Battery cell and battery pack

Abstract

The utility model describes a battery cell and a battery pack, the battery cell comprises a positive pole lug and a positive pole post, the positive pole lug is provided with a positive pole welding and printing area, and the positive pole welding and printing area is connected with the positive pole post; the negative electrode tab is provided with a negative electrode welding and printing area, and the negative electrode welding and printing area is connected with the negative electrode post; wherein the positive electrode tab is made of first metal, the negative electrode tab is made of second metal, the conductivity of the first metal is smaller than that of the second metal, and the area of the positive electrode welding and printing area is larger than that of the negative electrode welding and printing area. Therefore, the current over-current capacity of the positive electrode lug is weaker than that of the negative electrode lug, and the area of the positive electrode welding printing area is larger than that of the negative electrode welding printing area, so that the current over-current capacity between the positive electrode lug and the negative electrode lug can be balanced, and the balanced distribution of the current between the positive electrode and the negative electrode is realized. According to the structure, the overall performance of the battery cell is improved, a more stable power supply guarantee is provided, and the service life of the battery cell can be prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a kind of battery cell and battery package. BACKGROUND

[0002] Lithium ion battery has the advantages of light weight, good safety performance, etc., and is widely used in electric vehicles and other fields. Among them, the tab is a key component of the battery cell, and the positive tab is usually made of aluminum material, and the negative tab is usually made of copper material. In the battery cell structure, the tab is connected with the pole piece and the pole respectively, and is the carrier of the battery output current. During use of the battery, if the current overcurrent capacity of the positive and negative electrodes of the battery is inconsistent, it may cause the performance of the battery to decline, the service life to be shortened, and the safety risk to be increased. Therefore, the connection structure of the tab is particularly important. SUMMARY

[0003] The utility model provides a kind of battery cell and battery package, which can improve the problem of inconsistent current overcurrent capacity of the positive and negative electrodes of the battery.

[0004] In a first aspect, the utility model provides a battery cell, which includes: a positive tab and a positive pole, the positive tab is provided with a positive soldering area, the positive soldering area is connected with the positive pole; a negative tab and a negative pole, the negative tab is provided with a negative soldering area, the negative soldering area is connected with the negative pole; wherein the positive tab is a first metal, the negative tab is a second metal, the conductivity of the first metal is less than the conductivity of the second metal, and the area of the positive soldering area is greater than the area of the negative soldering area.

[0005] Optionally, the area of the positive soldering area is a first area, the area of the negative soldering area is a second area, the ratio of the first area to the second area is greater than 1.01 and less than or equal to 1.2.

[0006] Optionally, the area of the positive tab is greater than the area of the negative tab.

[0007] Optionally, the area of the positive tab is a third area, the area of the negative tab is a fourth area, the ratio between the third area and the fourth area is greater than 1 and less than or equal to 1.18.

[0008] Optionally, the battery cell further includes a positive connecting piece and a negative connecting piece; the positive connecting piece is connected with the positive soldering area and the positive pole respectively, and the negative connecting piece is connected with the negative soldering area and the negative pole respectively.

[0009] Optionally, the positive soldering area is directly welded with the positive pole, and the negative soldering area is directly welded with the negative pole.

[0010] Optionally, the area of the positive electrode welding pad region is positively correlated with the capacity of the battery cell or the volume of the battery cell.

[0011] Optionally, the ratio between the area of the positive electrode welding pad region and the area of the negative electrode tab is greater than or equal to 5% and less than or equal to 11%; and / or, the ratio between the area of the negative electrode welding pad region and the area of the negative electrode welding pad region is greater than or equal to 5% and less than or equal to 12%.

[0012] Optionally, the battery cell further comprises a battery cell body, the positive electrode tab is connected with the battery cell body, the negative electrode tab is connected with the battery cell body; the positive electrode welding pad region is arranged spaced apart from the battery cell body, and / or the negative electrode welding pad region is arranged spaced apart from the battery cell body.

[0013] In a second aspect, the utility model provides a kind of battery pack, it includes the battery cell as described above.

