding to the second cell end face 2312. The first cell end face 2311 is located at the location where high-frequency thermal runaway occurs and high-temperature and high-pressure gases are exhausted.The thickness of the barrier element 5 here is relatively thick, forming a relatively small pressure relief space, which can provide greater resistance to the high-pressure gas escaping in the early stages of thermal runaway, slow the gas flow rate, and reduce the immediate impact on the pressure relief outlet. The second cell end face 2312 is located at the location where low-frequency and high-frequency thermal runaway occur and high-temperature and high-pressure gases are discharged. The thickness of the barrier element 5 here is relatively thick, forming a relatively large pressure relief space, which can accommodate more gas expansion, buffer pressure fluctuations, and realize a differentiated response to the pressure relief space.

[0126] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least two cell end faces 231. The thickness J of the barrier element 5 corresponding to the area of ​​the cell end faces 231 is 0.8 mm~3 mm, wherein the thickness of the barrier element corresponding to the area of ​​the first cell end face is equal to the thickness of the barrier element corresponding to the second cell end face. An equal thickness serves to facilitate manufacturing.

[0127] In one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, with the barrier element 5 having a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane. The first end face 51, corresponding to the cell end face 231, has a convex structure away from the reference plane, with the maximum outer size of the convex structure being greater than or equal to the cell end face 231. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier element 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and discharging the gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure.At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection. The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0128] In one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, with the barrier element 5 having a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane. The first end face 51, corresponding to the cell end face 231, has a convex structure away from the reference plane, with the maximum outer size of the convex structure being smaller than the cell end face 231. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier element 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and dissipating gas or heat released from the cell under abnormal conditions and preventing safety risks due to excessive pressure.At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection. The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0129] In one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, with the barrier element 5 having a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane. The first end face 51, corresponding to the cell end face 231, has a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier element 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and dissipating gas or heat released from the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection.The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0130] In one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, with the barrier element 5 having a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane. The first end face 51 and the second end face 52, which correspond to the cell end face 231, have a convex structure away from the reference plane. By using a convex structure, the distance between the cell assembly end face and the end face of the barrier element 5 can be increased and the width of the pressure relief space can be increased, thereby more effectively absorbing and dissipating the gas or heat released by the cell under abnormal conditions and preventing safety hazards caused by excessive pressure. At the same time, the convex structure provides a larger surface area, allowing heat to be dissipated more effectively through natural convection.The cell generates heat during charging and discharging. A properly designed heat dissipation structure can keep the cell within a safe operating temperature range and improve thermal management efficiency.

[0131] In one embodiment, the end face of the adjacent cell assembly end face is used as the reference plane, with the barrier element 5 having a first end face 51 close to the reference plane and a second end face 52 remote from the reference plane, with the first end face 51 and the second end face 52 both being planar. In one embodiment, the barrier element 5 is a thermally conductive material with a flash point ≥300°C. A material with a flash point ≥300°C is used to ensure that the barrier element maintains structural integrity in a high-temperature environment or in the event of a thermal runaway of the cell, which is not easily burned or decomposed, and improves the safety of the battery system.By using thermally conductive materials, the barrier element 5 can effectively conduct heat quickly from the battery cell and help to equalize the temperature between the cells, prevent the occurrence of local overheating, and avoid the temperature rise caused by the accumulation of heat inside the battery being too high through good thermal conduction properties, which helps to reduce the risk of thermal runaway.

[0132] In one embodiment, the barrier element 5 is made of a rigid material with a flash point of ≥ 300°C or higher. Using a material with a flash point of ≥ 300°C ensures that the barrier element maintains its structural integrity in a high-temperature environment or in the event of a thermal runaway of the cell, so that it does not easily burn or decompose, and improves the safety of the battery system. Furthermore, the rigid material provides better resistance to thermal conduction, effectively preventing the transmission of flames or high temperatures to the adjacent cell and reducing the risk of a propagating thermal runaway. Under extreme conditions, the material can act as a flame barrier to protect the internal cells from the outside world or other heat sources that may be generated by the cells.

[0133] In one embodiment, the barrier element 5 is a metallic material, and the gap G1 is greater than or equal to 1 mm and less than 10 mm. The metal barrier element forms a non-contact thermal conductivity channel with the cell end face through the gap G1, which can quickly dissipate local high-temperature heat laterally toward the cooling surface of the housing during thermal runaway.

[0134] In one embodiment, the pressure relief airflow from the pressure relief outlet is discharged through the second cooling opening 14. During thermal runaway, the high-temperature and / or high-pressure gas from the pressure relief outlet is directed through the second heat dissipation opening 14 (air outlet), so that the pressure relief airflow and the heat dissipation airflow at the outlet form a superposition effect in the same direction, accelerating the hazardous gas away from the core area of ​​the battery pack and preventing internal gas retention.

[0135] In one embodiment, the pressure relief air flow from the pressure relief outlet flows through the second cooling opening 14, and the material of the second cooling opening is plastic.

[0136] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling hole 14, and the material of the second cooling hole is metal. When the high-temperature gas flows through the metal cooling hole, the heat is quickly transferred through the metal surface to the battery pack casing or the external environment, thereby lowering the temperature of the discharged gas and reducing thermal damage to peripheral components. The metal cooling hole serves as an additional heat dissipation channel and cooperates with the thermal conductivity path of the barrier element to accelerate overall heat dissipation in the battery pack.

[0137] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling port 14. The second cooling port has a pressure relief valve that serves as a conventional cooling channel to help the device maintain normal operating temperature. If the pressure is too high, the pressure relief valve is activated to release the airflow through this port and achieve pressure relief.

[0138] In one embodiment, the barrier element 5 is a metal material containing aluminum. The high thermal conductivity of aluminum enables the barrier element to quickly absorb the local high heat generated during thermal runaway. The heat is transferred to the heat dissipation area of ​​the battery pack casing along the longitudinal direction perpendicular to the cell stacking direction, thereby avoiding horizontal diffusion of heat between the cells. With the same volume, the aluminum-containing material is used as the barrier element, which is lightweight and suitable for scenarios where the battery pack becomes increasingly heavy under the high power demand of the tool, thus achieving breakthroughs in thermal management, lightweight design, and manufacturing costs.

[0139] An example of the tool battery pack

[0140] The housing assembly 1 has a first cooling opening 11, a holder seat (not shown), an opening 13, and a second cooling opening 14. The housing assembly 1 is used to accommodate the cell assembly 2, the pole piece holder 3, and the control device 4; the opening 13 is arranged corresponding to the location of the pole piece holder 3 in the housing assembly 1 so that the tool pole piece penetrates it and connects to the pole piece holder 3.wherein a second cooling opening 14 is arranged on the side of the battery pack with the opening 13, wherein the first cooling opening 11 and the second cooling opening 14 are provided opposite each other on the surface of the housing assembly 1, wherein the first cooling opening 11 is an air outlet, while the second cooling opening 14 is an air outlet, wherein a linear air channel is formed by the arrangement of the first cooling opening 11 and the second cooling opening 14, so that such a direct ventilation path helps the airflow to flow through the battery pack more efficiently, thereby ensuring that the internal temperature of the battery pack is always kept within a safe range, which greatly improves the heat dissipation efficiency of the battery pack and reduces the risk of explosion caused by cell overheating;wherein holder seats (not shown) are provided on at least one side of the housing assembly 1 for securing the cell assembly 2 to prevent movement of the cell holder 22 within the housing assembly 1; wherein the total area of ​​the first cooling opening 11 is larger than the total area of ​​the second cooling opening 14, wherein the air flow enters the housing assembly 1 through the first cooling opening 11 and is then discharged from the second cooling opening 14, wherein the first cooling opening 11 has a larger area which promotes the introduction of more cold air so that the cold air can fully come into contact with the cell assembly 2;

