Battery pole group and battery

Abstract

The application belongs to the technical field of batteries, and discloses a battery pole group and a battery. The battery pole group comprises a pole group main body and a pole lug. The pole group main body comprises an expansion pole body and a butt joint pole body. The cross-sectional area of the butt joint pole body perpendicular to a first direction is smaller than the cross-sectional area of the expansion pole body perpendicular to the first direction. The butt joint pole body is connected to both sides of the expansion pole body along the first direction, and an electrically conductive coating is coated between the end face where the butt joint pole body contacts the expansion pole body. Two protective bosses are arranged on the side of the butt joint pole body away from the expansion pole body along a second direction, and a containing groove is formed between the two protective bosses. An installation boss is arranged in the containing groove. The pole lug is connected to the installation boss and located in the containing groove. The volume of the battery pole group is increased by increasing the volume of the expansion pole body and adding the protective bosses and the installation boss, thereby improving the capacity. Moreover, the pole lug is arranged in the containing groove between the protective bosses, thereby avoiding damage to the pole lug when the battery pole group is inserted into a shell.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery electrode assembly and a battery. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage systems, and other fields, the market is placing increasingly higher demands on the energy density, safety, charge-discharge performance, and lifespan of power batteries. As a core component of power batteries, the structural design of the battery electrode assembly directly affects the overall performance of the battery. Within the limited space of the battery casing, how to improve energy density, enhance current conduction efficiency, and strengthen the structural stability of the electrode assembly during assembly by optimizing its structure has become one of the key research directions in the industry.

[0003] Traditional battery electrode assemblies typically employ a regular stacked or wound structure, forming a regular cuboid or cylinder. The multi-layered conductive tabs are integrated into a single unit, positioned on the same plane, and are generally directly connected to the terminal posts or connecting tabs on the battery cover using methods such as laser welding. During assembly, the thrust is often applied directly to the end face where the conductive tabs are located or the edge of the electrode assembly, relying on the structural strength of the electrode assembly itself to withstand the pressure during assembly.

[0004] However, traditional battery electrode packs have many limitations: First, due to the lack of a dedicated support structure, the thrust when the electrode pack is inserted into the casing acts directly on the conductive electrode tabs or the area near the conductive electrode tabs. The conductive electrode tabs are easily deformed or broken due to compression, or the welding joint between the conductive electrode tabs and the cover plate may result in poor welding or desoldering, affecting the battery's conductivity and sealing performance. Second, in order to avoid structural interference, traditional electrode packs often need to compress their own volume, making it difficult to make full use of the space inside the battery casing, thus limiting further increases in battery capacity. Summary of the Invention

[0005] The purpose of this invention is to provide a battery electrode assembly and battery that have good protection, large size, and high capacity.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On one hand, a battery electrode assembly is provided, the battery electrode assembly comprising:

[0008] The electrode assembly body includes an expansion electrode and a docking electrode. The cross-sectional area of ​​the docking electrode perpendicular to the first direction is smaller than the cross-sectional area of ​​the expansion electrode perpendicular to the first direction. The docking electrode is connected to both sides of the expansion electrode along the first direction, and a conductive coating is applied between the end faces of the docking electrode and the expansion electrode that are in contact. The docking electrode has two protective protrusions spaced apart along the second direction on the side away from the expansion electrode, and a receiving groove is formed between the two protective protrusions. A mounting protrusion is provided in the receiving groove.

[0009] The electrode tab is connected to the mounting boss and located within the receiving groove.

[0010] Optionally, the protective boss on the side away from the expansion electrode includes a first protective surface and a second protective surface. The second protective surface is inclined and connected to both sides of the first protective surface along a third direction. The distance between the two second protective surfaces gradually increases in the direction away from the first protective surface. The mounting boss on the side away from the expansion electrode includes an abutment surface and a mounting surface. The abutment surface is parallel to the first protective surface, and the mounting surface is parallel to the second protective surface and connected to both sides of the abutment surface along a third direction. Each mounting surface is connected to the electrode tab.

[0011] Optionally, the distance between the first protective surface and the abutting surface along the first direction is H1, and the distance between the abutting surface and the bottom surface of the accommodating groove along the first direction is H2, and satisfies 12mm≤H2-H1≤25mm.

