Battery housing assembly, battery and battery pack

Abstract

The application relates to the technical field of batteries, and discloses a shell assembly of a battery, the battery and a battery pack, which comprise: a shell, which is enclosed to form a containing space, and has a first surface; a pole, which is arranged on the first surface; and an insulating piece, which is at least partially clamped between the shell and the pole; the insulating piece is made of a thermoplastic material; the overlapping area of the pole, the shell and the insulating piece in the orthographic projection on the first surface is S; the thermogravimetric loss rate of the insulating piece at 460 DEG C is A; and 1 mm2 / %<=S / A<=74 mm2 / % is met. The ratio of the thermogravimetric loss rate A of the insulating piece and the projection area S of the shell on the side of the pole away from the containing space is limited, the heat dissipation performance of the pole is ensured, the safety risks such as thermal runaway of the battery are avoided, the insulation effect of the insulating piece between the pole and the shell is ensured, the pole is prevented from moving and being dislocated, and the safety problems such as short circuit of the battery are avoided.

Description

[0001] This application is a divisional application of the invention patent application with publication number CN2025106045019. The original application was filed on May 12, 2025; the application number was 2025106045019; and the invention was entitled "Battery casing assembly, battery and battery pack". Technical Field

[0002] This invention relates to the field of battery technology, and more specifically to battery casing components, batteries, and battery packs. Background Technology

[0003] A battery typically comprises an internal structure and an external structure. The external structure includes a casing that encloses a housing space, while the internal structure includes a battery cell housed within this housing space. The external structure also includes terminals, which are disposed within the casing. The battery cell's tabs are electrically connected to these terminals to draw out the battery's charge. In existing technology, an insulating component is typically placed between the terminals and the casing. However, the heat generated during battery charging and discharging can easily cause this insulating component to melt. Furthermore, the compressive force applied by the terminals and casing can cause the molten insulating component to leak out, leading to insulation failure between the terminals and the casing. This can also cause the terminals to shift or misalign, potentially resulting in short circuits and other safety issues. Summary of the Invention

[0004] In view of this, the present invention provides a battery casing assembly, a battery, and a battery pack to solve the problem in the prior art that the insulating parts in the molten state are prone to overflow, which leads to insulation failure between the terminals and the casing, and can easily cause the terminals to move and misalign, which can easily cause safety problems such as battery short circuits.

[0005] In a first aspect, the present invention provides a battery casing assembly, comprising: a casing enclosing a receiving space, the casing having a first surface; an electrode post disposed on the first surface; and an insulating member at least partially sandwiched between the casing and the electrode post; the insulating member is a thermoplastic material, including one or more of polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, other polyolefins and their copolymers, polysulfone, and polyphenylene ether; the thickness of the insulating member sandwiched between the casing and the electrode post in a direction perpendicular to the first surface is h, satisfying 0.05mm≤h≤4mm; wherein the overlapping area of ​​the electrode post, the casing, and the insulating member projected onto the first surface is S, and the thermogravimetric loss rate of the insulating member at 460°C is A, satisfying 1 mm² / %≤S / A≤74mm² / .

[0006] Beneficial Effects: By limiting the thermogravimetric loss rate (A) of the insulator and the ratio of the overlapping area (S) of the electrode, casing, and insulator's orthographic projection on the first surface, the heat dissipation performance of the electrode is ensured, preventing safety risks such as thermal runaway. Simultaneously, the insulation effect of the insulator between the electrode and casing is guaranteed, preventing electrode displacement and short circuits. Specifically, if S / A > 74 mm² / %, when the casing covers the side of the electrode away from the receiving space, the covered area is too large, resulting in a small uncovered area on the side of the electrode away from the receiving space. This leads to poor heat dissipation, especially during high-rate fast charging, where the electrode generates significant heat, increasing the risk of thermal runaway. Alternatively, it can make the insulator too brittle, prone to cracking and insulation failure, causing short circuits and other safety risks. If S / A < 0.6 mm² / %, the insulation component will be subjected to excessive compressive force from the casing and the terminal, which may cause the insulation component to be squeezed out, resulting in gaps between the casing and the terminal. This can lead to misalignment of the insulation component and the terminal, potentially causing insulation failure and battery short circuits. Alternatively, it may result in poor thermosetting properties of the insulation component, making it prone to melting at high temperatures and overflowing under the compressive force of the casing and the terminal. This can also cause gaps between the casing and the terminal, leading to misalignment of the insulation component and the terminal, potentially causing insulation failure and battery short circuits. Furthermore, when the terminal is pressed against the first surface, the overall area of ​​the terminal will be small, resulting in poor heat dissipation. In particular, when the battery is fast-charged at high rates, the heat generated by the terminal is large, and the poor heat dissipation of the terminal increases the risk of thermal runaway.

[0007] In a second aspect, the present invention provides a battery, comprising: a casing assembly of the battery as described above; and a battery cell disposed in the receiving space, the battery cell comprising a battery cell body and a tab extending from an end of the battery cell body, the tab being electrically connected to the terminal post.

[0008] Thirdly, the present invention provides a battery pack comprising: the aforementioned batteries, wherein a plurality of the batteries are disposed; and a busbar welded to the side of at least two of the terminals of the batteries away from the receiving space. Attached Figure Description

[0009] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the overall structure of a battery according to an embodiment of the present invention; Figure 2 for Figure 1 A top view of the battery shown; Figure 3 for Figure 2 A cross-sectional view along the AA direction; Figure 4 for Figure 3 A magnified view of part B in the diagram; Figure 5 This is a schematic diagram of the overall structure of another battery according to an embodiment of the present invention; Figure 6 for Figure 5 A top view of the battery shown; Figure 7 for Figure 6 A cross-sectional view along the CC direction; Figure 8 for Figure 7 A magnified view of part of E in the diagram; Figure 9 for Figure 6 A cross-sectional view along the DD direction; Figure 10 for Figure 9 A magnified view of part of F; Figure 11 for Figure 5 A partial exploded view of the battery structure; Figure 12 This is a schematic diagram of the overall structure of another battery according to an embodiment of the present invention; Figure 13 for Figure 12 A top view of the battery shown; Figure 14 for Figure 13 Cross-sectional view along the GG direction; Figure 15 for Figure 14 A magnified view of part of H in the diagram; Figure 16 This is a schematic diagram of the structure of a shell according to an embodiment of the present invention; Figure 17 for Figure 4 The diagram shows the structure of the electrode and busbar being welded together.