[0141] In one embodiment, the housing assembly 1 also includes a third cooling opening 15, wherein the third cooling opening 15 is arranged on a different side of the housing assembly 1 than the side where the first cooling opening 11 and the second cooling opening 14 are located, so that the air flow can enter the battery pack from that side. The air flow passing through the third cooling opening 15 and the air flow passing through the first cooling opening 11 converge into a single air flow, which is discharged from the second cooling opening 14. With the addition of a third cooling opening 15, the air flow can enter the battery pack in different directions, so that the heat of the cell assembly 2 can be distributed more evenly, thereby avoiding the phenomenon of local overheating.Converging the airflow inside can cover the cell surface more comprehensively and efficiently, maintaining overall heat balance and further enhancing the heat dissipation capacity of the battery pack. This not only increases air circulation and improves the efficiency of internal heat exchange, but also allows the battery pack to fully dissipate heat through other inlet ports even if one cooling port is partially blocked due to external factors, thus ensuring the reliability of the cooling system. This heat dissipation method, with multiple inlet ports and a single outlet port, contributes to a faster reduction of the cell surface temperature.

[0142] In one embodiment, the housing assembly 1 also includes a third cooling opening 15, wherein the third cooling opening 15 is arranged on any one of the two opposite sides of the housing assembly 1 other than the side where the first cooling opening 11 and the second cooling opening 14 are located, so that the airflow can enter the battery pack from this opposite side. The airflow passing through the third cooling opening 15 and the airflow passing through the first cooling opening 11 form a single airflow that is discharged from the second cooling opening 14. With the addition of a third cooling opening 15, the airflow can enter the battery pack in different directions, so that the heat of the cell assembly 2 can be distributed more evenly, thereby avoiding the phenomenon of local overheating.Converging the airflow inside can cover the cell surface more comprehensively and efficiently, maintaining overall heat balance and further enhancing the heat dissipation capacity of the battery pack. This not only increases air circulation and improves the efficiency of internal heat exchange, but also allows the battery pack to fully dissipate heat through other inlet ports even if one cooling port is partially blocked due to external factors, thus ensuring the reliability of the cooling system. This heat dissipation method, with multiple inlet ports and a single outlet port, contributes to a faster reduction of the cell surface temperature.

[0143] In one embodiment, the total area of ​​the third cooling opening 15 is less than or equal to the total area of ​​the second cooling opening 14, thereby solving the problem of localized overheating caused by a single airflow direction. Airflow in the lateral or other directions can flow sufficiently to ensure uniform heat dissipation throughout all parts of the cell, thus avoiding performance losses or risks due to locally high temperatures.The refined arrangement of the cooling holes can better control the temperature gradient in different areas of the device, and the arrangement with multiple inlet holes and one outlet hole makes it possible to ensure sufficient airflow and heat dissipation in the remaining cooling holes when one of the cooling holes fails due to external blockage or other problems, thus ensuring the continuity and reliability of the system.

[0144] In one embodiment, the total area of ​​the third cooling opening 15 is larger than the total area of ​​the second cooling opening 14, thereby solving the problem of localized overheating caused by a single airflow direction. Airflow in the lateral or other directions can flow sufficiently to ensure uniform heat dissipation in all parts of the cell, thus avoiding performance losses or risks due to locally confined high temperatures.The refined arrangement of the cooling holes can better control the temperature gradient in different areas of the device, and the arrangement with multiple inlet holes and one outlet hole makes it possible to ensure sufficient airflow and heat dissipation in the remaining cooling holes when one of the cooling holes fails due to external blockage or other problems, thus ensuring the continuity and reliability of the system.

[0145] In one embodiment, the second cooling opening 14 is provided in a central area on one side of the housing assembly 1 with an opening 13, this side facing the first cooling opening 11, so that the airflow can cover the surface of the cell assembly 2 more evenly. Distributing the airflow from the center to the periphery reduces the problem of local heat concentration and contributes to maintaining a uniform temperature distribution inside the battery pack.

[0146] In one embodiment, the second cooling opening 14 is provided near the opening 13 in a central area on one side of the housing assembly 1 with an opening 13, which side faces the first cooling opening 11, so that the airflow can cover the surface of the cell assembly 2 more evenly. Distributing the airflow from the center to the periphery reduces the problem of local heat concentration and contributes to maintaining a uniform temperature distribution inside the battery pack.

[0147] In one embodiment, the housing assembly 1 has a locking position 16. The housing assembly 1 is used to lock the battery pack to prevent movement of the battery pack. The second cooling opening 14 is provided in a central region on one side of the housing assembly 1 with an opening 13 between the second cooling opening 14 and the locking position 16, this side facing the first cooling opening 11, so that the airflow can cover the surface of the cell assembly 2 more evenly. The distribution of the airflow, which spreads from the center to the periphery, reduces the problem of local heat concentration and contributes to maintaining a uniform temperature distribution inside the battery pack.

[0148] In one embodiment, the housing assembly 1 is a 2-split mold combination, wherein the housing assembly 1 is constructed as a concave housing with openings on the top or on both sides, wherein the end caps are connected to the housing from the opening side; wherein the housing assembly 1 is a 3-split mold combination, wherein the housing assembly 1 is constructed as a one-piece, continuously split housing with openings on opposite sides, wherein the end caps are connected to the housing from the openings; wherein the housing assembly 1 is a 4-split mold combination, wherein the housing assembly 1 is constructed as a continuously split housing with openings on opposite sides, wherein the housing is attachable at the top and bottom, wherein the end caps are connected to the housing from the openings; wherein the housing assembly 1 is assembled without particular restriction.

[0149] In one embodiment, the housing assembly 1 further comprises a water outlet opening 113, wherein the water outlet opening 113 is provided on at least one side other than the surface of the battery pack on which the opening 13 is located, in order to drain water entering the housing assembly 1.

[0150] The cell assembly 2 comprises a unit cell 23, a cell holder 24, a waterproofing layer 25 and a waterproofing member 26;

[0151] The unit cell 23 is a cylindrical cell with a first cell end face 2311 and a second cell end face 2312.

[0152] With reference to Fig. 5, in one embodiment, the first cell end face 2311 has a positive pole end face 23111 and the positive pole end face 23111 is a flat end face.

[0153] In one embodiment, the first cell end face 2311 has a positive pole end face 23111 and the positive pole end face 23111 has a cap end face 231111, wherein the cap end face 231111 protrudes outwardly from the positive pole end face 23111.

[0154] With reference to the Fig. 5 and Fig. 9, in one embodiment, includes the first cell end face 2311, a positive terminal end face 23111, and also a negative terminal end face 2312. A separator 2313 is provided between the negative terminal end face 2312 and the positive terminal end face 23111 to isolate the positive electrode from the negative electrode to prevent short circuiting. At the first cell end face 2311, the exposed hole 242 exposes the first edge, with the edge of the negative terminal end face 2312 near the central axis of the unit cell 23 being the first edge, and the projection distance c between the first edge and the edge within the exposed hole 242 being greater than or equal to 0.1 mm. With a distance between the exposed hole 242 and the first edge, not only is the technical insulation structurally improved, but also the water sealing layer 25 is allowed to cover the negative terminal end face 2312 and the separator 2313.Once the separator 2313 breaks or fails due to aging, the waterproofing layer 25 becomes an additional barrier layer that prevents water vapor from penetrating the cell. At the same time, the waterproofing layer 25 covers the negative terminal end face 2312 and the exposed hole 242, preventing water vapor from penetrating the cell end face along its length from the mounting gaps of the receiving slot 241 and further from coming into contact with the positive terminal end face and negative terminal end face 2312, thus preventing a potential short circuit.