[0014] The battery cell related by the utility model includes positive electrode tab, negative electrode tab, positive electrode pole and negative electrode pole, positive electrode tab is equipped with positive electrode welding pad region, and positive electrode welding pad region is connected with positive electrode pole;Negative electrode tab is equipped with negative electrode welding pad region, and negative electrode welding pad region is connected with negative electrode pole;Wherein, the first metal of positive electrode tab, the second metal of negative electrode tab, the conductivity of the first metal is less than the conductivity of the second metal, and the area of positive electrode welding pad region is greater than the area of negative electrode welding pad region.Therefore, the current overcurrent capacity of positive electrode tab is weaker than negative electrode tab, and the area of positive electrode welding pad region is set to be larger than negative electrode welding pad region, so as to balance the current overcurrent between positive electrode tab and negative electrode tab, to ensure the stability of battery cell output current, realize the balanced distribution of current between positive electrode and negative electrode.The structure not only improves the overall performance of battery cell, provides more stable power supply guarantee, but also prolongs the service life of battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0016] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0017] Figure 1 It is shown that the overall structure of the battery cell related by the present application.

[0018] Figure 2is a schematic diagram showing the overall structure of the battery cell involved in the present application.

[0019] Figure 3 is a schematic diagram showing the overall structure of the battery cell involved in the present application.

[0020] Figure 4 is a graph showing the relationship between the volume of the battery cell and the area of the positive electrode welding pad area involved in the present application.

[0021] Figure 5 is a graph showing the relationship between the capacity of the battery cell and the area of the positive electrode welding pad area involved in the present application.

[0022] Reference signs: 1, positive electrode tab; 11, positive electrode welding pad area; 2, negative electrode tab; 21, negative electrode welding pad area; 3, battery cell body. DETAILED DESCRIPTION

[0023] Hereinafter, the preferred embodiments of the present application will be described in detail with reference to the accompanying drawings. In the following description, the same parts are given the same reference numerals, and repeated description is omitted. In addition, the drawings are merely schematic diagrams, and the proportions of the sizes of the parts with respect to each other or the shapes of the parts, etc. can be different from the actual ones. It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement, etc. between the parts in a certain specific posture, and if the specific posture changes, the directional indications also change accordingly.

[0024] It should also be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a mediating element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there can be a mediating element.

[0025] Reference Figure 1 , the present application provides a battery cell, comprising a positive electrode tab 1, a positive electrode tab, a negative electrode tab 2 and a negative electrode tab. The positive electrode tab 1 is provided with a positive electrode welding pad area 11, and the positive electrode welding pad area 11 is connected to the positive electrode tab; the negative electrode tab 2 is provided with a negative electrode welding pad area 21, and the negative electrode welding pad area 21 is connected to the negative electrode tab; wherein the area of the positive electrode welding pad area 11 is larger than the area of the negative electrode welding pad area 21. Thus, the current overcurrent capacity of the positive electrode tab 1 is weaker than that of the negative electrode tab 2, and the area of the positive electrode welding pad area 11 is set to be larger than that of the negative electrode welding pad area 21, so as to balance the current overcurrent between the positive electrode tab 1 and the negative electrode tab 2, to ensure the stability of the output current of the battery cell, and to realize the balanced distribution of the current between the positive and negative electrodes. This structure not only improves the overall performance of the battery cell, provides more stable power supply protection, but also prolongs the service life of the battery cell.

[0026] In some embodiments, the positive tab 1 is a first metal and the negative tab 2 is a second metal, and the conductivity of the first metal is less than that of the second metal. Specifically, during the charging and discharging process of the battery, the flow of current puts high requirements on the conductivity of the positive tab 1 and the negative tab 2 to better bear the current output by the battery cell. According to the difference in conductivity between the positive tab 1 and the negative tab 2, the present application sets the area of the positive welding area 11 to be larger than that of the negative welding area 21, thereby improving the current carrying capacity of the positive tab 1 and ensuring that the positive electrode can effectively handle its current demand during the charging and discharging process of the battery, reducing the performance degradation caused by current overload. By increasing the area of the positive welding area 11, the conductive area of the positive tab 1 is also increased, thereby improving its current carrying capacity and ensuring that the positive electrode can effectively handle its current demand during the charging and discharging process of the battery. In addition, this area setting helps to balance the current distribution inside the battery, avoiding uneven temperature inside the battery or local temperature rise caused by uneven current carrying of the positive and negative electrodes, thereby reducing the risk of thermal runaway, improving the safety of the battery, and prolonging the service life of the battery.

