Pole piece, single battery and battery

Abstract

The utility model provides a pole piece, a single battery and a battery, the pole piece comprises a current collector and an active material layer, the current collector comprises a main body part, the main body part extends towards two sides to form two protruding parts, meanwhile, the main body part further extends outwards to form a pole lug, and the pole lug and one protruding part are located on the same side of the current collector. Therefore, the protruding part is formed in the area, where the tab is not arranged, of the main body part, and the arrangement of the tab and the connection between the tab and other parts cannot be affected by the arrangement of the protruding part. When the pole piece is applied to the battery, the protruding part protruding out of the main body part can occupy the space between the main body part and the cover plate, so that the spare space between the main body part and the cover plate can be effectively utilized, and the space utilization rate in the battery is improved; the active material layer is arranged on the surfaces of the main body part and each protruding part, so that the coating area of the active material layer can be increased, and the volume energy density of the battery is further improved.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an electrode, a single cell, and a battery. Background Technology

[0002] Lithium-ion batteries have advantages such as high specific energy, high operating voltage, low self-discharge rate, small size, and light weight, and are widely used in consumer electronics. However, with the rapid development of electric vehicles and mobile electronic devices, people have increasingly higher demands for batteries in terms of energy density, power density, safety, durability, and cycle performance.

[0003] However, the internal space utilization rate of existing lithium-ion batteries is low. How to improve the internal space utilization rate of batteries and thus improve the volumetric energy density of batteries is an urgent problem to be solved. Utility Model Content

[0004] In view of this, the purpose of this application is to provide an electrode, a single cell, and a battery to solve or partially solve the problems raised in the prior art.

[0005] For the purposes described above, the first aspect of this application provides an electrode sheet, comprising:

[0006] The current collector includes a main body, two protrusions extending from the main body to both sides, and an electrode extending outward from the main body, wherein the electrode and one of the protrusions are located on the same side of the current collector.

[0007] An active material layer is disposed on the surface of the main body and each of the protrusions.

[0008] A second aspect of this application provides a battery cell including an electrode assembly. The electrode assembly includes a first electrode, a second electrode, and a separator located between the first electrode and the second electrode. The first electrode has a first tab, and the second electrode has a second tab. The first tab and the second tab are located on both sides of the electrode assembly. At least one of the first electrode and the second electrode is an electrode as described in the first aspect above.

[0009] Optionally, it also includes:

[0010] A housing having two openings that are oppositely disposed thereon;

[0011] The cover plate is provided in two parts, and the two cover plates correspond one-to-one with the two openings. The cover plate is used to seal the corresponding opening. The cover plate and the housing together form the receiving space. The receiving space contains the electrode assembly. The cover plate is provided with an electrode post, which is connected to the first electrode tab or the second electrode tab.

[0012] An insulating element is located between the electrode assembly and the cover plate, and the insulating element contacts the side of the protrusion closest to the cover plate.

[0013] Optionally, the insulating member includes an annular support portion, the side of the annular support portion near the electrode assembly contacting the side of the protrusion near the cover plate, the orthographic projection of the edge of the protrusion on a first plane being located within the orthographic projection of the annular support portion on the first plane, or coinciding with the orthographic projection of the outer edge of the annular support portion on the first plane, the first plane being perpendicular to the extension direction of the protrusion.

[0014] Optionally, the internal space formed by the annular support portion is a first space, and the size of the first space is greater than or equal to 0.3 mm in the extending direction of the protrusion.

[0015] Optionally, the insulating member includes an insulating support portion, and a second space is formed on the side of the insulating support portion near the electrode assembly. The second space includes a first subspace and a second subspace that are connected. The first subspace is disposed near the electrode assembly, and the inner diameter of the first subspace is larger than the inner diameter of the second subspace. At least a portion of the protrusion extends into the first subspace.

[0016] Optionally, the orthographic projection of the protrusion on the first plane is greater than the orthographic projection of the second subspace on the first plane, and the first plane is perpendicular to the extension direction of the protrusion.

[0017] Optionally, in the extending direction of the protrusion, the size of the second subspace is greater than or equal to 0.3 mm.

[0018] Optionally, the cover plate includes a cover plate boss that protrudes in a direction away from the electrode assembly, and the side of the insulating support portion away from the electrode assembly is connected to the cover plate boss.