[0012] Optionally, the length dimension of the first protective surface along the third direction is L1, and the thickness dimension of the docking electrode along the third direction is B1, and satisfies 0.33≤L1 / B1≤0.7.

[0013] Optionally, the thickness dimension of the expansion electrode along the third direction is B2, and the difference between the thickness dimension B2 of the expansion electrode along the third direction and the thickness dimension B1 of the docking electrode along the third direction satisfies 16mm≤B2-B1≤60mm.

[0014] Optionally, the distance between the two protective protrusions along the second direction is L2, and the width of the mating electrode along the second direction is A1, satisfying 0.4≤L2 / A1≤0.65.

[0015] Optionally, the width dimension of the expansion electrode along the second direction is A2, and the difference between the width dimension A2 of the expansion electrode along the second direction and the width dimension A1 of the docking electrode along the second direction satisfies 20mm≤A2-A1≤80mm.

[0016] Optionally, the expansion electrode includes a first end and a second end along the second direction. The end face of the expansion electrode connected to the docking electrode is provided with a docking boss extending from the first end to the second end. The docking boss is provided with an insertion groove. The end face of the docking electrode facing the expansion electrode is provided with an insertion boss. The insertion boss is inserted into the insertion groove. The projection range of the docking electrode on the expansion electrode along the first direction does not exceed the docking boss.

[0017] Optionally, the length of the first end along the first direction is W, and the length of the pole group body along the first direction is E, satisfying 0.3≤W / E≤0.5.

[0018] On the other hand, a battery is provided, the battery including a battery cover, a battery housing and a battery electrode assembly as described in any of the above claims, the battery housing being a hollow housing structure with an opening, the battery cover being disposed at the opening of the battery housing to close the battery housing and to form a closed cavity for accommodating the battery electrode assembly.

[0019] The beneficial effects of this invention are:

[0020] This invention provides a battery electrode assembly, comprising an expansion electrode and a docking electrode. By making the cross-sectional area of ​​the expansion electrode larger than that of the docking electrode, the volume of the expansion electrode is increased. Protective protrusions and mounting protrusions are provided on the docking electrode, thereby increasing the overall volume of the battery electrode assembly and improving its capacity. Furthermore, since the tabs connected to the mounting protrusions are located in the receiving groove between the two protective protrusions, the thrust can be applied to the protective protrusions when the battery electrode assembly is installed in the casing, avoiding direct force on the tabs and providing good protection for the tabs, reducing the occurrence of problems such as tab deformation and breakage.

[0021] The present invention also provides a battery that, by applying the above-described battery electrode assembly, not only reduces the risk of safety problems caused by overheating, but also increases the battery capacity, meets the demand for improved battery energy density, and thus has a longer driving range or a longer power supply time. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the battery electrode assembly provided by the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the docking electrode in the battery electrode assembly provided by the present invention from a first-view perspective;

[0024] Figure 3This is a schematic diagram of the structure of the docking electrode in the battery electrode assembly provided by the present invention from a second perspective.

[0025] Figure 4 This is a cross-sectional view of the structure of the docking electrode in the battery electrode assembly provided by the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the expansion electrode in the battery electrode assembly provided by the present invention;

[0027] Figure 6 This is a cross-sectional view of the battery electrode assembly provided by the present invention;

[0028] Figure 7 This is a top view of the battery electrode assembly provided by the present invention.

[0029] In the picture:

[0030] 1. Electrode assembly body; 11. Expanding electrode body; 111. First end; 112. Second end; 113. Docking boss; 114. Insertion groove; 115. Flow guide groove; 12. Docking electrode body; 121. Protective boss; 1211. First protective surface; 1212. Second protective surface; 122. Mounting boss; 1221. Abutment surface; 1222. Mounting surface; 123. Insertion boss; 124. Accommodating groove;

[0031] 2. Polar ears;

[0032] 3. Positive conductive coating;

[0033] 4. Negative electrode conductive coating. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0038] Traditional battery electrode packs have several limitations: First, due to the lack of a dedicated support structure, the thrust applied when the electrode pack is inserted into the casing is directly applied to the tabs or the area near the tabs. The tabs are easily deformed or broken due to compression, or the welding between the tabs and the cover plate may result in poor welding or detachment, affecting the battery's conductivity and sealing performance. Second, to avoid structural interference, traditional electrode packs often need to compress their own volume, making it difficult to fully utilize the space inside the battery casing and limiting further increases in battery capacity.