[0011] Explanation of reference numerals in the attached figures: 1. Outer shell; 11. First surface; 12. Terminal hole; 13. Main body; 14. Protrusion; 141. Connecting edge; 142. Folded edge; 15. Shell; 151. Cover plate mating part; 152. Cell mating part; 16. Cover plate; 2. Terminal; 3. Insulating component; 4. Cell; 5. Sealing ring; 6. Busbar; 7. Welding area. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] The following is combined with Figures 1 to 17 The following describes embodiments of the present invention.

[0014] According to an embodiment of the present invention, in one aspect, a battery casing assembly is provided, comprising: a casing 1 enclosing a receiving space, the casing 1 having a first surface 11; an electrode post 2 disposed on the first surface 11; and an insulating member 3 at least partially sandwiched between the casing 1 and the electrode post 2; wherein the overlapping area of ​​the electrode post 2, the casing 1, and the insulating member 3 projected onto the first surface 11 is S, and the thermogravimetric loss rate of the insulating member 3 at 460°C is A, satisfying 0.6 mm² / % ≤ S / A ≤ 74 mm² / .

[0015] In this embodiment, by limiting the thermogravimetric loss rate A of the insulating component 3 and the ratio of the overlapping area S of the three components—the terminal post 2, the outer shell 1, and the insulating component 3—on the first surface 11, the heat dissipation performance of the terminal post 2 is guaranteed, and the safety risks such as thermal runaway of the battery are avoided. At the same time, the insulation effect of the insulating component 3 between the terminal post 2 and the outer shell 1 is guaranteed, and the displacement of the terminal post 2 is avoided, thus preventing safety problems such as battery short circuits.

[0016] Specifically, if S / A > 74 mm² / %, when the outer casing 1 covers the side of the terminal post 2 away from the housing space, the covered area is too large, resulting in the area of ​​the part of the terminal post 2 not covered by the outer casing 1 being too small. This leads to poor heat dissipation of the terminal post 2. In particular, when the battery is charged at a high rate, the heat generated by the terminal post 2 is large, and the poor heat dissipation of the terminal post 2 leads to a high risk of thermal runaway of the battery. Alternatively, it may make the insulation component 3 too brittle, which may easily cause the insulation component 3 to crack, thereby causing insulation failure and safety risks such as battery short circuit.

[0017] If S / A < 0.6 mm² / %, the insulating component 3 will be subjected to excessive compressive force from the outer casing 1 and the terminal post 2, which may cause the insulating component 3 to be squeezed out, resulting in gaps between the outer casing 1 and the terminal post 2. This can lead to the insulating component 3 and the terminal post 2 being prone to displacement and misalignment, easily causing insulation failure and battery short circuits. Alternatively, it may result in poor thermosetting properties of the insulating component 3, which may melt under high temperatures and overflow under the compressive force of the outer casing 1 and the terminal post 2. This can also lead to gaps between the outer casing 1 and the terminal post 2, causing the insulating component 3 and the terminal post 2 to be prone to displacement and misalignment, easily causing insulation failure and battery short circuits. Furthermore, when the terminal post is pressed onto the first surface, the overall area of ​​the terminal post will be small, resulting in poor heat dissipation. In particular, when the battery is charged at a high rate, the heat generated by the terminal post is large, and the poor heat dissipation of the terminal post leads to a high risk of thermal runaway.

[0018] Optionally, the value of S / A can be any one of the following: 0.6 mm² / %, 0.8 mm² / %, 1 mm² / %, 1.2 mm² / %, 2 mm² / %, 2.8 mm² / %, 3 mm² / %, 5 mm² / %, 8 mm² / %, 10 mm² / %, 12 mm² / %, 15 mm² / %, 18 mm² / %, 20 mm² / %, 22 mm² / %, 24 mm² / %, 28 mm² / %, 30 mm² / %, 32 mm² / %, 35 mm² / %, 38 mm² / %, 40 mm² / %, 42 mm² / %, 45 mm² / %, 48 mm² / %, 50 mm² / %, 52 mm² / %, 55 mm² / %, 58 mm² / %, 60 mm² / %, 62 mm² / %, 65 mm² / %, 68 mm² / %, 70 mm² / %, 72 mm² / %, 74 mm² / %.

[0019] It is worth noting that in related technologies, for high-rate fast-charging batteries, the overcurrent from cell 4 to terminal 2 is relatively large, resulting in significant heat generation at terminal 2. This can easily cause the insulating component 3, located between the outer casing 1 and terminal 2, to melt due to heat. Simultaneously, the insulating component 3 is subjected to compressive forces from the outer casing 1 and terminal 2, causing the molten insulating component 3 to be squeezed out, resulting in gaps between the outer casing 1 and terminal 2. This makes the insulating component 3 and terminal 2 prone to displacement and misalignment, leading to insulation failure between the outer casing 1 and terminal 2, and potentially causing battery short circuits and other safety issues. In this application, the thermogravimetric loss rate A of the insulating component 3 and the overlapping area S of the terminal 2, outer casing 1, and insulating component 3's orthogonal projections on the first surface 11 are in a suitable proportional relationship. This satisfies the heat dissipation performance of terminal 2 while ensuring the insulating component 3 remains stably positioned between the outer casing 1 and terminal 2, preventing insulation failure and battery short circuits, and improving battery safety.

[0020] It should be noted that, in the direction perpendicular to the first surface 11, the outer shell 1, the pole post 2, and the insulating member 3 all have projections on the first surface 11, and the projections of the three overlap.

