Battery and battery pack

Abstract

The battery comprises a shell, a battery cell assembly and a battery cover plate, the shell is provided with a containing cavity and an opening communicated with the containing cavity, the battery cell assembly is arranged in the containing cavity, the battery cover plate comprises a cover body, a first pole column and a second pole column, the cover body covers the opening, and the first pole column and the second pole column are arranged in the containing cavity. The first pole and the second pole are respectively and electrically connected with the battery core assembly, the cover body is provided with a mounting hole, the first pole and the second pole are arranged in the mounting hole in a penetrating manner, the conductivity of the material of the first pole is lower than that of the material of the second pole, the length directions of the first pole and the second pole are parallel to each other and are perpendicular to a reference plane C1, and the length direction of the second pole is perpendicular to the reference plane C1. The first pole and the second pole are equal in length, and the projection area of the first pole on the reference plane C1 is larger than that of the second pole; or the projection area of the first pole on the reference plane C1 is equal to that of the second pole, and the length of the first pole is smaller than that of the second pole, so that the technical problem that the temperatures of the positive pole and the negative pole in a related battery structure are not uniform is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery and a battery pack. Background Art

[0002] With the rapid development of the new energy industry, batteries are widely used in electric vehicles, energy storage equipment and portable electronic devices as the main energy storage device. Lithium-ion batteries have become the mainstream of the market due to their high energy density, long cycle life and excellent stability.

[0003] The positive and negative poles in the battery are important parts that connect the internal and external circuits of the battery. They are connected to the electrode material through the current collector to conduct or import the current generated in the electrochemical reaction into the external circuit. Usually, aluminum is used for the positive pole and copper is used for the negative pole. During the charging and discharging process of the battery, due to the difference in the conductivity of the two materials, the resistance of the positive and negative poles when current passes through is different. Due to the higher resistivity of aluminum, the positive pole is more likely to generate higher resistance heat than the copper negative pole with better conductivity, resulting in a temperature difference between the positive and negative poles. The temperature difference will have a negative impact on the ion transmission efficiency inside the battery, thereby accelerating the attenuation of battery performance and even shortening the battery life.

[0004] Therefore, the problem of uneven temperature of the positive and negative poles in the relevant battery structure needs to be solved urgently. Summary of the invention

[0005] An object of the present invention is to provide a battery and a battery pack, which are intended to solve the technical problem of uneven temperature of positive and negative poles in related battery structures.

[0006] To achieve the above-mentioned purpose, the present invention provides a solution: a battery, the battery comprising a shell, a receiving cavity and an opening connected to the receiving cavity; a battery cell assembly, arranged in the receiving cavity; a battery cover, comprising a cover body, a first pole and a second pole, the cover body sealing the opening, the first pole and the second pole are electrically connected to the battery cell assembly respectively, the cover body is provided with a mounting hole, the first pole and the second pole are passed through the mounting hole, the conductivity of the material of the first pole is lower than the conductivity of the material of the second pole; wherein the length direction of the first pole and the length direction of the second pole are parallel to each other, The length of the first pole is equal to the length of the second pole, the projection area of ​​the first pole on the reference plane C1 is greater than the projection area of ​​the second pole on the reference plane C1, and the reference plane C1 is perpendicular to the length direction of the first pole and the length direction of the second pole; or the length direction of the first pole and the length direction of the second pole are parallel to each other, and the projection area of ​​the first pole on the reference plane C1 is equal to the projection area of ​​the second pole on the reference plane C1, the length of the first pole is less than the length of the second pole, and the reference plane C1 is perpendicular to the length direction of the first pole and the length direction of the second pole.

[0007] Optionally, a ratio of a projection area of ​​the first pole on the reference plane C1 to a projection area of ​​the second pole on the reference plane C1 is m, and 1.11≤m≤1.14.

[0008] Optionally, the first pole or the second pole includes a pole portion and a connecting portion, the pole portion and the connecting portion are integrally formed, and the connecting portion is used to connect the pole portion and the battery cell assembly.

[0009] Optionally, the connecting portion includes a clamping end and a connecting end that are connected to each other, the clamping end is used to clamp and connect the battery cell assembly, and the connecting end connects the clamping end and the pole portion.