[0027] Specifically, the positive tab 1 can be made of aluminum material, and the negative tab 2 can be made of copper material. Among them, both aluminum and copper have excellent electrical conductivity and chemical stability. First, the manufacturing cost of aluminum is relatively low, which helps to reduce the overall production cost of the battery, which is of great significance for large-scale production and market promotion. In addition, the density of aluminum is less than that of copper, and the use of aluminum as the positive tab 1 can reduce the weight of the battery, which is particularly important for portable electronic devices and electric vehicles and other applications, as it helps to improve the energy density and endurance of the battery. In terms of performance, although the conductivity of aluminum is lower than that of copper, its good corrosion resistance is crucial to prolong the service life of the battery. The aluminum surface can form a dense layer of aluminum oxide film, which can effectively prevent further corrosion and ensure stable operation of the battery in harsh environments. On the other hand, the negative tab 2 uses copper material based on the excellent conductivity of copper. The conductivity of copper is higher than that of aluminum, which means that in the negative tab 2, copper can more effectively conduct current, which is crucial for the performance of the battery under high current density. This property of copper enables the negative tab 2 to withstand greater current load, thereby meeting the performance requirements of the battery under high power output demand. Therefore, the design of the positive tab 1 using aluminum material and the negative tab 2 using copper material not only balances the cost and performance, but also improves the safety, durability and environmental friendliness of the battery.

[0028] In some embodiments, the area of the positive welding pad area 11 is a first area, and the area of the negative welding pad area 21 is a second area; the ratio of the first area to the second area is greater than 1.01 and less than or equal to 1.2. In this way, by setting the ratio of the first area to the second area to be between 1.01 and 1.2, the optimization of current distribution is achieved. The difference in current flow capacity between the positive tab 1 and the negative tab 2 is compensated for, which is conducive to maintaining the stability of the battery output current, reducing performance degradation and thermal management problems caused by uneven current, thereby improving the overall performance and service life of the battery. In some examples, the ratio of the first area to the second area can be any of 1.04, 1.06, 1.08, 1.1, 1.2.

[0029] Referring to Figure 2 In some embodiments, the area of the positive tab 1 is greater than the area of the negative tab 2. Specifically, the area of the positive tab 1 is designed to be greater than the area of the negative tab 2, so that the positive tab 1 can be provided with a larger area, so that the positive welding pad area 11 can also be provided with a larger area, so that the positive tab 1 can more effectively carry the current during the charging and discharging process, thereby improving the overall performance and reliability of the battery.

[0030] In some examples, the width of the positive tab 1 can be greater than the width of the negative tab 2, such as Figure 2 The width of the positive tab 1 can be d1, and the width of the negative tab 2 can be d2, d1>d2.

[0031] In some embodiments, the area of the positive tab 1 is a third area, and the area of the negative tab 2 is a fourth area; the ratio between the third area and the fourth area is greater than 1 and less than or equal to 1.18. In some examples, the ratio between the third area and the fourth area can be any of 1.0, 1.08, 1.1, 1.15, 1.18.

[0032] In some embodiments, the battery cell further comprises a positive connecting piece and a negative connecting piece; the positive connecting piece is connected with the positive welding pad area 11 and the positive tab respectively, and the negative connecting piece is connected with the negative welding pad area 21 and the negative tab respectively. Specifically, the tab connecting piece is a component for leading out current. In this embodiment, the positive connecting piece can be welded with the positive welding pad area 11 and the positive tab respectively, and the negative connecting piece can be welded with the negative welding pad area 21 and the negative tab respectively, to ensure the connectivity and stability of the internal circuit of the battery.

[0033] In some embodiments, the positive electrode pad area 11 is directly welded with the positive electrode post; the negative electrode pad area 21 is directly welded with the negative electrode post. Thus, in the present embodiments, no tab adapter is needed to be arranged in the battery cell. First, the setting step of the tab adapter is omitted, greatly simplifying the production and manufacturing process of the battery cell. The traditional battery cell manufacturing process involves multiple complex steps, and simplification makes the production process more direct and efficient. This not only reduces the production time, but also reduces the production cost. Second, the design without the tab adapter reduces the use of materials. As an electronic component, the production and installation of the tab adapter consumes a certain amount of material resources. By omitting this component, material waste in the battery manufacturing process can be significantly reduced, which is of great significance to environmental protection and resource conservation. In addition, the presence of the tab adapter can become a potential failure point, and the present design directly connects the tab and the internal electrode, reducing the connection points and thus reducing the risk of battery failure during use. The production and manufacturing process of the battery cell is simpler and more material-saving.