[0019] A third aspect of this application provides a battery, including a single cell battery as described in any of the second aspects above.

[0020] As can be seen from the above, the electrode sheet, single cell, and battery provided in this application include an electrode sheet comprising a current collector and an active material layer. The current collector includes a main body portion, which extends to both sides to form two protrusions. Simultaneously, the main body portion also extends outward to form a tab, with the tab and a protrusion located on the same side of the current collector. Thus, the protrusion is formed in an area of ​​the main body portion where no tab is provided, and the protrusion does not affect the tab's placement or its connection to other components. When the electrode sheet is applied to a battery, the protrusions extending from the main body portion can occupy the space between the main body portion and the cover plate, effectively utilizing the empty space between the main body portion and the cover plate, greatly improving the internal space utilization rate of the battery. The active material layer, located on the surface of the main body portion and each protrusion, increases the coating area of ​​the active material layer, thereby increasing the volumetric energy density of the battery. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the electrode structure according to an embodiment of this application is shown;

[0023] Figure 2 A schematic diagram of the current collector structure according to an embodiment of this application is shown;

[0024] Figure 3 An explosion diagram of a battery according to an embodiment of this application is shown;

[0025] Figure 4 A cross-sectional schematic diagram of a battery according to an embodiment of this application is shown;

[0026] Figure 5 It shows Figure 4 A magnified view of part A in the diagram;

[0027] Figure 6 It shows Figure 4 A magnified view of part A in the diagram.

[0028] In the figure: 1. Electrode; 11. Current collector; 111. Main body; 112. Protrusion; 113. Tab; 12. Active material layer; 2. Shell; 3. Electrode assembly; 31. First tab; 32. Second tab; 4. Insulator; 41. Annular support; 42. First space; 43. Insulating support; 44. Second space; 441. First subspace; 442. Second subspace; 5. Cover plate; 51. Cover plate boss; 6. Electrode post; 7. Adapter plate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0030] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] The electrode assembly of a battery is mainly formed by stacking or winding a first electrode and a second electrode with opposite polarities, and a separator is usually provided between the first electrode and the second electrode. The portions of the first and second electrodes coated with active material constitute the active body of the electrode assembly, while the portions of the first and second electrodes not coated with active material constitute the first tab and the second tab, respectively. In a lithium-ion battery, the first electrode can be a positive electrode, including a positive current collector and a layer of positive active material disposed on the surface of the positive current collector. The material of the positive current collector can be, for example, aluminum, and the positive active material can be, for example, lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.; the second electrode can be a negative electrode, including a negative current collector and a layer of negative active material disposed on the surface of the negative current collector. The material of the negative current collector can be, for example, copper, and the negative active material can be, for example, graphite or silicon, etc.

[0032] The existing first and second electrodes have flush sides on all sides of their active bodies, and are formed by extending outward from one side of the active body. During the assembly of the electrode assembly and the cover plate assembly, the first and second electrodes are connected to the corresponding electrodes on the cover plate assembly.

[0033] However, since the first and second tabs are set out from the active body, after the tabs are connected to the terminal post, there is still a large amount of unused space between the part of the active body without tabs and the cover plate. The existence of this space leads to insufficient space utilization inside the battery, resulting in insufficient volumetric energy density of the battery.

[0034] Therefore, how to further improve the space utilization rate inside the battery, and thus improve the volumetric energy density of the battery, is an urgent problem to be solved.

[0035] Based on this, this application provides an electrode, a single cell, and a battery.

[0036] Figure 1 A schematic diagram of the structure of electrode 1 according to an embodiment of this application is shown. Figure 2 A schematic diagram of the current collector 11 according to an embodiment of this application is shown.

[0037] See Figure 1 and Figure 2 As shown, the electrode 1 provided in this application includes: a current collector 11, including a main body 111, two protrusions 112 extending from the main body 111 to both sides, and an electrode tab 113 extending outward from the main body 111, wherein the electrode tab 113 and a protrusion 112 are located on the same side of the current collector 11; and an active material layer 12 disposed on the surface of the main body 111 and each protrusion 112.