[0010] Optionally, the battery cell assembly includes a positive electrode ear, a positive electrode collector, a negative electrode ear and a negative electrode collector, the positive electrode ear is respectively connected to the positive electrode collector and the first electrode column, and the negative electrode ear is respectively connected to the negative electrode collector and the second electrode column; wherein the thickness of the positive electrode ear is the same as the thickness of the negative electrode ear, the length of the positive electrode ear is the same as the length of the negative electrode ear, and the width of the positive electrode ear is greater than the width of the negative electrode ear.

[0011] Optionally, a ratio of the width of the positive electrode tab to the width of the negative electrode tab is n, and 1.11≤n≤1.14.

[0012] Optionally, the contact area between the positive electrode tab and the first electrode post is greater than the contact area between the negative electrode tab and the second electrode post.

[0013] Optionally, the thickness direction of the positive current collector is parallel to the thickness direction of the negative current collector, the projected area of ​​the positive current collector on the reference plane C2 is equal to the projected area of ​​the negative current collector on the reference plane C2, the thickness of the positive current collector is greater than the thickness of the negative current collector, and the reference plane C2 is perpendicular to the thickness direction of the positive current collector and the thickness direction of the negative current collector.

[0014] Optionally, the ratio of the thickness of the positive electrode current collector to the thickness of the negative electrode current collector is h, and 1.15≤h≤1.17.

[0015] In order to achieve the above object, the present invention further provides a solution: a battery pack, comprising the above battery.

[0016] The beneficial effects of the present invention are:

[0017] Different from the prior art, the present application increases the cross-sectional area of ​​the first pole to make it larger than the cross-sectional area of ​​the second pole while keeping the length of the first pole the same as that of the second pole; or shortens the length of the first pole to make it smaller than that of the second pole while keeping the cross-sectional areas of the first pole equal to those of the second pole. This makes up for the inherent defect that the conductivity of the material of the first pole is lower than that of the material of the second pole, so that the first pole has a current capacity close to that of the second pole. This optimization balances the current conduction capacity between the poles, thereby effectively alleviating the temperature difference between the poles, avoiding the uneven reaction rate of the positive and negative active materials due to the temperature difference, and the capacity decay or active material failure that may be caused. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 is an overall schematic diagram of a battery provided by an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the battery cover structure provided by an embodiment of the present invention;

[0021] Figure 3 is an overall schematic diagram of a battery cell assembly provided by an embodiment of the present invention;

[0022] Figure 4 is a top view of a battery provided by an embodiment of the present invention;

[0023] Figure 5 The embodiment of the present invention provides Figure 4 Sectional view in the AA direction;

[0024] Figure 6 It is a schematic diagram of the structure of a battery cell assembly provided in an embodiment of the present invention.

[0025] Description of Figure Numbers:

[0026] 10. Shell; 11. Accommodating cavity; 12. Opening; 20. Battery cell assembly; 21. Positive electrode ear; 22. Negative electrode ear; 23. Positive electrode collector; 24. Negative electrode collector; 30. Battery cover; 31. Cover; 311. Mounting hole; 32. First pole; 33. Second pole; 34. Pole part; 35. Connecting part; 351. Clamping end; 352. Connecting end. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figures 1 to 3 , Figure 1 is an overall schematic diagram of a battery provided by an embodiment of the present invention, Figure 2 is a schematic structural diagram of a battery cover plate 30 provided in an embodiment of the present invention, Figure 3 It is an overall schematic diagram of a battery cell assembly 20 provided in an embodiment of the present invention.

[0029] The embodiment of the present invention provides a battery, aiming to alleviate the problem of uneven temperature distribution caused by the difference in conductivity between positive and negative poles, thereby improving the safety and operation stability of the battery.