[0021] It's important to note that thermogravimetric analysis (TGA) is a widely used technique in materials science, chemistry, and environmental science. By measuring how the mass of a substance changes with temperature or temperature variations, it's possible to understand the substance's composition, structure, properties, and reaction processes. Weight loss rate is a crucial parameter in TGA, reflecting the evaporation loss of a substance at high temperatures. It's essential for understanding a substance's thermal stability and reactivity. Specifically, TGA measures the relationship between a substance's mass and temperature or temperature variations under programmed temperature control. TGA allows observation of the evaporation process, the phenomenon of a substance losing mass at high temperatures. This process can be due to the weakening of intermolecular forces caused by molecular thermal motion, leading to molecules detaching from the substance's surface; or it can be due to the breaking of chemical bonds, causing the substance to decompose. In TGA, the weight loss rate refers to the proportion of mass lost by a substance at high temperatures relative to its original mass. The magnitude of the weight loss rate reflects the substance's tendency to volatilize at high temperatures and is an important indicator for evaluating a material's thermal stability and reactivity.

[0022] It is worth noting that in this embodiment, the outer casing 1 has a pole hole 12 on the wall where the first surface 11 is located, and the pole 2 is at least partially inserted into the pole hole 12.

[0023] In one embodiment, the overlapping area S of the orthographic projections of the electrode post 2, the outer casing 1, and the insulating component 3 onto the first surface 11 satisfies 10mm² ≤ S ≤ 150mm². This configuration ensures the heat dissipation performance of the electrode post 2 while preventing the insulating component 3 from being squeezed out, thus guaranteeing the insulation effect of the insulating component 3 and preventing safety issues such as battery short circuits.

[0024] It is worth noting that if S > 150 mm², when the outer casing 1 covers the side of the terminal post 2 away from the housing space, the covered area is too large, resulting in the area of ​​the part of the terminal post 2 not covered by the outer casing 1 being too small. This leads to poor heat dissipation of the terminal post 2. In particular, when the battery is charged at a high rate, the heat generated by the terminal post 2 is large, and the poor heat dissipation of the terminal post 2 leads to a high risk of thermal runaway of the battery. On the other hand, if the terminal post 2 is to have sufficient heat dissipation area, the area of ​​the side of the terminal post 2 away from the housing space needs to be increased, which will lead to an increase in the overall volume of the terminal post 2. This will not only affect the space utilization and energy density of the battery, but also affect the arrangement of other components (such as explosion-proof valve, liquid injection hole, etc.) on the first surface 11 of the outer casing 1. If S < 10mm², the insulating component 3 will be subjected to excessive compressive force from the outer shell 1 and the terminal post 2, which may cause the insulating component 3 to be squeezed out, resulting in a gap between the outer shell 1 and the terminal post 2. This may cause the insulating component 3 and the terminal post 2 to move and misalign, which may lead to insulation failure and battery short circuit. Furthermore, when the terminal post is pressed against the first surface, the overall area of ​​the terminal post will be small, which will also result in poor heat dissipation. In particular, when the battery is fast charged at a high rate, the heat generated by the terminal post is large and the heat dissipation effect of the terminal post is poor, resulting in a high risk of thermal runaway of the battery.

[0025] Optionally, S can be any value from 10mm², 20mm², 30mm², 40mm², 50mm², 60mm², 70mm², 80mm², 90mm², 100mm², 110mm², 120mm², 130mm², 140mm², 150mm², or a value between any two of these values.

[0026] In one embodiment, the thermogravimetric loss rate A of the insulating component 3 at 460°C satisfies 2% ≤ A ≤ 18%. This setting ensures that the insulating component 3 has good heat resistance while avoiding excessive brittleness, thereby improving the reliability of the insulating component 3, preventing insulation failure, and enhancing the safety performance of the battery.

[0027] It is worth noting that if A > 18%, the thermosetting properties of the insulating component 3 will be poor. When the insulating component 3 is subjected to high temperature, it is easy to melt and overflow under the extrusion force of the outer shell 1 and the terminal 2. This will also cause gaps between the outer shell 1 and the terminal 2, making the insulating component 3 and the terminal 2 prone to displacement and misalignment, which can easily lead to insulation failure and battery short circuit. If A < 2%, the insulating component 3 will be too brittle, which can easily cause the insulating component 3 to crack, leading to insulation failure and causing safety risks such as battery short circuit.

[0028] Optionally, A can be any value from 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or a value between any two values.

[0029] In one embodiment, such as Figure 3 and Figure 7 As shown, the outer casing 1 includes a housing 15 and a cover plate 16. The housing 15 has at least one opening, and the cover plate 16 is connected to the housing 15 and seals the opening. The housing 15 and the cover plate 16 enclose and form an accommodating space. Furthermore, the surface of the cover plate 16 or the surface of the housing 15 can serve as the first surface 11, that is, the pole post can be disposed on the cover plate 16 or on the housing 15.

[0030] In the first implementation, such as Figure 4 , Figure 8 and Figure 10 As shown, the outer casing 1 includes a main body 13 and a protrusion 14. The protrusion 14 is disposed on the first surface 11 and forms a flange to fasten to the side of the pole post 2 away from the receiving space. The insulating member 3 is at least partially disposed between the side of the pole post 2 away from the receiving space and the side of the protrusion 14 near the receiving space. Specifically, when the pole post hole 12 is opened on the cover plate 16, the main body 13 is the plate main body 13; when the pole post hole 12 is opened on the housing 15, the main body 13 is the housing main body 13.

[0031] Furthermore, such as Figure 4 , Figure 8 and Figure 10 As shown, the protrusion 14 includes a connecting edge 141 and a folded edge 142. The side of the connecting edge 141 closest to the receiving space is fixedly connected to the main body 13, and the side of the connecting edge 141 furthest from the receiving space is fixedly connected to the side of the folded edge 142. The folded edge 142 is set at a predetermined angle to the connecting edge 141 so that the folded edge 142 at least partially covers the side of the pole post 2 furthest from the receiving space.