[0038] Specifically, along the length of the main body 111, two protrusions 112 extend to both sides of the main body 111, and a tab 113 also extends outward from the main body 111. The tab 113 and the protrusion 112 are located on the same side of the current collector 11. Thus, the protrusion 112 is formed in the area of ​​the main body 111 where the tab 113 is not provided, and the provision of the protrusion 112 does not affect the provision of the tab 113 or the connection of the tab 113 with other components. When the electrode 1 is applied to the battery, the tab 113 is connected to the terminal post 6 on the cover plate 5. At this time, the protrusion 112 protruding from the main body 111 can occupy the space between the main body 111 and the cover plate 5. In this way, the empty space between the main body 111 and the cover plate 5 can be effectively utilized, greatly improving the space utilization rate inside the battery.

[0039] Furthermore, the main body 111 extends to both sides to form two protrusions 112. In this way, the two protrusions 112 can occupy the space between the main body 111 and the two cover plates 5 respectively, which can greatly improve the space utilization rate inside the battery.

[0040] The active material layer 12 is disposed on the surface of the main body 111 and each protrusion 112. Thus, compared with the existing active material layer 12 which is only disposed on the electrode 1 of the main body 111, the active material layer 12 disposed on the surface of the main body 111 and each protrusion 112 in this application can greatly increase the coating area of ​​the active material layer 12, thereby greatly improving the volumetric energy density of the battery.

[0041] Figure 3 An explosion diagram of a battery according to an embodiment of this application is shown. Figure 4 A cross-sectional schematic diagram of a battery according to an embodiment of this application is shown.

[0042] See Figure 3 and Figure 4 As shown, this application also provides a battery cell including an electrode assembly 3. The electrode assembly 3 includes a first electrode, a second electrode, and a separator located between the first electrode and the second electrode. The first electrode has a first tab 31, and the second electrode has a second tab 32. The first tab 31 and the second tab 32 are located on both sides of the electrode assembly 3. At least one of the first electrode and the second electrode is the electrode 1 of the above embodiment.

[0043] Specifically, in this embodiment, the first electrode can be electrode 1 of the above embodiment, the second electrode can be electrode 1 of the above embodiment, or both the first electrode and the second electrode can be electrode 1 of the above embodiment.

[0044] When both the first electrode and the second electrode are electrode 1 as described in the above embodiment, the internal volume space utilization of the battery is maximized, and the volumetric energy density of the battery is also maximized.

[0045] In some embodiments, see continue to see Figure 3 and Figure 4 As shown, the battery cell also includes:

[0046] Housing 2, housing 2 has two openings that are arranged opposite to each other;

[0047] Two cover plates 5 are provided, and the two cover plates 5 correspond one-to-one with two openings. The cover plates 5 are used to seal the corresponding openings. The cover plates 5 and the housing 2 enclose a receiving space, which contains the electrode assembly 3. The cover plates 5 are provided with pole posts 6, which are connected to the first pole tab 31 or the second pole tab 32.

[0048] The insulating element 4 is located between the electrode assembly 3 and the cover plate 5, and the insulating element 4 is in contact with the side of the protrusion 112 near the cover plate 5.

[0049] Specifically, the cover plate 5 is insulated with a pole post 6. Of the two cover plates 5, the pole post 6 on one cover plate 5 is connected to the first tab 31, and the pole post 6 on the other cover plate 5 is connected to the second tab 32. Furthermore, the connection between the first tab 31 or the second tab 32 and the pole post 6 can be achieved through an adapter piece 7.

[0050] The insulating element 4 is made of insulating material, and there are two insulating elements 4, one between each cover plate 5 and electrode assembly 3. The insulating element 4 contacts the side of the protrusion 112 closest to the cover plate 5. On the one hand, the insulating element 4 can support the protrusion 112 to prevent the protrusion 112 and the entire electrode 1 from moving within the receiving space; on the other hand, the insulating element 4 can prevent the protrusion 112 from directly contacting the cover plate 5 to avoid short circuit.

[0051] Figure 5 It shows Figure 4 A magnified view of part A in the diagram.

[0052] In some embodiments, see Figure 5 As shown, the insulating member 4 includes an annular support portion 41. The side of the annular support portion 41 near the electrode assembly 3 contacts the side of the protrusion 112 near the cover plate 5. The orthographic projection of the edge of the protrusion 112 on the first plane is located in the orthographic projection of the annular support portion 41 on the first plane, or coincides with the orthographic projection of the outer edge of the annular support portion 41 on the first plane. The first plane is perpendicular to the extension direction of the protrusion 112.