[0030] In the present application, the battery includes a shell 10, a battery cell assembly 20 and a battery cover 30. The shell 10, as the main structure of the battery, is provided with a housing chamber 11 and an opening 12 connected to the housing chamber 11, which is used to install the battery cell assembly 20 and provide protection. The battery cell assembly 20 is arranged in the housing chamber 11, which is the core part of the battery energy storage and realizes energy conversion through electrochemical reactions. The battery cover 30 is arranged at the opening 12 of the shell 10, which plays a role of closing and sealing, and also includes a cover 31, a first pole 32 and a second pole 33 to realize the connection between the battery and the external circuit.

[0031] In the specific design, the cover 31 is provided with a mounting hole 311 for accommodating the first pole 32 and the second pole 33. The first pole 32 and the second pole 33 can be provided in the same cover 31, or in different covers 31 respectively. In this embodiment, the same cover 31 is used for illustration. The material conductivity of the first pole 32 is lower than that of the second pole 33, and usually corresponds to the positive pole (aluminum) and the negative pole (copper). To ensure structural symmetry, the length directions of the first pole 32 and the second pole 33 are parallel to each other, and pass through the mounting hole 311 to be electrically connected to the battery cell assembly 20.

[0032] On this basis, in order to improve the current carrying capacity of the first pole 32, the present application improves its current conducting performance in two ways: one is to increase the current carrying capacity by increasing its cross-sectional area, and the other is to increase the current carrying capacity by shortening its length.

[0033] Specifically, in the first method, when the lengths of the first pole 32 and the second pole 33 are equal, on the reference plane C1 (a plane perpendicular to the length directions of the first pole 32 and the second pole 33), the projected area of ​​the first pole 32 is designed to be larger than the projected area of ​​the second pole 33, thereby significantly improving the conductivity of the first pole 32. Figure 2 The Z1 direction is the length direction of the first pole 32 and the second pole 33 , and the reference plane C1 is perpendicular to the Z1 direction.

[0034] The second method is that on the reference plane C1 (a plane perpendicular to the length direction of the first pole 32 and the second pole 33), when the projected area of ​​the first pole 32 is equal to the projected area of ​​the second pole 33, the length of the first pole 32 is designed to be smaller than the length of the second pole 33, thereby improving the conductivity of the first pole 32.

[0035] In this embodiment, first, the present application directly reduces the resistance of the first pole 32 by increasing the cross-sectional area or shortening the length of the first pole 32, thereby enhancing its current carrying capacity. When current passes through the first pole 32, due to its reduced resistance, the generated resistance heat is significantly reduced, thereby effectively reducing the temperature rise of the positive pole, and significantly alleviating the temperature difference between the positive and negative poles. Compared with the traditional design, the battery cover 30 alleviates the temperature difference problem caused by the difference in conductivity by optimizing the pole structure.

[0036] Furthermore, in order to achieve structural balance while optimizing the conductive performance of the positive and negative poles, the present application quantitatively sets the projected areas of the first pole 32 and the second pole 33 on the reference plane C1. Specifically, the ratio of the projected area of ​​the first pole 32 on the reference plane C1 to the projected area of ​​the second pole 33 on the reference plane C1 is set to m, and its range is limited to 1.11≤m≤1.14.

[0037] In this embodiment, the determination of the parameters is based on a comprehensive consideration of the difference in material conductivity and current distribution optimization. Since the conductivity of the material of the first pole 32 is relatively low and its resistance is higher than that of the material of the second pole 33, it is necessary to increase the cross-sectional area of ​​the first pole 32 to make up for its insufficient conductivity. However, the increase in cross-sectional area cannot be unlimited, and the size of the pole is limited by the overall space layout and packaging requirements.

[0038] Through research, it was found that when the projected area of ​​the first pole 32 is 1.11 to 1.14 times the projected area of ​​the second pole 33, the current carrying capacity of the first pole 32 can be effectively improved without significantly increasing the volume of the pole, while ensuring that the temperature difference between the first pole 32 and the second pole 33 is controlled within a reasonable range, achieving a balance between structural and performance optimization.