[0039] Therefore, in order to improve the protection of the tabs, increase the volume of the electrode assembly, and improve the capacity, this embodiment provides a battery electrode assembly. For ease of description, the length direction of the battery electrode assembly is defined as the first direction, the width direction as the second direction, and the height direction as the third direction.

[0040] like Figures 1 to 7 As shown, the battery electrode assembly includes an electrode assembly body 1 and electrode tabs 2. The electrode assembly body 1 includes an expansion electrode 11 and a docking electrode 12. The cross-sectional area of ​​the docking electrode 12 perpendicular to the first direction is smaller than the cross-sectional area of ​​the expansion electrode 11 perpendicular to the first direction. The docking electrode 12 is connected to both sides of the expansion electrode 11 along the first direction, and a conductive coating is applied between the end faces of the docking electrode 12 and the expansion electrode 11 that are in contact. On the side of the docking electrode 12 away from the expansion electrode 11, there are two protective protrusions 121 spaced apart along the second direction, and a receiving groove 124 is formed between the two protective protrusions 121. A mounting protrusion 122 is provided in the receiving groove 124. The electrode tabs 2 are connected to the mounting protrusions 122 and located in the receiving groove 124.

[0041] The main body 1 of the battery assembly is composed of an expansion electrode 11 and a docking electrode 12. By making the cross-sectional area of ​​the expansion electrode 11 larger than that of the docking electrode 12, the volume of the expansion electrode 11 is increased. A protective boss 121 and a mounting boss 122 are provided on the docking electrode 12, thereby increasing the overall volume of the battery assembly and improving the capacity. Furthermore, since the tabs 2 connected to the mounting boss 122 are located in the receiving groove 124 between the two protective bosses 121, the thrust can be applied to the protective bosses 121 when the battery assembly is inserted into the casing, avoiding direct force on the tabs 2 and providing good protection for the tabs 2, reducing the occurrence of problems such as deformation and breakage of the tabs 2.

[0042] In this embodiment, the expansion electrode 11 and the docking electrode 12 constituting the electrode assembly body 1 adopt a split structure design. This not only allows the expansion electrode 11 and the docking electrode 12 to have different structural forms to increase the volume of the electrode assembly body 1, but also facilitates the subsequent assembly of the battery electrode assembly with the battery casing using a split assembly method. However, since the expansion electrode 11 and the docking electrode 12 of the electrode assembly body 1 adopt a split structure design, it is necessary to coat the contact surfaces of the two to achieve current conduction between them. The conductive coating is a functional thin film prepared on the surface of substrates such as metal, plastic, glass, and ceramic through a specific process. The core is to achieve current conduction by means of electronic or ionic conduction mechanisms. In terms of type, it mainly includes metal-based coatings with the best conductivity but higher cost, carbon-based coatings with good chemical stability and lightweight, conductive polymer coatings with outstanding flexibility and transparency but weak conductivity, and composite coatings with customizable performance. In this embodiment, each end face with a conductive coating is provided with a positive electrode conductive coating 3 and a negative electrode conductive coating 4. In addition, in order to accelerate the flow rate of the medium inside the battery, such as electrolyte or gas, the electrode assembly body 1 is also provided with a flow channel 115 on the expanded electrode body 11.

[0043] Optionally, such as Figure 1 , Figure 2 As shown, the protective boss 121 on the side away from the expansion electrode 11 includes a first protective surface 1211 and a second protective surface 1212. The second protective surface 1212 is inclined and connected to both sides of the first protective surface 1211 along a third direction. The distance between the two second protective surfaces 1212 gradually increases in the direction away from the first protective surface 1211. The mounting boss 122 on the side away from the expansion electrode 11 includes an abutment surface 1221 and a mounting surface 1222. The abutment surface 1221 is parallel to the first protective surface 1211, and the mounting surface 1222 is parallel to the second protective surface 1212 and connected to both sides of the abutment surface 1221 along a third direction. Each mounting surface 1222 is connected to an electrode tab 2.