[0155] With reference to Fig. 4, the cell holder 24 has a receiving slot 241, an exposed hole 242, a first end 243, a second end 244, wherein the first end 243 of the cell holder 24 has a receiving slot 241 that receives the unit cell 23, wherein one end of the receiving slot 241 has a groove into which the unit cell 23 projects, wherein the other end of the receiving slot 241 has an exposed hole 242 that extends through the cell holder 24, wherein the area within the exposed hole 242 is smaller than the cross-sectional area of ​​the receiving slot 241 that is parallel to the exposed hole 242, wherein the area of ​​the exposed hole 242 is smaller than the maximum area of ​​the first cell end surface 2311 that extends into the receiving slot 241, wherein the shape of the exposed hole 242 has a rounded shape, a includes, but is not limited to, oval shape, square shape and other shapes;wherein the cell holder 24 is securely attached to the holder seat 12 within the housing assembly 1 by means of, but not limited to, a welded or screwed connection to provide additional structural support and protection against vibrations;

[0156] As in Fig. 17, in one embodiment, the cell holder 24 includes a limiting portion 245 that cooperates with the holder seat 12, the limiting portion 245 including a locking element 2451, the locking element 2451 being in a form that includes, but is not limited to, a structural locking shape, the locking element 2451 being a screw hole, or being screwed into place by a screw, or the locking element 2451 being a first slot and tenon structure and being attached to the housing assembly 1 by a second slot and tenon structure by snapping it in, or by welding the limiting portion 245 to the housing assembly 1, or by locking it by gluing or other methods to ensure that the cell holder 24 does not move within the housing assembly 1.

[0157] In one embodiment, the hole height d of the exposed hole 242 is greater than or equal to 0.5 mm and less than or equal to 2.5 mm. By setting the hole height d of the exposed hole 242 to greater than or equal to 0.5 mm, an effective support strength for the unit cell 23 can be achieved, preventing the position of the unit cell 23 from shifting due to vibration or other external forces during normal use, thus improving the overall mechanical stability and safety of the battery pack. Since it is less than or equal to 2.5 mm, the use of unnecessary materials can be avoided while strengthening the support force, thereby optimizing the weight of the battery pack and further improving energy efficiency and endurance performance. When designing the height range, the utilization rate of the cell's internal space is also taken into account.Based on safe mechanical support, the appropriate setting of the height inside the hole avoids unnecessary occupancy of the effective space of the battery pack, so that the battery pack can maximize the capacity and energy density within the limited space.

[0158] The waterproofing layer 25 is provided at the second end 244 of the cell holder 24 by any glue filling or vacuum deposition process. The waterproofing layer 25 covers the first cell end face 2311 and the second cell end face 2312 of the unit cell 23 to prevent a short circuit caused by contact between the first cell end face 2311, the second cell end face 2312, and the outside water vapor.

[0159] With reference to the Fig. 17-24, the waterproofing member 26 is provided at a second end 246 of the cell holder 24, the waterproofing member 26 having a first end surface 261 remote from the cell holder 24 and a second end surface 262 proximate the cell holder 24, and at least a portion of the waterproofing layer between the second end surface 262 and the cell holder 24. The addition of the waterproofing member 26 eliminates the need to wait for the waterproofing layer to dry for subsequent assembly work after covering the waterproofing layer 23 on the cell holder 24, which greatly improves the efficiency of the production line, reduces waiting time, and improves the flexibility and responsiveness of production.

[0160] With reference to Fig. 17 and Fig. 19, in one embodiment, the first end face 261 has a first convex surface 2611 at the exposed hole 242, which protrudes toward the end face of the unit cell 23, and the second end face 262 is a flat surface. The water sealing member 26 has a first convex surface 2611 at the position of the exposed hole 242, and the water sealing member 26 is formed in the weak region of the exposed hole 242. When the cell has an abnormal overtemperature, it usually has a high-voltage and high-temperature fire in the region of the first cell end face 2311. At this time, the abnormal unit cell 23 can quickly break through the water sealing plate in the weak region, thereby providing a safe pressure relief mechanism to prevent the adjacent unit cell 23 or the adjacent cell assembly 2 from being affected, so that continuous deflagration occurs.

[0161] With reference to Fig. 17 and Fig. 19, in one embodiment, the first end surface 261 has a first convex surface 2611 at the exposed hole 242, which protrudes toward the end surface of the unit cell 23, and the second end surface 262 is a flat surface, wherein the distance b between the first convex surface 2611 and the second end surface 262 is greater than 0.3 mm and less than or equal to 3 mm. By setting the range of the distance b between the first convex surface 2611 and the second end surface 262, the thickness of the weak area can be controlled as much as possible to be easily broken. At the same time, it effectively prevents the problem of the waterproofing layer being broken due to improper operation during the pressing process, and ensures that it simultaneously provides waterproof protection and a clear and controlled safe pressure relief channel for abnormal conditions such as high pressure and high temperature.In addition, by clarifying the range of b, the thickness of the weak point area can be maintained in the manufacturing process, which not only ensures quality control in mass production, but also can improve the stability of the production process.

[0162] In one embodiment, the second end surface 262 is as shown in Fig. 20 is not planar, wherein the second end surface 262 has a second convex surface 2621 at the exposed opening 242 protruding toward the end surface of the unit cell 23, wherein the distance a-2 between the second convex surface 2621 and the positive terminal end surface 23111 is greater than or equal to 0.1 mm, or the distance a-1 between the second convex surface 2621 and the cap end surface 231111 is greater than or equal to 0.1 mm. By setting the range of a-1 and a-2, the thickness of the waterproofing layer in the weak area can be controlled as much as possible under the effective waterproofing protection, thereby providing a clear and controlled safe pressure relief channel for high pressure, high temperature, and other abnormal situations.In addition, by clarifying the range of a-1 and a-2, the thickness of the weak point area can be maintained in the manufacturing process, which not only ensures quality control in mass production, but also can improve the stability of the production process.

[0163] In one embodiment, the second end surface 262 is as shown in Fig. 20 is not planar, wherein the second end surface 262 has a second convex surface 2621 at the exposed opening 242 protruding toward the end surface of the unit cell 11, wherein the distance a-2 between the second convex surface 2621 and the positive terminal end surface 23111 is greater than or equal to 0.1 mm and less than 2 mm, or the distance a-1 between the second convex surface 2621 and the cap end surface 231111 is greater than or equal to 0.1 mm and less than 2 mm. By setting the range of a-1 and a-2, the thickness of the waterproofing layer in the weak area can be controlled as much as possible under the effective waterproofing protection, thereby providing a clear and controlled safe pressure relief channel for high pressure, high temperature, and other abnormal situations.In addition, by clarifying the range of a-1 and a-2, the thickness of the weak point area can be maintained in the manufacturing process, which not only ensures quality control in mass production, but also can improve the stability of the production process.