[0039] Specifically, when the ratio m is close to 1.11, although the cross-sectional area of ​​the first pole 32 is increased, the improvement in the current capacity is relatively limited, and may not be sufficient to completely compensate for the temperature rise caused by the conductivity difference in some high-rate charge and discharge scenarios; and when the ratio m is close to 1.14, the cross-sectional area of ​​the first pole 32 is significantly increased, the conductivity is further improved, and the heat dissipation performance is also enhanced, but it may occupy more structural space and have a certain impact on the overall layout of the battery. Therefore, controlling m within the range of 1.11 to 1.14 can not only balance the contradiction between the improvement of conductivity and space utilization, but also ensure the overall thermal management performance and operational reliability of the battery.

[0040] See also Figure 4 and Figure 5 , Figure 4 is a top view of a battery provided by an embodiment of the present invention, Figure 5 The embodiment of the present invention provides Figure 4 Cross-sectional view along the AA direction.

[0041] In some embodiments, in order to simplify the battery structure and improve the structural stability, the first pole 32 or the second pole 33 further includes a pole portion 34 and a connecting portion 35, and the pole portion 34 and the connecting portion 35 are manufactured by integral molding. Specifically, the pole portion 34 is a part of the battery external connecting portion 35, which is used to achieve electrical connection with an external circuit; the connecting portion 35 is located between the pole portion 34 and the battery cell assembly 20, and is responsible for reliably connecting the pole portion 34 and the battery cell assembly 20, thereby ensuring efficient conduction of current and the overall stability of the battery structure.

[0042] In the prior art, the pole and the battery cell are usually electrically connected via an independent connecting piece, which is generally connected to the pole and the battery cell assembly 20 by welding, riveting or other mechanical fixing methods.

[0043] In this embodiment, compared with the battery structure in the prior art, the present application eliminates the independent connecting piece by integrally forming the pole part 34 and the connecting part 35, thereby fundamentally simplifying the internal structure of the battery and reducing the assembly error between components. At the same time, since the one-piece molding avoids the contact point between the pole and the connecting piece, the current achieves a more continuous conductive path during the conduction process, thereby reducing the contact resistance and improving the conductive efficiency of the battery. In addition, the one-piece molded structure does not have an additional seam between the connecting part 35 and the pole part 34, and the overall strength is higher, which can better withstand external vibration and impact, and improve the reliability and durability of the battery.

[0044] Furthermore, the connecting portion 35 includes a clamping end 351 and a connecting end 352 that are connected to each other, wherein the clamping end 351 is used to clamp and electrically connect the battery cell assembly 20, and the connecting end 352 plays a bridging role to reliably connect the clamping end 351 and the pole portion 34 to form a continuous conductive path.

[0045] Specifically, the shape and size of the clamping end 351 can be optimized according to the specific form of the battery cell assembly 20 to achieve stable contact and good conductivity. The clamping end 351 can be a slot-type structure, so that the end of the battery cell assembly 20 can be firmly embedded in the clamping end 351, enhancing mechanical stability and reliability of electrical connection. In addition, in order to further improve the conductivity of the clamping end 351, its surface can also be electroplated to reduce the resistance when current passes through, while improving corrosion resistance and extending service life.

[0046] The connection end 352 serves as a bridge between the clamping end 351 and the pole part 34, and is usually a smooth transition structure to ensure the continuity of the current during the conduction process. The length and thickness of the connection end 352 can be adjusted according to the specific power requirements and spatial layout of the battery. A shorter connection end 352 can reduce the current transmission path, thereby reducing the overall resistance; appropriate thickening can improve the conductivity and mechanical strength. In addition, the material of the connection end 352 is consistent with the pole part 34 to ensure the consistency of the conductive performance and the matching of the thermal expansion characteristics, avoiding stress concentration or fatigue damage caused by material differences.

[0047] In this embodiment, the clamping end 351 clamps and connects the battery cell assembly 20, maintains a firm contact between the battery cell assembly 20 and the pole, and maintains stable conductivity even under high-rate charge and discharge conditions. The connecting end 352 allows the current to be transmitted more smoothly between the clamping end 351 and the pole portion 34, reducing energy loss and improving the overall efficiency of the battery. By introducing the division of labor and synergy of the clamping end 351 and the connecting end 352 in the connecting portion 35, a stable connection with the battery cell assembly 20 is ensured, and the current transmission path is optimized.