[0044] By providing inclined second protective surfaces 1212 on both sides of the first protective surface 1211, not only can the contact area between the protective boss 121 and the battery cover be increased, ensuring the stability of the support, but also, when external loads are applied to the protective boss 121, the inclined second protective surfaces 1212 can decompose the vertical or horizontal loads into components along the second protective surfaces 1212, and then transfer them to the root of the protective boss 121. This avoids the load being concentrated at a single support point, improves the stress condition of the protective boss 121, and gives the protective boss 121 a higher load capacity. Furthermore, by providing tabs 2 on the mounting surfaces 1222 on both sides of the contact surface 1221, a multi-tab structure is formed, which effectively increases the current-carrying area of ​​the tabs 2, improves the current-carrying capacity, and reduces the temperature of the tabs 2 during the current-carrying process, thereby improving the charging and discharging performance and safety of the battery.

[0045] Optionally, such as Figure 2 , Figure 4 As shown, the distance between the first protective surface 1211 and the abutting surface 1221 along the first direction is H1, and the distance between the abutting surface 1221 and the bottom surface of the accommodating groove 124 along the first direction is H2, and satisfies 12mm≤H2-H1≤25mm. By limiting the difference between the spacing H2 between the bottom surface of the contact surface 1221 and the receiving groove 124 along the first direction and the spacing H1 between the first protective surface 1211 and the contact surface 1221 along the first direction, such that 12mm≤H2-H1≤25mm is satisfied, it is possible to avoid the difference being too small, which would cause the mounting boss 122 to be too high, making the tab 2 connected to the mounting boss 122 too close to the edge of the receiving groove 124, making the tab 2 easily damaged by the movement of the battery electrode assembly. On the other hand, it is also possible to avoid the difference being too large, which would cause the mounting boss 122 to be too small, which would not only result in insufficient area for mounting the tab 2, compressing the size of the tab 2, reducing the current carrying capacity of the tab 2, but also reduce the volume of the mounting boss 122, thus reducing the capacity of the electrode assembly body 1.

[0046] The difference between the distance H2 between the abutting surface 1221 and the bottom surface of the receiving groove 124 along the first direction and the distance H1 between the first protective surface 1211 and the abutting surface 1221 along the first direction can be any value between 12mm and 25mm or any two values, such as 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, etc.

[0047] Optionally, such as Figure 2 , Figure 4As shown, the length dimension of the first protective surface 1211 along the third direction is L1, and the thickness dimension of the docking electrode 12 along the third direction is B1, and the condition 0.33≤L1 / B1≤0.7 is satisfied. By limiting the ratio between the length L1 of the first protective surface 1211 along the third direction and the thickness B1 of the docking electrode 12 along the third direction, such that 0.33≤L1 / B1≤0.7, we can prevent the ratio from being too small, which would result in an insufficient contact area between the first protective surface 1211 and the battery cover, leading to poor support stability. On the other hand, by tilting the second protective surface 1212, we can help distribute the load acting on the protective boss 121 and improve the load-bearing capacity of the protective boss 121. Therefore, by avoiding an excessively large ratio, which would cause the angle between the second protective surface 1212 and the first protective surface 1211 to approach perpendicularity due to the excessive size of the first protective surface 1211, we can reduce the ability of the second protective surface 1212 to distribute the load and decrease the load-bearing capacity of the protective boss 121.

[0048] The ratio between the length L1 of the first protective surface 1211 along the third direction and the thickness B1 of the docking electrode 12 along the third direction can be any value between 0.33 and 0.7 or any range between two values, such as 0.33, 0.404, 0.478, 0.552, 0.626, 0.7, etc.