[0164] In one embodiment, the second end surface 262 has as in Fig. 17-20, a second convex surface 2621 on the exposed opening 242 protruding toward the end face of the unit cell 23, wherein the distance between the second convex surface 2621 and the positive terminal end face 23111 is greater than or equal to 0.5 mm and less than 1 mm, or the distance a-1 between the second convex surface 2621 and the cap end face 231111 is greater than or equal to 0.5 mm and less than 1.5 mm. By setting the range of a-1 and a-2, the thickness of the waterproofing layer in the weak area can be controlled as much as possible under the effective waterproofing protection, thereby providing a clear and controlled safe pressure relief channel for high pressure, high temperature, and other abnormal situations.In addition, by clarifying the range of a-1 and a-2, the thickness of the weak point area can be maintained in the manufacturing process, which not only ensures quality control in mass production, but also can improve the stability of the production process.

[0165] In one embodiment, the second end surface 262 has a second convex surface 2621 at the exposed opening 242, which protrudes toward the end surface of the unit cell 11, wherein the distance a-2 between the second convex surface 2621 and the positive terminal end surface 23111 is greater than or equal to 0.3 mm and less than or equal to 0.8 mm, or the distance a-1 between the second convex surface 2621 and the cap end surface 231111 is greater than or equal to 0.3 mm and less than or equal to 1.2 mm. By setting the range of a-1 and a-2, the thickness of the waterproofing layer in the weak area can be controlled as much as possible under the effective waterproofing protection, thereby providing a clear and controlled safe pressure relief channel for high pressure, high temperature, and other abnormal situations.In addition, by clarifying the range of a-1 and a-2, the controllability and consistency of the thickness of the weak point area can be maintained in the manufacturing process, which not only ensures quality control in mass production but also can improve the stability of the production process.

[0166] In one embodiment, the water sealing element 26 is as shown in Fig. 12-13 a non-metallic material having a heat softening temperature greater than or equal to 90°. As in Fig. As shown in Figure 17, the temperature rise of the cell end face of the 60V unit cell 23 during the 30A discharge process is approximately 60°C. As the current increases, the temperature rise of the cell end face also increases. If the temperature of the cell exceeds abnormal values ​​during the charge and discharge process, it will typically experience a high-voltage and high-temperature fire in the region of the first cell end face 2311. At this time, the temperature of the cell end face is usually above 100°C. Since the water seal member 26 is a non-metallic material with a thermal softening temperature greater than or equal to 90°C, the water seal member 26 may soften spontaneously during the heating process of the abnormal unit cell 23.At this time, the abnormal unit cell 23 can break through the water sealing element in the weak area more quickly, thereby providing a safe pressure relief mechanism to avoid continuous deflagration affecting the adjacent unit cell 23 or the adjacent cell assembly 2. At the same time, in order to achieve a stable and effective waterproof effect, it cannot be affected by temperature during the heating process of the normal unit cell 23.

[0167] In one embodiment, the waterproofing member 26 is ABS\PC\PP\PE\Nylon\PA\GF. By setting the waterproofing member 26 to ABS\PC\PP\PE\Nylon\PA\GF, the waterproofing member 26 can soften itself during the heating process of the abnormal unit cell 23. At this time, the abnormal unit cell 23 can break through the waterproofing member in the weak area more quickly, thereby providing a safe pressure relief mechanism to prevent continuous deflagration from affecting the adjacent unit cell 23 or the adjacent cell assembly 2. At the same time, to achieve a stable and effective waterproofing effect, it cannot be affected by temperature during the heating process of the normal unit cell 23.

[0168] In one embodiment, the water sealing member 26 is a uniform-thickness water sealing plate having a thickness greater than or equal to 0.3 mm and less than or equal to 3 mm. The water sealing member 26 has a first convex surface 2611 and a second convex surface 2621 at the exposed hole 242, which protrude toward the end face of the unit cell 23. The convex surface 2611 and the second convex surface are formed in the weak region of the exposed hole 242. When the cell has an abnormal overtemperature, it usually has a high-voltage, high-temperature fire in the region of the first cell end face 2311.At this time, the abnormal unit cell 23 can quickly break through the water seal plate in the weak area, thereby providing a safe pressure relief mechanism to avoid affecting the adjacent unit cell 23 or the adjacent cell assembly 2, so that continuous deflagration occurs.

[0169] In one embodiment, the water sealing member 26 is a water sealing plate with uneven thickness, wherein the thickness of the water sealing member 26 at the exposed hole 242 is less than the thickness of the water sealing member 26 outside the exposed hole 242, and the water sealing member 26 is formed in the weak region of the exposed hole 242. When the cell has an abnormal overtemperature, it usually has a high-voltage, high-temperature fire in the region of the first cell end face 2311. At this time, the abnormal unit cell 23 can quickly break through the water sealing plate in the weak region, thereby providing a safe pressure relief mechanism to prevent the adjacent unit cell 23 or the adjacent cell assembly 2 from being affected, so that continuous deflagration occurs.

[0170] In one embodiment, the water seal member 26 has a positioning member 266, wherein the positioning member 266 is a positioning hole, wherein the positioning post is provided in the cell holder 24, wherein the positioning post has a size of 1 mm-10 mm, which enables effective positioning.

[0171] In one embodiment, the water seal member 26 has a positioning member 266, wherein the positioning member 266 is a positioning post, wherein the positioning post has a size of 0.5 mm-2 mm, wherein the positioning hole is provided in the cell holder 24, wherein the positioning hole can accommodate some or all of the positioning;

[0172] In one embodiment, the water seal member 26 forms a limited fit on the cell holder 24. Embodiments include, but are not limited to, snap-fit ​​structural connections, welding, adhesive bonding, and other forms of process connection that are not limited to a mortise and tenon structure.

[0173] With reference to Fig. 25 - Fig. 26, the pole piece holder 3 has a terminal assembly 32, a terminal mounting seat 33, the terminal mounting seat 33 having a guide slot 331, a mounting end 332, and a water sealing space 333, the guide slot 331 being used to guide the tool pole piece in the correct insertion direction to avoid a short circuit caused by the installation error, and at the same time still being used to stabilize the tool pole piece to ensure that it is effectively connected to the control device 4; the mounting end 332 being used for firmly connecting to the control device 4.The water sealing space 333 includes a first water sealing space 3331, a second water sealing space 3332, wherein the first water sealing space 3331 is a mounting gap between the terminal mounting seat 33 and the terminal assembly 32 when the terminal mounting seat 33 is limited to the terminal assembly 32, wherein the second water sealing space 3332 is a mounting gap between the terminal mounting seat 33 and the control device 4, wherein the second water sealing space 3332 has at least one inlet opening 33321, wherein the inlet opening 33321 is arranged between the terminal mounting seat 33 in the control device 4.The position of the inlet opening 33321 is designed to facilitate the waterproofing material's rapid and even penetration into and filling the second waterproofing chamber 3332 during operation, achieving efficient waterproofing during assembly and maintenance and maintaining the safe operation of the control device for a long time. Completely filling the second waterproofing chamber 3332 provides a basic waterproofing barrier for the terminal assembly 32, protecting the internal structure from moisture and contaminants that could cause the control board to malfunction.

[0174] In one embodiment, the fixing end 332 has a height of greater than or equal to 0.5 mm and less than or equal to 3 mm in a columnar shape, the first end of the fixing end 332 being connected to the terminal fixing seat 33, the second end being connected to the control device 4, the fixing end 332 supporting the terminal fixing seat 33 so that the terminal fixing seat 33 is not in contact with the control device 4, the second waterproof space 3332 being the projection area from the terminal fixing seat 33 in the control device 4, the terminal fixing seat 33 being located in the non-contact space between control devices 4.