[0048] See also Figure 3 and Figure 6 , Figure 3 is an overall schematic diagram of a battery cell assembly 20 provided in an embodiment of the present invention, Figure 6 It is a schematic structural diagram of a battery cell assembly 20 provided in an embodiment of the present invention.

[0049] In some embodiments, the battery cell assembly 20 includes a positive electrode ear 21, a positive electrode current collector 23, a negative electrode ear 22, and a negative electrode current collector 24, which are respectively used to realize the collection and conduction of current and constitute an important electrical connection structure inside the battery cell. One end of the positive electrode ear 21 is connected to the positive electrode current collector 23, and the other end is electrically connected to the first pole 32; one end of the negative electrode ear 22 is connected to the negative electrode current collector 24, and the other end is electrically connected to the second pole 33, which is used to convert the internal chemical energy of the battery cell into electrical energy and transmit it to the external circuit through the pole.

[0050] In particular, the dimensions of the positive electrode ear 21 and the negative electrode ear 22 are optimized in this embodiment to improve the current transmission efficiency and balance the thermal management performance. Specifically, the thickness of the positive electrode ear 21 is the same as the thickness of the negative electrode ear 22, ensuring the basic consistency of the mechanical strength and conductive performance of the two. In addition, the length of the positive electrode ear 21 is the same as the length of the negative electrode ear 22, which can reduce the alignment error in manufacturing and assembly, and further improve the assembly accuracy and overall reliability of the battery. Figure 3 The Y direction is the thickness direction of the tab, and the Z2 direction is the length direction of the tab.

[0051] In order to compensate for the difference in material conductivity, the width of the positive electrode tab 21 is designed to be greater than the width of the negative electrode tab 22 . Figure 3 The X direction is the width direction of the pole ear. Since the positive pole ear 21 is usually made of aluminum and the negative pole ear 22 is made of copper, the resistivity of aluminum is higher than that of copper, which means that when the same current passes through, the aluminum positive pole ear 21 will generate greater resistance heat. By increasing the width of the positive pole ear 21, its resistance can be effectively reduced, and the current transmission capacity can be enhanced, thereby reducing the heating problem caused by resistance. At the same time, the increase in width also improves the heat dissipation performance of the positive pole ear 21, which helps to disperse the heat more evenly and further reduce the risk of temperature rise.

[0052] In this embodiment, the present application compensates for the poor electrical conductivity of aluminum by increasing the width of the positive tab 21 without increasing the complexity of the battery, making the positive and negative tabs 22 more balanced in current conduction capacity, and effectively reducing the current deviation and temperature difference in the battery cell assembly 20. In addition, the consistency of the thickness and length of the positive and negative tabs 22 enables standardized operations to be achieved during production and assembly, reducing manufacturing complexity and cost, while enhancing the consistency and reliability of the assembly.

[0053] Furthermore, in order to optimize the conductivity and thermal management of the positive and negative tabs 22, the present application precisely controls the ratio of the width of the positive tab 21 to the width of the negative tab 22. Specifically, the ratio of the width of the positive tab 21 to the width of the negative tab 22 is set to n, and the range is limited to 1.11≤n≤1.14.

[0054] In this embodiment, the width ratio n of the positive electrode ear 21 and the negative electrode ear 22 is controlled within the range of 1.11 to 1.14, which can effectively balance the difference in conductivity between the positive and negative electrode ears 22, while ensuring that the battery structure is compact and the thermal management performance is good. Specifically, when the ratio n is close to 1.11, the width of the positive electrode ear 21 increases slightly, which can provide a certain degree of conductivity compensation compared to the negative electrode ear 22, but when charging and discharging at high rates or working for a long time, the conductivity difference between the positive and negative electrode ears 22 may still exist, which may cause a slightly higher local temperature rise. When the ratio n is close to 1.14, the width of the positive electrode ear 21 increases significantly, which can not only fully compensate for the conductivity gap of the aluminum material, but also enhance its heat dissipation capacity and effectively reduce the temperature difference between the positive and negative electrode ears 22. However, too large a width may occupy more structural space and have a certain impact on the compactness of the battery. Therefore, controlling n within the range of 1.11≤n≤1.14 not only achieves the best matching of the positive and negative electrode ears 22 in terms of conductivity, but also strikes a balance between thermal management and space utilization.