[0049] Optionally, such as Figure 4 , Figure 7 As shown, the thickness dimension of the expansion electrode 11 along the third direction is B2. The difference between the thickness dimension B2 of the expansion electrode 11 along the third direction and the thickness dimension B1 of the docking electrode 12 along the third direction satisfies 16mm≤B2-B1≤60mm. By limiting the difference between the thickness B2 of the expansion electrode 11 along the third direction and the thickness B1 of the docking electrode 12 along the third direction, ensuring that it satisfies 16mm≤B2-B1≤60mm, the following measures are taken: First, the difference is avoided from being too small, which would result in the expansion electrode 11 being too thin while maintaining a certain thickness of the docking electrode 12, thus making the volume of the expansion electrode 11 insufficient to meet the capacity expansion requirements of the battery pack. Second, the difference is avoided from being too large, which would result in the docking electrode 12 being too thin while meeting the capacity expansion requirements, thus making the area of ​​the docking electrode 12 for setting the protective boss 121 and the mounting boss 122 too small, compressing the thickness of the protective boss 121 and the mounting boss 122, resulting in poor structural strength of the protective boss 121 and the mounting boss 122, making them prone to breakage.

[0050] The difference between the thickness dimension B2 of the expansion electrode 11 along the third direction and the thickness dimension B1 of the docking electrode 12 along the third direction can be any value between 16mm and 60mm or any range between two values, such as 16mm, 27mm, 38mm, 49mm, 60mm, etc.

[0051] In this embodiment, to verify the impact of the above parameter limitations on the battery electrode assembly provided in this embodiment, as shown in Table 1, six sets of embodiments and six sets of comparative examples are provided for verification.

[0052] Table 1

[0053]

[0054] A comparison of Examples 1 to 6 with Comparative Examples 1 to 2 reveals that when the difference between the distance H2 between the abutting surface 1221 and the bottom surface of the receiving groove 124 along the first direction and the distance H1 between the first protective surface 1211 and the abutting surface 1221 along the first direction is less than the minimum value within the range of 12mm ≤ H2 - H1 ≤ 25mm, the difference is too small. This results in the mounting boss 122 being too high, causing the tab 2 connected to the mounting boss 122 to be too close to the edge of the receiving groove 124. Consequently, the tab 2 is prone to damage due to the movement of the battery electrode assembly. Damage occurs when the difference between the spacing H2 between the contact surface 1221 and the bottom surface of the receiving groove 124 along the first direction and the spacing H1 between the first protective surface 1211 and the contact surface 1221 along the first direction is greater than the maximum value of the range 12mm≤H2-H1≤25mm. This excessive difference results in the mounting boss 122 being too small. This not only leads to insufficient area for the mounting boss 122 to set the electrode tab 2, compressing the size of the electrode tab 2 and reducing its current carrying capacity, but also reduces the volume of the mounting boss 122, thereby reducing the capacity of the electrode assembly body 1.

[0055] A comparison of Examples 1 to 6 with Comparative Examples 3 to 4 reveals that when the ratio between the length L1 of the first protective surface 1211 along the third direction and the thickness B1 of the docking electrode 12 along the third direction is less than the minimum value in the range 0.33≤L1 / B1≤0.7, the ratio is too small, resulting in an insufficient contact area between the first protective surface 1211 and the battery cover, leading to poor support stability. Conversely, when the ratio between the length L1 of the first protective surface 1211 along the third direction and the thickness B1 of the docking electrode 12 along the third direction is greater than the maximum value in the range 0.33≤L1 / B1≤0.7, the ratio is too large, causing the angle between the second protective surface 1212 and the first protective surface 1211 to approach perpendicularity due to the excessive size of the first protective surface 1211. This weakens the ability of the second protective surface 1212 to distribute loads and reduces the load-bearing capacity of the protective boss 121.

[0056] A comparison of Examples 1 to 6 with Comparative Examples 5 to 6 reveals that when the difference between the thickness B2 of the expanded electrode 11 along the third direction and the thickness B1 of the docking electrode 12 along the third direction is less than the minimum value within the range of 16mm ≤ B2 - B1 ≤ 60mm, the difference is too small. This results in the expanded electrode 11 being too thin while maintaining a constant thickness of the docking electrode 12. Consequently, the volume of the expanded electrode 11 does not meet the capacity expansion requirements of the battery electrode assembly. When the difference between the thickness dimensions B1 of the docking electrode 12 along the third direction is greater than the maximum value of the range 16mm≤B2-B1≤60mm, the difference is too large. This results in insufficient thickness of the docking electrode 12, even if the volume of the expansion electrode 11 meets the expansion requirements. Consequently, the area of ​​the docking electrode 12 used to set the protective boss 121 and the mounting boss 122 is too small, compressing the thickness dimensions of the protective boss 121 and the mounting boss 122. This leads to poor structural strength of the protective boss 121 and the mounting boss 122, making them prone to breakage.