[0032] It is worth noting that in this embodiment, the protrusion 14 has an annular structure. Specifically, both the connecting edge 141 and the folded edge 142 have an annular structure and are continuously arranged along the circumference of the pole post hole 12. It can be understood that the folded edge 142 is continuously arranged along the circumference of the side of the pole post 2 away from the receiving space. Therefore, in the direction perpendicular to the first surface 11, the projection of the folded edge 142 on the side of the pole post 2 away from the receiving space is annular, and the projected area is the annular area.

[0033] It should be further explained that the side of the pole post 2 away from the receiving space can be a circular surface or a square surface; correspondingly, the projection of the folded edge 142 on the side of the pole post 2 away from the receiving space can be a circular ring or a square ring.

[0034] Of course, as an alternative implementation, the side of the pole post 2 away from the receiving space can also be other regular or irregular shapes. Correspondingly, the projection of the folded edge 142 on the side of the pole post 2 away from the receiving space should match the shape of that side. In addition, the connecting edge 141 and / or the folded edge 142 can also be discontinuously arranged along the circumference of the pole post hole 12, as long as they can cooperate with the pole post 2 to provide compressive force to the insulating member 3.

[0035] In one embodiment, such as Figure 4 , Figure 8 and Figure 10 As shown, at least a portion of the insulating element 3 is located between the outer casing 1 and the peripheral surface of the pole 2. Specifically, in one embodiment, as... Figure 4 As shown, the insulating element 3 is located between the surface of the protrusion 14 and the pole post 2; in another embodiment, as Figure 8 and Figure 10 As shown, the insulating member 3 is provided to cover the protrusion 14. That is, not only is the insulating member 3 provided between the surface of the protrusion 14 and the pole post 2, but the side of the protrusion 14 away from the pole post 2 is also provided with the insulating member 3.

[0036] In one embodiment, see Figures 5 to 11The protrusion 14 is welded to the main body 13, satisfying 0.6 mm² / %≤S / A≤72 mm² / %. That is, the protrusion 14 and the main body 13 are separate components, and the protrusion 14 is then fixedly connected to the main body 13 by welding. At this point, the connection strength between the protrusion 14 and the main body 13 is relatively weak, and the compressive force exerted on the insulating component 3 by the protrusion 14 and the electrode post 2 is relatively small, making it less likely for the insulating component 3 to be extruded. Therefore, when the thermogravimetric loss rate of the insulating component 3 is constant, the area of ​​the outer shell 1 covering the side of the electrode post 2 away from the receiving space can be relatively reduced. This not only ensures that the insulating component 3 is stably positioned between the outer shell 1 and the electrode post 2, thus guaranteeing the insulation effect of the insulating component 3 and preventing safety issues such as battery short circuits, but also further increases the area of ​​the uncovered portion of the electrode post 2, improving the heat dissipation effect of the electrode post 2, reducing the risk of thermal runaway of the battery, and improving the safety performance of the battery. Alternatively, when the area of ​​the outer shell 1 covering the side of the pole 2 away from the receiving space is fixed, the thermogravimetric loss rate of the insulating component 3 can be relatively increased. While avoiding cracking of the insulating component 3, the relatively small compressive force will also prevent the insulating component 3 from being squeezed out.

[0037] In one embodiment, see Figures 1 to 4 The protrusion 14 is integrally formed with the main body 13, satisfying 0.8 mm² / % ≤ S / A ≤ 74 mm² / %. For example, the main body 13 and the protrusion 14 can be integrally formed by stamping. In this case, the connection strength between the protrusion 14 and the main body 13 is relatively high, and the compressive force exerted on the insulating component 3 by the protrusion 14 and the terminal post 2 is relatively large, making the insulating component 3 more likely to be extruded, leading to insulation failure and battery short circuit. Therefore, when the thermogravimetric loss rate of the insulating component 3 is constant, the area of ​​the outer shell 1 covering the side of the terminal post 2 away from the receiving space can be relatively increased, thereby reducing the pressure on the insulating component 3, preventing the insulating component 3 from being extruded, ensuring the insulation effect of the insulating component 3, and avoiding safety problems such as battery short circuit. Alternatively, when the area of ​​the outer shell 1 covering the side of the terminal post 2 away from the receiving space is constant, the thermogravimetric loss rate of the insulating component 3 can be relatively reduced, thereby enabling the insulating component 3 to have better thermosetting properties when heated, preventing the insulating component 3 from melting and being extruded.

[0038] In one embodiment, the protrusion 14 is made of steel, satisfying 0.8 mm² / % ≤ S / A ≤ 74 mm² / %. It is worth noting that the steel protrusion 14 has high strength, resulting in greater compressive force on the insulating component 3 from both the protrusion 14 and the terminal post 2. This makes the insulating component 3 more susceptible to extrusion, potentially leading to insulation failure and battery short circuits. Therefore, when the thermogravimetric loss rate of the insulating component 3 is constant, the area of ​​the outer casing 1 covering the side of the terminal post 2 away from the receiving space can be relatively increased, thereby reducing the pressure on the insulating component 3, preventing it from being extruded, ensuring its insulation effect, and avoiding safety issues such as battery short circuits. Alternatively, when the area of ​​the outer casing 1 covering the side of the terminal post 2 away from the receiving space is constant, the thermogravimetric loss rate of the insulating component 3 can be relatively reduced, allowing the insulating component 3 to have better thermosetting properties when heated, preventing it from melting and being extruded.