[0055] For further information, see Figure 5 , Figure 5 The middle S region is the contact area between the tab and the pole. The present application optimizes the contact area between the tab and the pole. Specifically, the contact area between the positive tab 21 and the first pole 32 is larger than the contact area between the negative tab 22 and the second pole 33, so as to effectively alleviate the imbalance in the conductivity between the tabs, thereby improving the uniformity and stability of the overall battery performance.

[0056] If the contact area between the positive electrode tab 21 and the first electrode post 32 is equal to the contact area between the negative electrode tab 22 and the second electrode post 33, when the same current passes through, the aluminum part will produce a higher contact resistance, which will cause heat accumulation and may cause the problem of excessive temperature rise.

[0057] In this embodiment, by increasing the contact area between the positive electrode tab 21 and the first electrode 32, the current density per unit area can be reduced, the contact resistance and heat generation can be reduced, the temperature difference between the positive and negative electrodes can be reduced, and the thermal stability and safety of the battery can be improved.

[0058] In some embodiments, specific adjustments are made to the positive electrode current collector 23 and the negative electrode current collector 24 to improve the performance unevenness problem caused by differences in material properties.

[0059] See also Figure 6 , Figure 6 The Z3 direction is the thickness direction of the current collector, and the reference plane C2 is perpendicular to the Z3 direction.

[0060] Specifically, the thickness direction of the positive current collector 23 is parallel to the thickness direction of the negative current collector 24, and the projected area of ​​the positive current collector 23 on the reference plane C2 is equal to the projected area of ​​the negative current collector 24 on the reference plane C2. The thickness of the positive current collector 23 is designed to be greater than the thickness of the negative current collector 24, thereby compensating for the lack of conductive properties of the positive current collector 23 material. The reference plane C2 is defined as a plane perpendicular to the thickness direction of the positive current collector 23 and the negative current collector 24, which is a reference plane for studying the projected area of ​​the positive and negative current collectors 24.

[0061] In this design, the positive electrode current collector 23 is usually made of aluminum, while the negative electrode current collector 24 is made of copper. Since the electrical conductivity (i.e., electrical conductivity) of aluminum is lower than that of copper, when the same current passes through, the aluminum current collector needs to be thicker to reduce its resistance and ensure that the current distribution between the positive and negative electrode current collectors 24 is balanced.

[0062] In this embodiment, the thickness directions of the positive current collector 23 and the negative current collector 24 are parallel to each other. On the reference plane C2, the projected areas of the positive current collector 23 and the negative current collector 24 are equal, ensuring the structural balance of the positive and negative current collectors 24. The symmetry of the arrangement of the two inside the battery is ensured. It helps to balance the current distribution inside the battery cell, reduce the current concentration phenomenon, thereby avoiding local overheating problems and improving the thermal management performance of the battery. The positive current collector 23 compensates for the poor electrical conductivity of aluminum by increasing its thickness, which not only reduces the overall resistance of the positive electrode part, but also significantly reduces the heat generated by the resistance.

[0063] Furthermore, in order to effectively reduce the thickness waste of the positive electrode aluminum foil while ensuring the current capacity of the positive electrode, thereby improving the battery performance and further improving the space utilization efficiency in the thickness direction of the battery cell, the present application accurately controls the thickness ratio of the two to satisfy h = thickness of the positive electrode collector 23 / thickness of the negative electrode collector 24, where 1.15≤h≤1.17.

[0064] In this embodiment, the positive current collector 23 needs to compensate for the lack of electrical conductivity of the aluminum material by moderately increasing the thickness. However, excessive thickness not only increases the material cost, but may also have a negative impact on the energy density and internal space utilization of the battery. Therefore, it is necessary to strike a balance between electrical conductivity, material usage, and space utilization. When the thickness of the positive current collector 23 is 1.15 to 1.17 times the thickness of the negative current collector 24, the positive current collector 23 has a current flow capacity close to that of the negative current collector 24. At the same time, the use of aluminum foil is effectively reduced, avoiding material waste due to excessive thickness, and providing more space for positive and negative active materials, further improving the energy density of the battery cell.