[0057] Optionally, such as Figure 2 , Figure 6As shown, the distance between the two protective bosses 121 along the second direction is L2, and the width of the mating electrode 12 along the second direction is A1, satisfying 0.4≤L2 / A1≤0.65. By limiting the ratio between the distance L2 between the two protective bosses 121 along the second direction and the width A1 of the mating electrode 12 along the second direction to satisfy 0.4≤L2 / A1≤0.65, we can avoid two problems: firstly, the ratio being too small, which would result in a small distance between the two protective bosses 121, compressing the size of the mounting boss 122 between the protective bosses 121, and making the area for mounting the tab 2 insufficient, leading to a smaller tab 2 size and reduced current carrying capacity; secondly, the ratio being too large, which would result in a large distance between the two protective bosses 121, reducing the size of the protective bosses 121 and thus reducing the structural strength of the protective bosses 121.

[0058] The ratio between the spacing L2 of the two protective protrusions 121 along the second direction and the width A1 of the mating electrode 12 along the second direction can be any value between 0.4 and 0.65 or any range between two values, such as 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, etc.

[0059] Optionally, such as Figure 6 As shown, the width dimension of the expansion electrode 11 along the second direction is A2. The difference between the width dimension A2 of the expansion electrode 11 along the second direction and the width dimension A1 of the docking electrode 12 along the second direction satisfies 20mm≤A2-A1≤80mm. By limiting the difference between the width dimension A2 of the expansion electrode 11 along the second direction and the width dimension A1 of the docking electrode 12 along the second direction, such that it satisfies 20mm≤A2-A1≤80mm, the following measures are taken: Firstly, the difference is avoided from being too small, which would result in the expansion electrode 11 being too small while maintaining a certain width of the docking electrode 12, thus making the volume of the expansion electrode 11 insufficient to meet the expansion requirements of the battery electrode assembly. Secondly, the difference is avoided from being too large, which would result in the width of the docking electrode 12 being insufficient while meeting the expansion requirements, thus making the area of ​​the docking electrode 12 for setting the protective boss 121 and the mounting boss 122 too small, compressing the width dimension of the protective boss 121 and the mounting boss 122, resulting in poor structural strength of the protective boss 121 and the mounting boss 122, making them prone to breakage.

[0060] The difference between the width dimension A2 of the expansion electrode 11 along the second direction and the width dimension A1 of the docking electrode 12 along the second direction can be any value between 20mm and 80mm or any two values, such as 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, etc.

[0061] Optionally, such as Figure 1 , Figure 5 As shown, the expansion electrode 11 includes a first end 111 and a second end 112 along the second direction. The end face of the expansion electrode 11 connected to the docking electrode 12 is provided with a docking boss 113 extending from the first end 111 to the second end 112. The docking boss 113 is provided with an insertion groove 114. The end face of the docking electrode 12 facing the expansion electrode 11 is provided with an insertion boss 123. The insertion boss 123 is inserted into the insertion groove 114. The projection range of the docking electrode 12 along the first direction on the expansion electrode 11 does not exceed the docking boss 113.

[0062] By separately providing a mating boss 113 on the expansion electrode 11 for connection with the mating electrode 12, the original size of the expansion electrode 11 will not be reduced after the insertion groove 114 is opened. Furthermore, since the mating boss 113 extends from the first end 111 to the second end 112 of the expansion electrode 11, the mating boss 113 does not completely cover the end face of the expansion electrode 11 facing the mating electrode 12. Therefore, by ensuring that the projection range of the mating electrode 12 on the expansion electrode 11 along the first direction does not exceed the mating boss 113, the suspended part between the mating electrode 12 and the expansion electrode 11 is avoided, thus ensuring that there is sufficient contact area between the mating electrode 12 and the expansion electrode 11.