[0039] In another embodiment, the protrusion 14 is made of aluminum, satisfying 0.6 mm² / % ≤ S / A ≤ 72 mm² / %. It is worth noting that the aluminum protrusion 14 has lower strength, resulting in less compressive force on the insulating member 3 from the protrusion 14 and the terminal post 2, making it less prone to extrusion. Therefore, when the thermogravimetric loss rate of the insulating member 3 is constant, the area of ​​the outer shell 1 covering the side of the terminal post 2 away from the receiving space can be relatively reduced. This not only ensures the insulating member 3 remains stably positioned between the outer shell 1 and the terminal post 2, thus guaranteeing its insulation effect and preventing safety issues such as battery short circuits, but also further increases the area of ​​the uncovered portion of the terminal post 2, improving its heat dissipation, reducing the risk of thermal runaway, and enhancing battery safety. Alternatively, when the area of ​​the outer shell 1 covering the side of the terminal post 2 away from the receiving space is constant, the thermogravimetric loss rate of the insulating member 3 can be relatively increased. This avoids cracking of the insulating member 3 while preventing extrusion due to the relatively small compressive force.

[0040] In the second implementation, such as Figures 12 to 15 As shown, the pole post 2 is at least partially pressed onto the first surface 11, and the insulating member 3 is at least partially disposed between the first surface 11 and the side of the pole post 2 near the receiving space. That is, the pole post 2 is connected to the outer shell 1 by a press-fitting method, which makes the structure simpler and the manufacturing cost lower.

[0041] In one embodiment, the insulating element 3 is a thermosetting material. Furthermore, the overlapping area S of the pole post 2, the outer shell 1, and the insulating element 3 projected onto the first surface 11 satisfies the thermogravimetric loss rate A of the insulating element 3 at 460°C: 0.6 mm² / % ≤ S / A ≤ 70 mm² / %.

[0042] It is worth noting that thermosetting materials do not easily melt at high temperatures, which reduces the impact of high-temperature environments on the insulating component 3. Therefore, under the influence of heat generated during the overcurrent process of the terminal post 2, the insulating component 3 is prevented from melting, ensuring its insulation effect and the battery's safety performance. At this point, even if the overlap area between the outer casing 1, the terminal post 2, and the insulating component is relatively small, resulting in relatively large compressive forces on the insulating component 3, it will not cause the insulating component 3 to be extruded. Simultaneously, it further increases the heat dissipation area of ​​the terminal post 2, improving its heat dissipation effect, reducing the risk of thermal runaway, and enhancing the battery's safety performance.

[0043] It's worth noting that thermosetting materials, such as thermosetting plastics, are plastics formed by cross-linking and curing through a process where thermosetting resins are the main component, along with various necessary additives. They are liquid in the early stages of manufacturing or molding; once cured, they are insoluble and infusible, and cannot be re-melted or softened. Thermosetting plastics soften and flow upon initial heating, but upon reaching a certain temperature, a chemical reaction (cross-linking reaction) occurs, causing them to harden and solidify. This change is irreversible; thereafter, reheating will not allow them to soften and flow again. Molding is achieved by utilizing this characteristic, taking advantage of the plasticizing flow during the initial heating to fill the mold cavity under pressure, and then curing into a product of a specific shape and size. Common thermosetting plastics include phenolic plastics, epoxy plastics, amino plastics, unsaturated polyesters, and alkyd plastics.

[0044] In one embodiment, the insulating element 3 is made of thermoplastic material. Furthermore, the overlapping area S of the pole post 2, the outer shell 1, and the insulating element 3 projected onto the first surface 11 satisfies the thermogravimetric loss rate A of the insulating element 3 at 460°C: 1 mm² / % ≤ S / A ≤ 74 mm² / %.

[0045] It is worth noting that thermoplastic materials can make the insulating component 3 less brittle, preventing it from cracking under compressive stress. However, thermoplastic materials are easily affected by high temperatures and may melt. Therefore, by relatively increasing the overlapping area between the outer shell 1 and the pole 2 and the insulating component, the compressive stress on the insulating component 3 is relatively reduced, preventing the insulating component 3 from being squeezed out.

[0046] It should be noted that thermoplastic materials, such as thermoplastic plastics, refer to plastics that soften when heated and harden when cooled. Thermoplastic plastics are formulated primarily with thermoplastic resins and various additives. Under certain temperature conditions, the plastic can soften or melt into any shape, and retain its shape upon cooling; this process can be repeated multiple times while maintaining plasticity, and this repetition is merely a physical change. Common thermoplastic plastics include polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, other polyolefins and their copolymers, polysulfone, and polyphenylene ether.

[0047] In one embodiment, such as Figure 4 , Figure 8 and Figure 10 As shown, in the direction perpendicular to the first surface 11, the thickness of the insulating member 3 sandwiched between the outer casing 1 and the terminal post 2 is h, satisfying 0.05mm≤h≤4mm. This configuration ensures sufficient creepage distance between the outer casing 1 and the terminal post 2 to guarantee insulation, while preventing the insulating member 3 from failing and causing a large gap between the outer casing 1 and the terminal post 2, which could lead to misalignment of the insulating member 3 and the terminal post 2 and cause battery short circuits.

[0048] It is worth noting that if h > 4 mm, the thickness of the insulating component 3 located between the outer casing 1 and the side of the terminal 2 furthest from the accommodating space is too large, resulting in excessive material consumption for the insulating component 3 and wasting production costs. Simultaneously, the excessive volume occupied by the insulating component 3 reduces battery space utilization and affects the battery's energy density. To ensure battery energy density, the thickness of the outer casing 1 (specifically the folded edge 142) and / or the terminal 2 in the direction perpendicular to the first surface 11 needs to be reduced, weakening the battery's structural strength. Furthermore, when the insulating component 3 melts or cracks, leading to insulation failure, a large gap will be created between the outer casing 1 and the terminal 2, making them prone to displacement and misalignment, potentially causing battery short circuits. If h < 0.05 mm, the creepage distance between the outer casing 1 and the terminal 2 is too short, resulting in poor insulation of the insulating component 3 and a higher risk of battery short circuits.

[0049] Optionally, the value of h can be any value from 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, or a value between any two values.

[0050] In one embodiment, such as Figure 4 , Figure 8 and Figure 10 As shown, the battery casing assembly also includes a sealing ring 5, which is compressed and positioned between the casing 1 and the terminal 2. The sealing ring 5 ensures a tight seal between the casing 1 and the terminal 2.