[0065] The embodiment of the present invention further provides a battery pack, which includes the battery of the above design, and utilizes the structural advantages and performance optimization of the battery to significantly improve the overall performance of the battery pack.

[0066] In this embodiment, the battery pack is composed of multiple battery cells, which are connected in series, in parallel or in a mixed manner to achieve the required voltage and capacity output. Due to the battery structure provided by the present invention, the battery pack is significantly optimized in terms of conductivity, thermal management and space utilization.

[0067] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0068] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element through an intermediate element.

[0069] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0070] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A battery, characterized in that: include: A shell body having a receiving cavity and an opening communicating with the receiving cavity; A battery cell assembly is disposed in the accommodating cavity; A battery cover, comprising a cover body, a first pole and a second pole, wherein the cover body covers the opening, the first pole and the second pole are electrically connected to the battery cell assembly respectively, the cover body is provided with a mounting hole, the first pole and the second pole are inserted into the mounting hole, and the conductivity of the material of the first pole is lower than the conductivity of the material of the second pole; The length direction of the first pole and the length direction of the second pole are parallel to each other, and the length of the first pole is equal to the length of the second pole, the projection area of ​​the first pole on the reference plane C1 is larger than the projection area of ​​the second pole on the reference plane C1, and the reference plane C1 is perpendicular to the length direction of the first pole and the length direction of the second pole; Or the length direction of the first pole and the length direction of the second pole are parallel to each other, and the projection area of ​​the first pole on the reference plane C1 is equal to the projection area of ​​the second pole on the reference plane C1, the length of the first pole is less than the length of the second pole, and the reference plane C1 is perpendicular to the length direction of the first pole and the length direction of the second pole.

2. A battery according to claim 1, characterized in that: The ratio of the projection area of ​​the first pole on the reference plane C1 to the projection area of ​​the second pole on the reference plane C1 is m, and 1.11≤m≤1.

14.

3. A battery according to claim 1, characterized in that: The first pole or the second pole includes a pole portion and a connecting portion, the pole portion and the connecting portion are integrally formed, and the connecting portion is used to connect the pole portion and the battery cell assembly.

4. A battery according to claim 3, characterized in that: The connecting portion includes a clamping end and a connecting end that are connected to each other, the clamping end is used to clamp and connect the battery cell assembly, and the connecting end connects the clamping end and the pole portion.

5. A battery according to any one of claims 1 to 4, characterized in that: The battery cell assembly comprises a positive electrode ear, a positive electrode current collector, a negative electrode ear and a negative electrode current collector, wherein the positive electrode ear is respectively connected to the positive electrode current collector and the first electrode column, and the negative electrode ear is respectively connected to the negative electrode current collector and the second electrode column; The thickness of the positive electrode ear is the same as that of the negative electrode ear, the length of the positive electrode ear is the same as that of the negative electrode ear, and the width of the positive electrode ear is greater than that of the negative electrode ear.

6. A battery according to claim 5, characterized in that: The ratio of the width of the positive electrode ear to the width of the negative electrode ear is n, and 1.11≤n≤1.

14.

7. A battery according to claim 6, characterized in that: The contact area between the positive electrode tab and the first electrode column is greater than the contact area between the negative electrode tab and the second electrode column.

8. A battery according to claim 5, characterized in that: The thickness direction of the positive current collector is parallel to the thickness direction of the negative current collector, the projected area of ​​the positive current collector on the reference plane C2 is equal to the projected area of ​​the negative current collector on the reference plane C2, the thickness of the positive current collector is greater than the thickness of the negative current collector, and the reference plane C2 is perpendicular to the thickness direction of the positive current collector and the thickness direction of the negative current collector.

9. A battery according to claim 8, characterized in that: The ratio of the thickness of the positive electrode current collector to the thickness of the negative electrode current collector is h, and 1.15≤h≤1.

17.

10. A battery pack, characterized in that: A battery comprising any one of claims 1 to 9.

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