[0063] In this embodiment, the height of the mating boss 113 is consistent with the depth of the insertion groove 114, thereby ensuring that the insertion groove 114 has sufficient depth for insertion with the insertion boss 123 without reducing the original volume of the expansion electrode 11.

[0064] Optionally, such as Figure 5 , Figure 6 As shown, the length of the first end 111 along the first direction is W, and the length of the electrode body 1 along the first direction is E, satisfying 0.3≤W / E≤0.5. By limiting the ratio between the length W of the first end 111 along the first direction and the length E of the electrode body 1 along the first direction, ensuring that it satisfies 0.3≤W / E≤0.5, this avoids two problems: firstly, the ratio being too small, resulting in an insufficient volume of the expanded electrode 11 due to the length W of the first end 111 along the first direction being too small, thus failing to meet the capacity expansion requirements of the battery electrode assembly; secondly, the ratio being too large, resulting in an excessive length difference between the first end 111 and the second end 112 of the expanded electrode 11, leading to excessive center of gravity shift of the expanded electrode 11 and affecting the overall stability after battery assembly.

[0065] The ratio between the length W of the first end 111 along the first direction and the length E of the pole body 1 along the first direction can be any value between 0.3 and 0.5 or any range between two values, such as 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0066] In this embodiment, to verify the impact of the above parameter limitations on the battery electrode assembly provided in this embodiment, as shown in Table 2, six sets of embodiments and six sets of comparative examples are provided for verification.

[0067] Table 2

[0068]

[0069] A comparison of Examples 7 to 12 with Comparative Examples 7 to 8 reveals that when the ratio between the spacing L2 of the two protective protrusions 121 along the second direction and the width A1 of the mating electrode 12 along the second direction is less than the minimum value in the range 0.4 ≤ L2 / A1 ≤ 0.65, the ratio is too small, resulting in an excessively small spacing between the two protective protrusions 121. This compresses the size of the mounting protrusion 122 between the protective protrusions 121, leading to insufficient area for the mounting protrusion 122 to accommodate the electrode tab 2. Consequently, the size of the electrode tab 2 decreases, reducing its current carrying capacity. Conversely, when the ratio between the spacing L2 of the two protective protrusions 121 along the second direction and the width A1 of the mating electrode 12 along the second direction is greater than the maximum value in the range 0.4 ≤ L2 / A1 ≤ 0.65, the ratio is too large, resulting in an excessively large spacing between the two protective protrusions 121. This causes the size of the protective protrusions 121 to shrink, thereby reducing the structural strength of the protective protrusions 121.

[0070] A comparison of Examples 7 to 12 with Comparative Examples 9 to 10 reveals that when the difference between the width dimension A2 of the expanded electrode 11 along the second direction and the width dimension A1 of the docking electrode 12 along the second direction is less than the minimum value of the range 20mm≤A2-A1≤80mm, the difference is too small, and the width of the expanded electrode 11 is too small, resulting in the volume of the expanded electrode 11 not meeting the capacity expansion requirements of the battery electrode pack. When the difference between the width dimension A2 of the expanded electrode 11 along the second direction and the width dimension A1 of the docking electrode 12 along the second direction is greater than the maximum value of the range 20mm≤A2-A1≤80mm, the difference is too large, and the width of the docking electrode 12 is insufficient, resulting in the area of ​​the docking electrode 12 for setting the protective boss 121 and the mounting boss 122 being too small, compressing the width dimension of the protective boss 121 and the mounting boss 122, and causing poor structural strength of the protective boss 121 and the mounting boss 122.

[0071] A comparison of Examples 7 to 12 with Comparative Examples 11 to 12 shows that when the ratio of the length W of the first end 111 along the first direction to the length E of the electrode body 1 along the first direction is less than the minimum value in the range 0.3≤W / E≤0.5, the ratio is too small, resulting in insufficient volume of the expanded electrode 11, which does not meet the expansion requirements of the battery electrode group. When the ratio of the length W of the first end 111 along the first direction to the length E of the electrode body 1 along the first direction is greater than the maximum value in the range 0.3≤W / E≤0.5, the ratio is too large, resulting in excessive length difference between the first end 111 and the second end 112 of the expanded electrode 11, causing excessive shift of the center of gravity of the expanded electrode 11, which affects the overall stability after battery assembly.