[0051] It is worth noting that in this embodiment, by limiting the thermogravimetric loss rate A of the insulating component 3 and the ratio of the overlapping area S of the pole post 2, the outer shell 1 and the orthographic projection of the insulating component 3 on the first surface 11, the melting, cracking and extrusion of the insulating component 3 between the outer shell 1 and the pole post 2 are avoided, thereby preventing gaps between the outer shell 1 and the pole post 2, preventing the pole post 2 from moving or misaligning, and thus preventing misalignment between the sealing ring 5 and the pole post 2, thereby avoiding the occurrence of sealing failure and ensuring the sealing effect.

[0052] In one embodiment, the outer shell 1 is cylindrical, satisfying 10mm²≤S≤50mm², and 0.6 mm² / %≤S / A≤24mm² / .

[0053] In another embodiment, the outer shell 1 is a quadrangular prism shape, satisfying 50mm²≤S≤150mm², and 2.8 mm² / %≤S / A≤74 mm² / .

[0054] It is worth noting that when the outer casing 1 is cylindrical, the corresponding battery is a cylindrical battery; when the outer casing 1 is prismatic, the corresponding battery is a prismatic battery.

[0055] According to an embodiment of the present invention, in another aspect, a battery is provided, comprising: the casing assembly of the battery described above; and a battery cell 4 disposed in a receiving space, the battery cell 4 including a battery cell 4 body and a tab extending from an end of the battery cell 4 body, the tab being electrically connected to a terminal post 2.

[0056] In one embodiment, the terminal post 2 is disposed on the cover plate 16, satisfying 1 mm² / % ≤ S / A ≤ 74 mm² / %. It is worth noting that the cover plate 16 and the housing 15 are welded together. The housing 15 provides relatively poor constraint on the cover plate 16, and both the cover plate 16 and the terminal post 2 are at risk of deformation. This makes the insulating component 3 more susceptible to extrusion, potentially leading to insulation failure and battery short circuits. Therefore, when the thermogravimetric loss rate of the insulating component 3 is constant, the overlapping area between the housing 1, the terminal post 2, and the insulating component can be relatively increased, thereby reducing the pressure on the insulating component 3, preventing it from being extruded, ensuring its insulation effect, and avoiding safety issues such as battery short circuits. Alternatively, when the overlapping area between the housing 1, the terminal post 2, and the insulating component is constant, the thermogravimetric loss rate of the insulating component 3 can be relatively reduced, allowing the insulating component 3 to have better thermosetting properties when heated, preventing it from melting and being squeezed out.

[0057] Furthermore, such as Figure 16As shown, the housing 15 includes a cover plate mating portion 151 that encloses to form an opening and a cell mating portion 152 that encloses to form an accommodating space. The wall thickness of the housing 15 at the cover plate mating portion 151 is greater than the wall thickness at the cell mating portion 152. Therefore, when the cover plate 16 and the housing 15 are welded at the cover plate mating portion 151, a larger weld penetration can be achieved, enhancing the connection strength between the cover plate 16 and the housing 15, improving the restraining effect of the housing 15 on the cover plate 16, reducing the risk of deformation of the cover plate 16 and the electrode post 2, and further reducing the possibility of the insulating component 3 being extruded.

[0058] It is worth noting that, please refer to Figure 16 The wall thickness of the cover plate mating part 151 is t1, and the wall thickness of the cell mating part 152 is t2, satisfying t1>t2.

[0059] In another embodiment, the terminal post 2 is disposed on the housing 15, satisfying 0.6 mm² / % ≤ S / A ≤ 70 mm² / %. That is, the terminal post 2 is disposed on at least one side wall of the housing 15. It is worth noting that one side wall of the housing 15 and its adjacent other walls are usually integrally formed. Therefore, the overall structural strength of the housing 15 is high and it is not easy to deform, making it less likely for the insulating component 3 to be extruded. Therefore, when the thermogravimetric loss rate of the insulating component 3 is constant, the overlapping area of ​​the housing 1 and the terminal post 2 with the insulating component can be relatively reduced. At this time, it can not only ensure that the insulating component 3 is stably positioned between the housing 1 and the terminal post 2, thereby ensuring the insulation effect of the insulating component 3 and avoiding safety problems such as battery short circuits, but also further increase the heat dissipation area of ​​the terminal post 2, improve the heat dissipation effect of the terminal post 2, reduce the risk of thermal runaway of the battery, and improve the safety performance of the battery. Alternatively, when the overlapping area of ​​the outer shell 1 and the pole 2 with the insulating component is constant, the thermogravimetric loss rate of the insulating component 3 can be relatively increased. While avoiding cracking of the insulating component 3, the relatively small compressive force will also prevent the insulating component 3 from being squeezed out.

[0060] It should be noted that, for the battery in this embodiment, the outer casing 1 can be made of aluminum or steel or other metals; the battery can be a cylindrical battery, a prismatic battery, or a hexagonal prism battery.

[0061] According to an embodiment of the present invention, in another aspect, a battery pack is provided, comprising: the aforementioned battery, wherein a plurality of batteries are provided; and a busbar 6, which is welded to the side of the terminal post 2 of at least two batteries away from the receiving space.

[0062] The battery pack in this embodiment uses the battery described above. In the battery casing assembly, by limiting the ratio of the thermogravimetric loss rate A of the insulator and the overlapping area S of the three components—the terminals, the casing, and the insulator—on the first surface, the overcurrent capacity of the terminals and the busbar is guaranteed, and safety risks such as thermal runaway of the battery are avoided. At the same time, the insulation effect of the insulator between the terminals and the casing is guaranteed, and the displacement of the terminals is prevented, thus avoiding safety problems such as battery short circuits.