[0175] In one embodiment, the terminal fixing seat 33 has a fixing end 332 in a projecting shape on the side near the control device 4, the fixing end 332 being connected to the control device 4, the fixing end 332 supporting the terminal fixing seat 33 so that the terminal fixing seat 33 is not in contact with the control device 4, the second waterproof space 3332 forming the projection area of ​​the terminal fixing seat 33 in the control device 4, the terminal fixing seat 33 being located in a non-contact space between control devices 4.

[0176] In one embodiment, the waterproofing material of the first waterproofing space 3331 and the second waterproofing space 3332 is encapsulated in a single molded part by vacuum deposition, wherein the height distance of the inlet opening 33321 is greater than or equal to 0.5 mm and / or the lowest height distance of the second waterproofing space 3332 is greater than or equal to 0.5 mm. A distance greater than or equal to 0.5 mm allows the waterproofing material to be better filled into the second waterproofing space 3332 under the compression of the overall size of the battery pack by vacuum deposition, while preventing the central region of the second waterproofing space 3332 from being filled in place and the waterproofing material from being unevenly distributed in the second waterproofing space 3332.

[0177] In one embodiment, the waterproofing material of the first waterproofing space 3331 and the second waterproofing space 3332 is encapsulated in a single molded part by low-pressure injection molding, wherein the height distance of the inlet opening 33321 is greater than or equal to 0.8 mm and / or the lowest height distance of the second waterproofing space 3332 is greater than or equal to 0.8 mm. A distance greater than or equal to 0.8 mm allows the waterproofing material to be better filled into the second waterproofing space 3332 by low-pressure injection molding under the compression of the overall size of the battery pack, preventing the central region of the second waterproofing space 3332 from being filled in place and the waterproofing material from being unevenly distributed in the second waterproofing space 3332.

[0178] In one embodiment, the waterproofing material of the first waterproofing space 3331 and the second waterproofing space 3332 is encapsulated in a single molded part by the glue filling, wherein the height distance of the inlet opening 33321 is greater than or equal to 0.5 mm and / or the lowest height distance of the second waterproofing space 3332 is greater than or equal to 0.5 mm. By setting a distance greater than or equal to 0.5 mm, the waterproofing material can be better filled into the second waterproofing space 3332 under the compression of the overall size of the battery pack by glue filling, while preventing the central region of the second waterproofing space 3332 from being filled in place and the waterproofing material from being unevenly distributed in the second waterproofing space 3332.

[0179] The control device 4 is provided on the cell holder 22, the control device 4 comprising a control board 41 and a connector 42, the control board 41 comprising at least a control module and a communication module, the control board 41 connecting the unit cell 23 from the exposed hole 242 through the connector 42 to achieve at least the communication and control functions, the control module serving to regulate parameters such as the voltage, the current and the temperature in the battery pack to ensure the safe and efficient operation of the entire system, the communication module serving to exchange data with an external device to realize the monitoring of the operating state of the battery pack.

[0180] With reference to Fig. 27 - Fig. 30, the connecting member 42 includes unit cell detection elements 421 and connecting pole pieces 422, the unit cell detection element 421 having a first connection end 4211 and a second connection end 4212, the connecting pole piece 422 being connected to the first connection end 4211, the connecting pole piece 422 being connected to the unit cell 21 through the exposed hole 242, and the second connection end 4212 being connected to the control board 41 by welding to avoid problems that the terminals have poor waterproof performance due to messy wiring through the terminal connection and control board and are inconvenient to maintain inside the battery pack.

[0181] In one embodiment, the second connection end 4212 has at least one first weld plate 42121 corresponding to the number of unit cells 21, wherein the control board 41 has at least one second weld plate 411 corresponding to at least the number of first weld plates 42121 at the second connection end 4212, wherein the area of ​​the first weld plate 42121 is less than or equal to the area of ​​the second weld plate 411. With the construction that the area of ​​the first weld plate 42121 is less than or equal to the area of ​​the second weld plate 411, a smaller area of ​​the first weld plate 42121 allows it to fully adhere to the larger second weld plate 411, reducing the risk of possible short circuits between adjacent weld plates, thereby improving the safety and reliability of the circuit and ensuring good thermal conduction and electrical connection.At the same time, the smaller weld plate acts on the larger weld plate during thermal expansion, reducing the mechanical stress caused by thermal expansion and contraction, thus reducing fatigue and potential cracking at the brazing joints. This configuration increases the mechanical strength of the weld and improves the stability and durability of the joint.

[0182] In one embodiment, the second connection end 4212 has at least one first welding plate 42121 corresponding to the number of unit cells 21, wherein the control board 41 has at least one second welding plate 411 corresponding at least to the number of first welding plates 42121 at the second connection end 4212, wherein the first welding plate 42121 has at least one through hole 42122 passing through the first welding plate 42121, wherein the ratio between the opening of the through hole 42122 and the width of the welding plate of the first welding plate 42121 in which the opening is located is less than or equal to 1:2.By setting a ratio of less than or equal to 1:2 between the opening of the through-hole 42122 and the width of the weld plate of the first weld plate 42121, in which the opening is located, the solder penetration ability through the through-hole during the soldering process is increased, improving the mechanical strength and the strength of the conductive connection. The through-hole allows for better solder filling to form a more robust and better conductive connection.

[0183] In one embodiment, the second connection end 4212 has at least one first welding plate 42121 corresponding to the number of unit cells 21, wherein the control board 41 has at least one second welding plate 411 corresponding to at least the number of first welding plates 42121 at the second connection end 4212. In the first welding plate 42121 and / or the second welding plate 411, the minimum distance e between adjacent welding plates is greater than or equal to 0.2 mm and less than or equal to 2 mm. By setting the minimum distance e between adjacent welding plates to be greater than or equal to 0.2 mm and less than or equal to 2 mm, the risk of a short circuit due to solder bridges or contamination by conductive particles is effectively reduced, and welding defects triggered by prestress in the manufacturing process can also be reduced.During manufacturing and operation, increased spacing provides greater tolerance for errors in soldering and subsequent operations, increases overall circuit safety and reliability, prevents signal crosstalk, improves signal integrity and transmission efficiency, and allows each area of ​​the weld plate to effectively dissipate heat, avoiding excessive concentration of local overheating problems caused by increased weld plate spacing, allowing better heat diffusion and control.

[0184] In one embodiment, the second connection end 4212 has at least one first welding plate 42121 corresponding to the number of unit cells 21, and the control board 41 has at least one second welding plate 411 corresponding to at least the number of first welding plates 42121 at the second connection end 4212. The distance f between the peripheral component and the adjacent welding area of ​​the first welding plate 42121 and / or the second welding plate 411 is greater than or equal to 1 mm and less than or equal to 25 mm. By setting f to be greater than or equal to 1 mm and less than or equal to 25 mm, the distance between the welding plate and the peripheral components can be increased, which contributes to reducing mutual interference due to electromagnetic interference.This physical isolation can reduce signal coupling on the circuit board, improve signal integrity, and ensure more stable electrical performance. At the same time, the increased distance between the components and the weld plate reduces the risk of short circuits due to accidental contact or material bridging (e.g., solder overflow), and the danger of a short circuit, which can lead to a larger safety margin for production and subsequent operation of the device. The increased distance also improves the thermal diffusion capabilities of the circuit board, allowing heat to be more effectively dissipated from the high-temperature zone, preventing local overheating and heat buildup problems.