[0034] Referring to Figure 4 and Figure 5 In some embodiments, the area of the positive electrode pad area 11 is positively correlated with the capacity or volume of the battery cell. Thus, the larger the capacity or volume of the battery cell, the greater the current flow of the positive electrode tab 1. Specifically, as the capacity of the battery cell increases, the volume of the battery cell will also increase accordingly. In addition, in order to make the structure of the battery cell more compact, there is usually no redundant space in the battery cell, so the increase in the volume of the battery cell usually also increases the capacity of the battery cell. Accordingly, the area of the positive electrode pad area 11 is positively correlated with the capacity of the battery cell, or the area of the positive electrode pad area 11 is positively correlated with the volume of the battery cell.

[0035] In some embodiments, the area of the positive electrode pad area 11 and the capacity or volume of the battery cell can be set as follows: when 50 Ah < capacity of the battery cell < 150 Ah or 700 cm3 < volume of the battery cell < 2000 cm3, 60 mm2 < area of the positive electrode pad area 11 < 80 mm2; when 150 Ah < capacity of the battery cell < 250 Ah or 2000 cm3 < volume of the battery cell < 2400 cm3, 80 mm2 < area of the positive electrode pad area 11 < 100 mm2; when 250 Ah < capacity of the battery cell < 350 Ah or 2400 cm3 < volume of the battery cell < 3000 cm3, 100 mm2 < area of the positive electrode pad area 11 < 120 mm2; when 350 Ah < capacity of the battery cell < 500 Ah or 3000 cm3 < volume of the battery cell < 4000 cm3, 120 mm2 < area of the positive electrode pad area 11 < 80 mm2; when 500 Ah < capacity of the battery cell < 700 Ah or 4000 cm3 < volume of the battery cell < 6000 cm3, 150 mm2 < area of the positive electrode pad area 11 < 190 mm2. 3 ≤ volume of the battery cell < 2400 cm3, 80 mm2 < area of the positive electrode pad area 11 < 100 mm2; when 250 Ah < capacity of the battery cell < 350 Ah or 2400 cm3 < volume of the battery cell < 3000 cm3, 100 mm2 < area of the positive electrode pad area 11 < 120 mm2; when 350 Ah < capacity of the battery cell < 500 Ah or 3000 cm2 < volume of the battery cell < 4000 cm3, 120 mm2 < area of the positive electrode pad area 11 < 80 mm2; when 500 Ah < capacity of the battery cell < 700 Ah or 4000 cm3 < volume of the battery cell < 6000 cm3, 150 mm2 < area of the positive electrode pad area 11 < 190 mm2.

[0036] In some examples, the area of the positive welding pad area 11, the capacity of the electric core, and the volume of the electric core can all float within a range of 4%, which will not significantly affect the performance of the electric core.

[0037] In some embodiments, the ratio between the area of the positive welding pad area 11 and the area of the negative tab 2 is greater than or equal to 5% and less than or equal to 11%. In this way, the positive welding pad area 11 occupies a suitable proportion of the area of the negative tab 2, which not only ensures sufficient connection between the battery post and the positive welding pad area 11, ensuring effective electrical conduction, but also avoids material waste and structural imbalance due to excessive area. The control of this ratio is crucial in battery manufacturing, as it not only optimizes the performance of the battery, improves energy efficiency and cycle life, but also enhances the stability and safety of the battery under extreme working conditions, ensuring the overall reliability of the battery.

[0038] In other embodiments, the ratio between the area of the negative welding pad area 21 and the area of the negative tab 2 is greater than or equal to 5% and less than or equal to 12%. In this way, the negative welding pad area 21 occupies a suitable proportion of the area of the negative tab 2, which not only ensures sufficient connection between the battery post and the negative welding pad area 21, ensuring effective electrical conduction, but also avoids material waste and structural imbalance due to excessive area. The control of this ratio is crucial in battery manufacturing, as it not only optimizes the performance of the battery, improves energy efficiency and cycle life, but also enhances the stability and safety of the battery under extreme working conditions, ensuring the overall reliability of the battery.