[0072] In this embodiment, a battery is also provided, which includes a battery cover, a battery housing, and the aforementioned battery electrode assembly. The battery housing is a hollow housing structure with at least one opening. The battery cover is disposed at the opening of the battery housing and closes the battery housing to form a closed cavity for accommodating the battery electrode assembly.

[0073] By applying the aforementioned battery electrode assembly, this battery not only reduces the risk of safety issues caused by overheating, but also increases the battery capacity, meeting the demand for improved battery energy density, thereby achieving longer battery life or longer power supply time.

[0074] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery electrode assembly, characterized in that, The battery electrode assembly includes: The electrode assembly body includes an expansion electrode and a docking electrode. The cross-sectional area of ​​the docking electrode perpendicular to the first direction is smaller than the cross-sectional area of ​​the expansion electrode perpendicular to the first direction. The docking electrode is connected to both sides of the expansion electrode along the first direction, and a conductive coating is applied between the end faces of the docking electrode and the expansion electrode that are in contact. The docking electrode has two protective protrusions spaced apart along the second direction on the side away from the expansion electrode, and a receiving groove is formed between the two protective protrusions. A mounting protrusion is provided in the receiving groove. The electrode tab is connected to the mounting boss and located within the receiving groove.

2. The battery electrode assembly according to claim 1, characterized in that, The protective boss on the side away from the expansion electrode includes a first protective surface and a second protective surface. The second protective surface is inclined and connected to both sides of the first protective surface along a third direction. The distance between the two second protective surfaces gradually increases in the direction away from the first protective surface. The mounting boss on the side away from the expansion electrode includes an abutment surface and a mounting surface. The abutment surface is parallel to the first protective surface, and the mounting surface is parallel to the second protective surface and connected to both sides of the abutment surface along a third direction. Each mounting surface is connected to the electrode tab.

3. The battery electrode assembly according to claim 2, characterized in that, The distance between the first protective surface and the abutting surface along the first direction is H1, and the distance between the abutting surface and the bottom surface of the accommodating groove along the first direction is H2, and satisfies 12mm≤H2-H1≤25mm.

4. The battery electrode assembly according to claim 2, characterized in that, The length dimension of the first protective surface along the third direction is L1, and the thickness dimension of the docking electrode along the third direction is B1, and the condition 0.33≤L1 / B1≤0.7 is satisfied.

5. The battery electrode assembly according to claim 4, characterized in that, The thickness dimension of the expansion electrode along the third direction is B2, and the difference between the thickness dimension B2 of the expansion electrode along the third direction and the thickness dimension B1 of the docking electrode along the third direction satisfies 16mm≤B2-B1≤60mm.

6. The battery electrode assembly according to claim 1, characterized in that, The distance between the two protective protrusions along the second direction is L2, and the width of the mating electrode along the second direction is A1, satisfying 0.4≤L2 / A1≤0.

65.

7. The battery electrode assembly according to claim 6, characterized in that, The width dimension of the expansion electrode along the second direction is A2, and the difference between the width dimension A2 of the expansion electrode along the second direction and the width dimension A1 of the docking electrode along the second direction satisfies 20mm≤A2-A1≤80mm.

8. The battery electrode assembly according to claim 1, characterized in that, The expansion electrode includes a first end and a second end along the second direction. The end face of the expansion electrode connected to the docking electrode is provided with a docking boss extending from the first end to the second end. The docking boss is provided with an insertion groove. The end face of the docking electrode facing the expansion electrode is provided with an insertion boss. The insertion boss is inserted into the insertion groove. The projection range of the docking electrode on the expansion electrode along the first direction does not exceed the docking boss.

9. The battery electrode assembly according to claim 8, characterized in that, The length of the first end along the first direction is W, and the length of the pole group body along the first direction is E, satisfying 0.3≤W / E≤0.

5.

10. A battery, characterized in that, The battery includes a battery cover, a battery housing, and a battery electrode assembly as described in any one of claims 1-9. The battery housing is a hollow housing structure with an opening. The battery cover is disposed at the opening of the battery housing to close the battery housing and form a closed cavity for accommodating the battery electrode assembly.

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