[0185] In one embodiment, the tinning thickness of the first welding plate 42121 and / or the second welding plate 411 is 0.05-0.15 mm. By controlling the tinning thickness to 0.05-0.15 mm, excessive solder flow during the welding process can be reduced and the risk of welding bridges and short circuits can be reduced, thereby improving the electrical insulation effect of the welding area, as shown in Figures 15 and 17.In one embodiment, the barrier element 5 is arranged between the third cell assembly end surface 221 and the second cell assembly end surface 212, wherein the third cell assembly end surface 221 serves as a reference plane, wherein the barrier element 5 has a first end surface 51 close to the reference plane and a second end surface 52 remote from the reference plane, wherein a first pressure relief space 55A is formed between the first end surface 51 and the third cell assembly end surface 221, wherein a distance G1 exists between the first end surface 51 and the third cell assembly end surface 221, wherein a second pressure relief space 55B is formed between the second end surface 52 and the second cell assembly end surface 212, wherein a distance G2 exists between the second end surface 52 and the second cell assembly end surface 212, wherein the first pressure relief space 55A and the second pressure relief space 55B have at least one pressure relief outlet 55.Compared to existing tool battery packs that are not configured with a barrier element, when the unit cell is in thermal runaway, it is not possible to achieve thermal diffusion of high-temperature gases and flames escaping from the cell end face toward the housing assembly 1 and / or the cell assembly 2, causing it to rupture and destroy. In this application, the barrier element is disposed between the third cell assembly end face 221 and the second cell assembly end face 212, thus introducing a relatively self-contained pressure relief space between adjacent cell assemblies to form a physical barrier. Through the mating structure of the receiving slot 241 and the exposed hole 242, each unit cell 23 forms a separate air chamber.With the compartmental isolation effect of the barrier element 5, the impact area of ​​thermal runaway of the unit cell can be limited within the two adjacent unit cells. The pressure relief space formed between the barrier element 5 and the cell assembly end face, together with the design of the pressure relief outlets, establishes a directional pressure relief mechanism and can directly direct high-temperature gases and flames generated by thermal runaway to a predetermined safe area, effectively reducing the risk of internal pressure buildup. This significantly reduces the likelihood of fires, explosions, and other accidents affecting the entire battery pack in the event of a unit cell thermal runaway, and improves the overall reliability and safety of the battery.

[0186] As in Fig. 14, in one embodiment, the third cell assembly end face 221 has a first cell end face 2311. When the cell end face of the second cell end face 212 that is opposite the first cell end face 2311 of the third cell assembly end face 221 is the first cell end face 2311 (it is understood that for two cell assemblies, one of the two adjacent sets of cell assembly end faces is the positive terminal and the opposite cell end face is also a positive terminal.), the distance between the second end surface 52 and the positive pole end surface 23111 or the cap end surface 231111 or the negative pole end surface 23112 of the third cell assembly end surface 221 is the distance G1, wherein the distance G1 is greater than or equal to 1 mm and less than 10 mm; wherein the distance between the first end surface 51 and the positive pole end surface 23111 or the cap end surface 231111 or the negative pole end surface 23112 of the second cell assembly end surface 212 is the distance G2, wherein the distance G2 is greater than or equal to 1 mm and less than 10 mm. By establishing a pressure relief space at a distance between G1 and G2, a buffer zone can be effectively established in the assembly opposite to the cell assembly end face. Limiting the heat dissipation capacity of the cell from thermal runaway in the entire tool battery pack is an important factor to ensure the safety of the tool battery pack.By precisely controlling the gap (distance G1, distance G2), the initial heat wave can be blocked according to this program and the heat wave is directed toward a specific space for pressure relief, effectively limiting the heat wave in the thermally burned unit cell and the thermal propagation in all four directions of the adjacent unit cell. This effectively delays or prevents thermal runaway from being transmitted from one cell to the entire tool battery pack. It also ensures that the overall size of the tool battery pack does not become too large, so that the tool battery pack design can still be applied to existing tools and equipment while maintaining safety and performance. A standardized gap size makes the system simpler and more efficient in terms of operation during production and assembly.

[0187] In one embodiment, the distance G1 and the distance G2 are equal. Because the distance G1 and the distance G2 are equal, the compensation interval is in the early stage of thermal runaway. The symmetrical distance G1 / G2 causes the high-temperature gas to be discharged from the first space and the second pressure relief space in parallel at the same flow rate, avoiding local air turbulence caused by uneven pressure relief and reducing the risk of heat wave superposition. The equidistant design of the double pressure relief space forms a pressure relief compensation mechanism in both directions.If abnormal gas production occurs on one side of the cell assembly, the symmetrical channel can automatically equalize the pressure difference on both sides, preventing structural deformation caused by overstress on one side and simultaneously suppressing a chain reaction of thermal runaway. The balanced pressure relief channel allows heat to be evenly distributed along the axial direction of the battery pack. Combined with the high-temperature resistance properties of the barrier element, the problem of thermal stress concentration between cells is significantly reduced.

[0188] In one embodiment, the difference between the distance G1 and the distance G2 is less than or equal to 3 mm, and the ΔG difference constructs an asymmetric heat conduction path, which enables differentiated management of heat propagation in the space, increasing the gap in high-risk areas such as the positive terminal cell end face and narrowing the gap in the negative terminal cell end face in low-risk areas, thereby making heat management more flexible and efficient. Through detailed space management, the safety performance of the tool battery pack during thermal runaway is optimized while ensuring its compactness and applicability. This design enhances the practical application effect of the tool battery pack.

[0189] In one embodiment, the cell end face 231 comprises a first cell end face 2311 and a second cell end face 2312, wherein the cell assembly end face comprises at least two cell end faces 231, wherein the thickness J of the barrier element 5, corresponding to the area of ​​the cell end faces 231, is 0.8 mm~3 mm. It can provide sufficient space for pressure relief while maintaining structural strength if the thickness J of the barrier element is in the range between 0.8 mm~3 mm. This thickness contributes to effectively conducting and releasing pressure under extreme conditions (e.g., thermal runaway).The thickness range is also sufficient to provide effective thermal insulation and slow heat conduction from one cell to neighboring cells, increasing the safety of the battery system and ensuring that the barrier element does not add excessive weight or take up too much space while providing support and insulation, ensuring overall low weight and compactness of the tool battery pack.

[0190] In one embodiment, the barrier element 5 is a metallic material, and the gap G1 is greater than or equal to 1 mm and less than 10 mm. The metal barrier element forms a non-contact thermal conductivity channel with the cell end face through the gap G1, which can quickly dissipate local high-temperature heat laterally toward the cooling surface of the housing during thermal runaway.

[0191] In one embodiment, the pressure relief airflow from the pressure relief outlet is discharged through the second cooling opening 14. During thermal runaway, the high-temperature and / or high-pressure gas from the pressure relief outlet is directed through the second heat dissipation opening 14 (air outlet), so that the pressure relief airflow and the heat dissipation airflow at the outlet form a superposition effect in the same direction, accelerating the hazardous gas away from the core area of ​​the battery pack and preventing internal gas retention.

[0192] In one embodiment, the pressure relief air flow from the pressure relief outlet flows through the second cooling opening 14, and the material of the second cooling opening is plastic.

[0193] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling hole 14, and the material of the second cooling hole is metal. When the high-temperature gas flows through the metal cooling hole, the heat is quickly transferred through the metal surface to the battery pack casing or the external environment, thereby lowering the temperature of the discharged gas and reducing thermal damage to peripheral components. The metal cooling hole serves as an additional heat dissipation channel and cooperates with the thermal conductivity path of the barrier element to accelerate overall heat dissipation in the battery pack.