[0063] Specifically, if S / A > 74 mm² / %, when the casing covers the side of the terminal post furthest from the housing space, the covered area is too large, resulting in a small area (the area not covered by the casing) for welding the terminal post to the busbar. This leads to poor current carrying capacity of the terminal post and busbar, failing to meet the current carrying capacity requirements of the terminal post, affecting the overall charge and discharge rate of the battery. Furthermore, when the battery is fast charged at a high rate, the heat generated by the terminal post and busbar is large, and the heat dissipation effect of the terminal post is poor, resulting in a high risk of thermal runaway. Alternatively, it may make the insulation components too brittle, easily causing them to crack and leading to insulation failure, resulting in safety risks such as battery short circuits.

[0064] If S / A < 0.6 mm² / %, the insulation component will be subjected to excessive compressive force from the casing and terminals, which can easily cause the insulation component to be squeezed out, resulting in gaps between the casing and terminals. This can lead to misalignment of the insulation component and terminals, potentially causing insulation failure and battery short circuits. Alternatively, it can result in poor thermosetting properties of the insulation component, making it prone to melting at high temperatures and overflowing under the compressive force of the casing and terminals. This can also cause gaps between the casing and terminals, leading to misalignment of the insulation component and terminals, potentially causing insulation failure and battery short circuits. Furthermore, when the terminals are pressed onto the first surface, the overall area of ​​the terminals will be small, resulting in insufficient area for welding to the busbar. This leads to poor current carrying capacity of the terminals and busbar, failing to meet the current carrying capacity requirements of the terminals and affecting the overall charge and discharge rate of the battery. Moreover, when the battery is fast-charged at high rates, the heat generated by the terminals and busbar is large, and the heat dissipation effect of the terminals is poor, resulting in a high risk of thermal runaway.

[0065] It is worth noting that welding the terminal 2 to the busbar 6 can easily cause the insulating component 3 to melt due to heat. Therefore, in this embodiment, by limiting the thermogravimetric loss rate A of the insulating component 3 and the ratio of the overlapping area S of the terminal 2, the outer casing 1, and the orthographic projection of the insulating component 3 on the first surface 11, it is possible to ensure the current carrying capacity of the terminal 2 and the busbar 6, avoid safety risks such as thermal runaway of the battery, prevent the insulating component 3 from melting due to heat, ensure the reliability of the insulating component 3 between the terminal 2 and the outer casing 1, ensure the insulation effect of the insulating component 3 between the terminal 2 and the outer casing 1, prevent the terminal 2 from shifting or misaligning, and avoid safety problems such as battery short circuits.

[0066] In the first embodiment of the battery casing assembly, the overlapping area S of the three components—the terminal post 2, the casing 1, and the insulator 3—projected onto the first surface 11 and the thermogravimetric loss rate A of the insulator 3 at 460°C, satisfies 1.2 mm² / % ≤ S / A ≤ 74 mm² / %. It is worth noting that in the first embodiment of the battery casing 1 assembly, the insulator 3 receives a significant amount of heat during the welding of the terminal post 2 and the busbar 6, increasing the risk of melting. Therefore, by further restricting the value of S / A, the compressive force exerted on the insulator 3 by the casing 1 and the terminal post 2 is further reduced, and / or the thermosetting properties of the insulator 3 are further improved. This further ensures the reliability of the insulator 3 between the terminal post 2 and the casing 1, guarantees the insulation effect of the insulator 3 between the terminal post 2 and the casing 1, prevents the terminal post 2 from shifting or misaligning, and avoids safety issues such as battery short circuits.

[0067] In one embodiment, such as Figure 17 As shown, the electrode post 2 and the busbar 6 are welded to form a welding area 7. On a cross-section perpendicular to the first surface 11, the minimum distance between the edge of the welding area 7 and the edge of the insulating component 3 is d, which satisfies 0.4mm≤d≤18mm. This configuration ensures the current carrying capacity of the electrode post 2 and the busbar 6 while reducing the risk of the insulating component 3 melting due to heat.

[0068] It is worth noting that if d > 18 mm, the distance between the edge of the welding area 7 and the edge of the insulating component 3 is too large, which will result in the area of ​​the welding area 7 being too small, leading to poor current carrying capacity of the terminal 2 and busbar 6, failing to meet the current carrying capacity requirements of the terminal 2, and affecting the overall charge and discharge rate of the battery. On the other hand, if the welding area 7 is to have sufficient area, the overall volume of the terminal 2 will be too large, resulting in reduced space utilization of the battery and affecting the layout of other components on the casing 1. If d < 0.4 mm, the welding area 7 and the insulating component 3 are too close, and the insulating component 3 is greatly affected by the welding heat of the terminal 2 and busbar 6, increasing the risk of the insulating component 3 melting due to heat, and affecting the reliability of the insulating component 3 between the casing 1 and the terminal 2.

[0069] Optionally, d can be any value from 0.4mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, or a value between any two values.

[0070] The following tests were conducted on batteries with different S / A values. The test results for the example batteries and comparative batteries are shown in Table 1. The example batteries are those whose S / A values ​​meet the requirements of this example, while the comparative batteries are those whose S / A values ​​do not meet the requirements of this example.

[0071] Table 1 Battery Test Results

[0072] As can be seen from Table 1, in Examples 1 to 8, the value of S / A satisfies 0.6 mm² / %≤S / A≤74 mm² / %. Therefore, the battery heat dissipation performance test and insulation performance test of Examples 1 to 8 are all qualified.

[0073] As can be seen from Table 1, in Comparative Example 1, the value of S / A is greater than 74 mm² / %, that is, the value of S / A is too large, which leads to the failure of the battery heat dissipation performance test of Comparative Example 1.

[0074] As can be seen from Table 1, in Comparative Example 2, the value of S / A is less than 0.6 mm² / %, that is, the value of S / A is too small, which leads to the failure of the battery insulation performance test in Comparative Example 2.

[0075] The following sections introduce the methods for testing thermogravimetric loss rate, heat dissipation performance, and insulation performance.