[0039] Referring to Figure 3 In some embodiments, the electric core further includes an electric core body 3, the positive tab 1 is connected to the electric core body 3, and the negative tab 2 is connected to the electric core body 3; the positive welding pad area 11 is spaced apart from the electric core body 3. In this way, the positive welding pad area 11 is at a distance from the electric core body 3, ensuring that the welding tool can be safely operated during the welding process without interfering with the electric core body 3, reducing the risk of damage to the electric core body 3 or the welding tool due to collision of the welding tool.

[0040] Referring to Figure 3 In some examples, the distance between the positive welding pad area 11 and the electric core body 3 can be L, and the value of L can be between 10mm and 20mm. In other examples, the distance between the negative welding pad area 21 and the electric core body 3 can also be between 10mm and 20mm.

[0041] In some embodiments, the negative electrode pad area 21 is spaced apart from the cell body 3. In this way, the negative electrode pad area 21 is distanced from the cell body 3, ensuring that the welding tool can be safely operated without interference with the cell body 3 during the welding process, reducing the risk of damage to the cell body 3 or the welding tool caused by collision of the welding tool. In the related art, the cell body 3 is also referred to as a core package or a core roll, which generally includes positive and negative electrode sheets, positive and negative electrode materials, and a separator, and can be formed by winding or stacking, and is a key structure of the cell.

[0042] The application also provides a battery pack comprising the cell as above.

[0043] In summary, in the present application, the current overcurrent capacity of the positive electrode tab 1 is weaker than that of the negative electrode tab 2, and the area of the positive electrode pad area 11 is set to be larger than that of the negative electrode pad area 21, so as to balance the current overcurrent between the positive electrode tab 1 and the negative electrode tab 2, to ensure the stability of the cell output current, and to achieve balanced distribution of current between the positive and negative electrodes. This structure not only improves the overall performance of the cell, provides more stable power supply, but also prolongs the service life of the cell.

[0044] In the description of the present application, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0045] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0046] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0047] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application, without departing from the technical solution of the present application, still falls within the scope of the technical solution of the present application.

[0048] Although the present application has been specifically described above in combination with the drawings and embodiments, it should be understood that the above description does not limit the present application in any form. Those skilled in the art can make deformations and changes to the present application according to needs without deviating from the essential spirit and scope of the present application, and these deformations and changes all fall within the scope of the present application.

Claims

1. An electric cell, characterized by, The battery cell comprises: a positive tab and a positive post, the positive tab being provided with a positive welding area, the positive welding area being connected with the positive post; a negative tab and a negative post, the negative tab being provided with a negative welding area, the negative welding area being connected with the negative post; wherein the positive tab is a first metal, the negative tab is a second metal, the conductivity of the first metal is less than the conductivity of the second metal, and the area of the positive welding area is greater than the area of the negative welding area.

2. The electric cell of claim 1, wherein, The area of the positive welding area is a first area, and the area of the negative welding area is a second area. The ratio of the first area to the second area is greater than 1.01 and less than or equal to 1.

2.

3. The electric cell of claim 1, wherein, The area of the positive tab is greater than the area of the negative tab.

4. The electric cell of claim 1, wherein, The area of the positive tab is a third area, and the area of the negative tab is a fourth area. The ratio of the third area to the fourth area is greater than 1 and less than or equal to 1.

18.

5. The electric cell of claim 1, wherein, The battery cell further comprises a positive connecting piece and a negative connecting piece. The positive connecting piece is connected with the positive welding area and the positive post respectively, and the negative connecting piece is connected with the negative welding area and the negative post respectively.

6. The electric cell of claim 1, wherein, The positive welding area is directly welded with the positive post. The negative welding area is directly welded with the negative post.

7. The cell of any of claims 1-6, wherein, The area of the positive welding area is positively correlated with the capacity of the battery cell or the volume of the battery cell.

8. The cell of any of claims 1-6, wherein, The ratio of the area of the positive welding area to the area of the negative tab is greater than or equal to 5% and less than or equal to 11%; and / or, The ratio of the area of the negative welding area to the area of the negative tab is greater than or equal to 5% and less than or equal to 12%.

9. The cell of any of claims 1-6, wherein, The battery cell further comprises a battery cell body, the positive tab being connected with the battery cell body, and the negative tab being connected with the battery cell body. The positive welding area is spaced apart from the battery cell body, and / or the negative welding area is spaced apart from the battery cell body.

10. A battery pack, characterized by, The battery cell comprises any one of claims 1-9.

Images