[0194] In one embodiment, the pressure relief airflow from the pressure relief outlet flows through the second cooling port 14. The second cooling port has a pressure relief valve that serves as a conventional cooling channel to help the device maintain normal operating temperature. If the pressure is too high, the pressure relief valve is activated to release the airflow through this port and achieve pressure relief.

[0195] In one embodiment, the barrier element 5 is a metal material containing aluminum. The high thermal conductivity of aluminum enables the barrier element to quickly absorb the local high heat generated during thermal runaway. The heat is transferred to the heat dissipation area of ​​the battery pack casing along the longitudinal direction perpendicular to the cell stacking direction, thereby avoiding horizontal diffusion of heat between the cells. With the same volume, the aluminum-containing material is used as the barrier element, which is lightweight and suitable for scenarios where the battery pack becomes increasingly heavy under the high power demand of the tool, thus achieving breakthroughs in thermal management, lightweight design, and manufacturing costs.

[0196] In one embodiment, a tool battery pack further comprises a barrier element 5 with a thermally conductive effect, wherein the barrier element is arranged on a cell assembly end face by means of a positioning connector, wherein the cell assembly end face serves as a reference plane, wherein the thermal conduction effect system refers to the thermal conductivity of a material under steady-state heat transfer conditions. Its technical properties are that the thermal conductivity value is ≥5 W / (m K), wherein the barrier element 5 is arranged on a cell assembly end face by means of a positioning connector 57, wherein the cell assembly end face is as in Fig. 4 serves as a reference plane, wherein the barrier element 5 has a first end surface 51 close to the reference plane and a second end surface 52 remote from the reference plane, wherein a distance G1 exists between the first end surface 51 and the cell assembly end surface, wherein a pressure relief space 53 is formed between the first end surface 51 and the cell assembly end surface, wherein the pressure relief space has at least one pressure relief outlet 55. Due to the mating structure of the receiving slot 241 and the exposed hole 242, each unit cell 23 forms a separate air chamber. With the compartmentalization effect of the barrier element 5, the range of influence of the thermal runaway of the unit cell can be limited within the two adjacent unit cells.The pressure relief space formed between the barrier element 5 and the cell assembly end face, together with the design of the pressure relief outlets, establishes a directional pressure relief mechanism and can direct high-temperature gases and flames generated by thermal runaway to a predetermined safe area, effectively reducing the risk of internal pressure buildup. At the same time, it plays a dual role of barrier and protection, and the barrier element 5 with thermal conductivity can be used as a physical barrier to prevent the flame from directly impacting the housing and / or adjacent cells.The local high temperature can also be quickly distributed to the entire heat dissipation system of the battery pack through the thermal conductivity characteristics, so that the gaseous flame is extinguished due to the cooling effect of the metal surface in the gap, and the solid melt is blocked in the pressure relief space to avoid splashing to adjacent cells, so that the probability of fire, explosion and other accidents of the entire battery pack in the event of thermal runaway of the unit cell can be greatly reduced, and the overall reliability and safety of the battery can be improved.

[0197] In one embodiment, the barrier element 5 is made of a rigid material with a flash point of ≥ 300°C or higher. Using a material with a flash point of ≥ 300°C ensures that the barrier element maintains its structural integrity in a high-temperature environment or in the event of a thermal runaway of the cell, so that it does not easily burn or decompose, and improves the safety of the battery system. Furthermore, the rigid material provides better resistance to thermal conduction, effectively preventing the transmission of flames or high temperatures to the adjacent cell and reducing the risk of a propagating thermal runaway. Under extreme conditions, the material can act as a flame barrier to protect the internal cells from the outside world or other heat sources that may be generated by the cells.

[0198] As in Fig.As shown in Figure 4, in one embodiment, the distance between the first end surface 51 and the positive terminal end surface 23111 or the cap end surface 231111 or the negative terminal end surface 23112 of the cell assembly end surface is the distance G1. The distance G1 is greater than or equal to 1 mm and less than 10 mm. By establishing a pressure relief space at a distance of G1, a buffer zone can be effectively established in the assembly opposite the cell assembly end surface. Limiting the heat dissipation capacity of the cell from thermal runaway in the entire tool battery pack is an important factor in ensuring the safety of the tool battery pack.By precisely controlling the gap distance G1 according to this program, the initial heat wave can be blocked and directed toward a specific pressure relief space, effectively limiting the heat wave in the thermally burned unit cell and thermal propagation in all four directions to the adjacent unit cell 23 and / or the housing assembly 1. This effectively delays or prevents thermal runaway from being transmitted from one cell to the entire tool battery pack. It also ensures that the overall size of the tool battery pack does not become excessively large, allowing the tool battery pack design to be applied to existing tools and equipment while maintaining safety and performance.A standardized gap size makes the system easier and more efficient to operate during the production and assembly process.

[0199] It will be understood by those skilled in the art that the embodiments described above are merely exemplary and that numerous modifications in form and design may be made without departing from the spirit or scope of the present application. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 202520348339.4

[0001] CN 202520561968.5

[0001]