[0076] (a) Test method for thermogravimetric loss rate A: A sample weighing 0.4 mg was obtained and tested using a NETZSCH thermogravimetric analyzer. The initial temperature was set to 40℃, and the temperature was increased to 460℃ at a rate of 10℃ / min. The thermogravimetric loss rate A of the sample was then obtained.

[0077] (II) Test methods for heat dissipation performance: The lithium-ion batteries prepared in the examples and comparative examples were tested at 25°C according to the following procedure.

[0078] For lithium iron phosphate batteries: 1) Connect the electrode to the temperature sensor, charge it at a constant current rate of 4C to 3.65V, and charge it at a constant voltage until the current drops to 0.05C. Record the temperature of the electrode area during the charging process. 2) Obtain the highest temperature T in the terminal area during charging. If the highest temperature T in the terminal area is ≤ 65℃, it is considered qualified; if T > 65℃, it is considered unqualified.

[0079] For ternary lithium batteries: 1) Connect the electrode to the temperature sensor, charge it at a constant current rate of 4C to 4.25V, and charge it at a constant voltage until the current drops to 0.05C. Record the temperature of the electrode area during the charging process. 2) Obtain the highest temperature T in the terminal area during charging. If the highest temperature T in the terminal area is ≤55℃, it is qualified; if T >55℃, it is unqualified.

[0080] (III) Test methods for insulation performance: The lithium-ion batteries prepared in the examples and comparative examples were subjected to cycle tests at 25°C according to the following procedure.

[0081] For lithium iron phosphate batteries: 1) Charge at a constant current rate of 1C to 3.65V, and then charge at a constant voltage until the current drops to 0.05C; 2) Let it stand for 30 minutes; 3) Discharge to 2.5V at a 1C rate; 4) Let it stand for 30 minutes; Perform 20 cycles following steps 1)-4). Set the alarm current value of the withstand voltage tester to 0.1mA and the voltage between the two output terminals to 1kV. Electrically connect the two output terminals of the withstand voltage tester to the battery casing and terminals respectively, and apply the set voltage values. If the withstand voltage tester alarms, it indicates a short circuit between the terminals and the casing, and the insulation performance is unqualified; if the withstand voltage tester does not alarm, it indicates no short circuit between the terminals and the casing, and the insulation performance is qualified.

[0082] For ternary lithium batteries: 1) Charge at a constant current rate of 1C to 4.35V, and then charge at a constant voltage until the current drops to 0.05C; 2) Let it stand for 20 minutes; 3) Discharge to 2.75V at a 1C rate; 4) Let it stand for 20 minutes; Perform 20 cycles following steps 1)-4). Set the alarm current value of the withstand voltage tester to 0.1mA and the voltage between the two output terminals to 1kV. Electrically connect the two output terminals of the withstand voltage tester to the battery casing and terminals respectively, and apply the set voltage values. If the withstand voltage tester alarms, it indicates a short circuit between the terminals and the casing, and the insulation performance is unqualified; if the withstand voltage tester does not alarm, it indicates no short circuit between the terminals and the casing, and the insulation performance is qualified.

[0083] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery casing assembly, characterized in that, include: The outer shell (1) is enclosed to form a receiving space, and the outer shell (1) has a first surface (11). A pole post (2) is disposed on the first surface (11); An insulating element (3) is at least partially sandwiched between the outer casing (1) and the pole post (2); The insulating component (3) is a thermoplastic material, which includes one or more of polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, other polyolefins and their copolymers, polysulfone, and polyphenylene ether. In the direction perpendicular to the first surface (11), the thickness of the insulating member (3) sandwiched between the outer shell (1) and the pole post (2) is h, which satisfies 0.05mm≤h≤4mm; The overlapping area of ​​the pole post (2), the outer shell (1) and the insulating component (3) on the first surface (11) is S, and the thermogravimetric loss rate of the insulating component (3) at 460℃ is A, which satisfies 1 mm² / %≤S / A≤74 mm² / .

2. The battery casing assembly according to claim 1, characterized in that, The overlapping area S of the orthographic projections of the pole post (2), the outer shell (1), and the insulating component (3) onto the first surface (11) satisfies 10mm²≤S≤150mm².

3. The battery casing assembly according to claim 1, characterized in that, The thermogravimetric loss rate A of the insulating component (3) at 460℃ satisfies 2%≤A≤18%.

4. The battery casing assembly according to any one of claims 1 to 3, characterized in that, The battery housing assembly also includes a sealing ring (5), which is compressed and disposed between the housing (1) and the terminal post (2).

5. The battery casing assembly according to any one of claims 1 to 3, characterized in that, The outer shell (1) is cylindrical and satisfies 10mm²≤S≤50mm².

6. The battery casing assembly according to any one of claims 1 to 3, characterized in that, The outer shell (1) is a quadrangular prism, satisfying 50mm²≤S≤150mm².

7. A battery, characterized in that, include: The housing assembly of the battery according to any one of claims 1 to 6; A battery cell (4) is disposed in the accommodating space. The battery cell (4) includes a battery cell (4) body and a tab extending from the end of the battery cell (4) body. The tab is electrically connected to the pole post (2).

8. The battery according to claim 7, characterized in that, The outer casing (1) includes a housing (15) and a cover plate (16), the housing (15) having at least one opening, the cover plate (16) being connected to the housing (15) and sealing the opening, the housing (15) and the cover plate (16) enclosing to form the receiving space.

9. The battery according to claim 8, characterized in that, The pole post (2) is disposed on the cover plate (16).

10. The battery according to claim 9, characterized in that, The housing (15) includes a cover plate mating part (151) that surrounds and forms the opening and a cell mating part (152) that surrounds and forms the receiving space. The wall thickness of the housing (15) in the cover plate mating part (151) is greater than the wall thickness in the cell mating part (152).

11. The battery according to claim 8, characterized in that, The pole (2) is disposed on the housing (15).

12. A battery pack, characterized in that, include: The battery according to any one of claims 7 to 11, wherein the battery is provided in a plurality of units; The busbar (6) is welded to the side of at least two of the battery terminals (2) away from the housing space.

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