Claims

[1] A tool battery pack comprising a housing assembly, a cell assembly, a pole piece holder, and a control device, the housing assembly being for receiving the cell assembly, the pole piece holder, and the control device; the control device being connected to the pole piece holder and the cell assembly; the cell assembly comprising unit cells and a cell holder, the cell holder having an exposed hole, the end of the cell holder of the exposed hole being the cell assembly end face, characterized bythat it further comprises a barrier element with a heat-conducting effect, wherein the barrier element is arranged on a cell assembly end face by means of a positioning connector, wherein the cell assembly end face serves as a reference plane, wherein the barrier element has a first end face close to the reference plane and a second end face remote from the reference plane, wherein a distance G1 exists between the first end face and the cell assembly end face, wherein a pressure relief space is formed between the first end face and the cell assembly end face, wherein the pressure relief space has at least one pressure relief outlet. [2] Tool battery pack according to claim 1, characterized by that the distance G1 is greater than or equal to 1 mm and less than 10 mm. [3] Tool battery pack according to claim 1, characterized by that the barrier element consists of a rigid material with a flash point of 300°C or more. [4] Tool battery pack according to claim 1, characterized by that the barrier element is a metallic material and the distance G1 is greater than or equal to 1 mm and less than 10 mm. [5] Tool battery pack according to one of claims 2-4, characterized by that the unit cell has a cell end face and a cell main body, wherein the thickness J of the barrier element corresponding to the cell end face region is ≥0.8 mm and less than or equal to 3 mm. [6] Tool battery pack according to claim 5, characterized by in that the cell end face comprises a first cell end face and a second cell end face, wherein the cell assembly end face comprises at least 2 cell end faces, wherein the thickness of the barrier element corresponding to the area of ​​the first cell end face is less than or equal to 1 mm when subtracted from the thickness of the barrier element corresponding to the area of ​​the second cell end face. [7] Tool battery pack according to claim 6, characterized bythat the thickness of the barrier element corresponding to the area of ​​the first cell end face is equal to the thickness of the barrier element corresponding to the area of ​​the second cell end face. [8] Tool battery pack according to claim 6, characterized by that the thickness of the barrier element corresponding to the area of ​​the first cell end face is greater than the thickness of the barrier element corresponding to the area of ​​the second cell end face. [9] Tool battery pack according to claim 5, characterized by , that the first end face of the barrier element corresponding to the region of the cell end face has a convex structure remote from the reference plane, and / or that the second end face of the barrier element, which corresponds to the region of the cell end face, has a convex structure which is remote from the reference plane. [10] Tool battery pack according to claim 5, characterized bythat the first end face and the second end face of the barrier element, which correspond to the area of ​​the cell end face, are both flat. [11] Tool battery pack according to claim 1, characterized by that the pressure relief outlet is provided on the barrier element and / or the end face of the cell assembly and / or the cell holder, wherein the pressure relief outlet is provided on the surface of the pressure relief space between the first end face and the end face of the cell assembly. [12] Tool battery pack according to claim 1, characterized by that the pressure relief outlet is arranged at the end face of the barrier element between unit cells on the cell holder, which does not correspond to the area of ​​the cell end face. [13] Tool battery pack according to claim 1, characterized by that the projection area of ​​the end face of the barrier element is greater than or equal to the projection area of ​​the adjacent cell assembly end face. [14] Tool battery pack according to claim 1, characterized by that the projection area of ​​the end face of the barrier element is smaller than the projection area of ​​the adjacent cell assembly end face, wherein the projection area of ​​the barrier element is greater than or equal to the projection area of ​​the maximum outer size of all cell end faces of the cell assembly end face. [15] Tool battery pack according to claim 1, characterized by in that the housing assembly has a first cooling opening and a second cooling opening, wherein the first cooling opening is an air inlet while the second cooling opening is an air outlet, wherein the pressure relief air flow is discharged through the second cooling opening. [16] Tool battery pack according to claim 15, characterized by that the second cooling opening is at least one type of plastic and metal. [17] Tool battery pack according to claim 15, characterized bythat the second cooling opening further comprises a pressure relief valve. [18] A tool battery pack comprising a housing assembly, a cell assembly, a pole piece holder, and a control device, the housing assembly serving to receive the cell assembly, the pole piece holder, and the control device; the control device being connected to the pole piece holder and the cell assembly;wherein the cell assembly comprises unit cells, a cell holder, a first cell assembly, a second cell assembly, and a cell assembly connecting member for connecting the first cell assembly and the second cell assembly, wherein the cell holder has an exposed hole, wherein the end of the cell holder with the exposed hole is the cell assembly end face, wherein the first cell assembly comprises a first cell assembly end face and a second cell assembly end face, wherein the second cell assembly comprises a third cell assembly end face and a fourth cell assembly end face, wherein the third cell assembly end face is opposite the second cell assembly end face, ; characterized bythat it further comprises a barrier element, wherein the barrier element is arranged between the third cell assembly end surface and the second cell assembly end surface by means of a positioning connector, wherein the third cell assembly end surface serves as a reference plane, wherein the barrier element has a first end surface close to the reference plane and a second end surface remote from the reference plane, wherein a first pressure relief space is formed between the first end surface and the third cell assembly end surface, wherein a distance G1 exists between the first end surface and the third cell assembly end surface, wherein a second pressure relief space is formed between the second end surface and the second cell assembly end surface, wherein a distance G2 exists between the second end surface and the second cell assembly end surface, wherein the first pressure relief space and the second pressure relief space have at least one pressure relief outlet. [19] Tool battery pack according to claim 18, characterized by that the distance G1 is greater than or equal to 1 mm and less than 10 mm, and / or that the distance G2 is greater than or equal to 1 mm and less than 10 mm. [20] Tool battery pack according to claim 18, characterized by that the difference between the distance G1 and the distance G2 is less than or equal to 3 mm. [21] Tool battery pack according to claim 20, characterized by that the distance G1 is equal to the distance G2. [22] Tool battery pack according to claim 18, characterized by that the unit cell has a cell end face and a cell main body, wherein the thickness J of the barrier element corresponding to the cell end face region is greater than or equal to 0.8 mm and less than or equal to 3 mm. [23] Tool battery pack according to claim 18, characterized byin that the cell end face comprises a first cell end face and a second cell end face, wherein the cell assembly end face comprises at least 2 cell end faces, wherein the thickness of the barrier element corresponding to the area of ​​the first cell end face is less than or equal to 1 mm when subtracted from the thickness of the barrier element corresponding to the area of ​​the second cell end face. [24] Tool battery pack according to claim 23, characterized by that the thickness of the barrier element corresponding to the area of ​​the first cell end face is equal to the thickness of the barrier element corresponding to the area of ​​the second cell end face. [25] Tool battery pack according to claim 23, characterized by that the thickness of the barrier element corresponding to the area of ​​the first cell end face is greater than the thickness of the barrier element corresponding to the area of ​​the second cell end face. [26] Tool battery pack according to claim 22, characterized by , that the first end face of the barrier element corresponding to the region of the cell end face has a convex structure which is remote from the reference plane, and / or, that the second end face of the barrier element, which corresponds to the region of the cell end face, has a convex structure which is remote from the reference plane. [27] Tool battery pack according to claim 22, characterized by that the first end face and the second end face of the barrier element, which correspond to the area of ​​the cell end face, are both flat. [28] Tool battery pack according to claim 18, characterized by that the pressure relief outlet is provided on the barrier element and / or the end face of the cell assembly and / or the cell holder, wherein the pressure relief outlet is provided on the surface of the pressure relief space between the first end face and the end face of the cell assembly. [29] Tool battery pack according to claim 18, characterized bythat the pressure relief outlet is arranged on the end face of the barrier element between unit cells on the cell holder, which does not correspond to the area of ​​the cell end face. [30] Tool battery pack according to claim 18, characterized by that the projection area of ​​the end face of the barrier element is greater than or equal to the projection area of ​​the adjacent cell assembly end face. [31] Tool battery pack according to claim 18, characterized by , that the projection area of ​​the end face of the barrier element is smaller than the maximum projection area of ​​the adjacent cell assembly end face, wherein the shape of the barrier element is greater than or equal to the projection area of ​​all cell end faces of the adjacent cell assembly end faces when the projection area of ​​all cell end faces of the third cell assembly end faces is equal to the projection area of ​​all cell end faces of the second cell assembly end faces and their shapes match; or if the projection area of ​​all cell end faces of the third cell assembly end face is identical to the projection area of ​​all cell end faces of the second cell assembly end faces, but not positionally corresponding, or the projection area of ​​all cell end faces of the second cell assembly end faces is neither identical nor positionally corresponding, the projection area of ​​the end face of the barrier element is greater than or equal to the maximum projection area resulting from a union of the maximum projection area of ​​all cell end faces of the second cell assembly end faces and the maximum projection area of ​​all cell end faces of the third cell assembly end faces. [32] Tool battery pack according to one of claims 18-31, characterized byin that the housing assembly has a first cooling opening and a second cooling opening, wherein the first cooling opening is an air inlet while the second cooling opening is an air outlet, wherein the pressure relief air flow is discharged through the second cooling opening. [33] Tool battery pack according to one of claims 18-31, characterized by that the barrier element consists of a heat dissipation material with a flash point of 300°C or more. [34] Tool battery pack according to one of claims 18-31, characterized by that the barrier element consists of a rigid material with a flash point of 300°C or more. [35] Tool battery pack according to one of claims 18-31, characterized by that the barrier element is made of metal. [36] Tool battery pack according to claim 33, characterized by that the barrier element is made of a metal material with aluminum. [37] Tool battery pack according to claim 32, characterized by , that the second cooling opening is at least one type of plastic and metal 38. Tool battery pack according to claim 32, characterized by , that the second cooling opening further comprises a pressure relief valve.

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