[0053] Specifically, the side of the annular support 41 near the electrode assembly 3 contacts the side of the protrusion 112 near the cover plate 5. In this way, the annular support 41 can support the protrusion 112, and the insulating member 4 can support the protrusion 112 to prevent the protrusion 112 and the entire electrode 1 from moving within the accommodating space.

[0054] The orthographic projection of the edge of the protrusion 112 on the first plane lies within the orthographic projection of the annular support 41 on the first plane. Thus, the annular support 41 not only covers the edge of the protrusion 112 but also protrudes beyond a portion of the edge of the protrusion 112, ensuring that the annular support 41 can effectively support the entire protrusion 112. This avoids the situation where some parts of the protrusion 112 are not supported and limited due to partial support, ensuring that the position of the entire protrusion 112 and the entire electrode 1 is limited and will not move, thereby improving the structural stability of the electrode assembly 3.

[0055] Alternatively, the orthographic projection of the edge of the protrusion 112 on the first plane coincides with the orthographic projection of the outer edge of the annular support 41 (i.e., the outer edge of the annular structure) on the first plane. In this way, the outer edge of the annular support 41 and the edge of the protrusion 112 are exactly flush, ensuring that the annular support 41 can effectively support the entire protrusion 112. This avoids the situation where some parts of the protrusion 112 are not supported and limited due to partial support, ensuring that the position of the entire protrusion 112 and the entire electrode 1 is limited and will not move, thereby improving the structural stability of the electrode assembly 3.

[0056] In some embodiments, see continue to see Figure 5 As shown, the internal space formed by the annular support 41 is the first space 42. In the extending direction of the protrusion 112, the size of the first space 42 is greater than or equal to 0.3 mm.

[0057] Specifically, when the side of the annular support 41 near the electrode assembly 3 contacts the side of the protrusion 112 near the cover plate 5, the first space 42 is the gap between the protrusion 112 and the surface of the cover plate 5 near the electrode assembly 3. This gap is provided to accommodate the venting inside the battery and ensure the normal use of the battery.

[0058] The size of the first space 42 is greater than or equal to 0.3 mm to ensure that the size of the first space 42 is sufficient to accommodate the venting and gas generation of the battery, thus ensuring the normal use of the battery.

[0059] If the size of the first space 42 is less than 0.3mm, the size of the first space 42 is too small, so that the first space 42 cannot accommodate the exhaust gas of the battery. As a result, the gas generated inside the battery will impact the casing 2 and the cover plate 5, which may cause the casing 2 and the cover plate 5 to deform, thereby reducing the sealing performance of the battery and which is not conducive to the long-term use of the battery.

[0060] Figure 6 It shows Figure 4 A magnified view of part A in the diagram.

[0061] In some embodiments, the insulating member 4 includes an insulating support portion 43, and a second space 44 is formed on the side of the insulating support portion 43 near the electrode assembly 3. The second space 44 includes a first subspace 441 and a second subspace 442 that are connected. The first subspace 441 is disposed near the electrode assembly 3, and the inner diameter of the first subspace 441 is larger than the inner diameter of the second subspace 442. At least a portion of the protrusion 112 extends into the first subspace 441.

[0062] Specifically, at least a portion of the protrusion 112 extends into the first subspace 441, thereby providing more accommodating volume for the protrusion 112. The dimensions of the protrusion 112 in its extending direction can be further increased, thereby further improving the internal volume utilization rate of the battery and further improving the volumetric energy density of the battery.

[0063] Meanwhile, since the inner diameter of the first subspace 441 is larger than the inner diameter of the second subspace 442, at least part of the protrusion 112 can not go deeper into the second subspace 442 after it extends into the first subspace 441. In this way, a certain gap can be reserved between the protrusion 112 and the surface of the cover plate 5 near the electrode assembly 3 to ensure that there is still space inside the battery to accommodate the gas produced by the battery, so as to utilize the actual use of the battery.

[0064] In some embodiments, the orthographic projection of the protrusion 112 on the first plane is greater than the orthographic projection of the second subspace 442 on the first plane, and the first plane is perpendicular to the extension direction of the protrusion 112.

[0065] Specifically, the orthographic projection of the protrusion 112 on the first plane is larger than the orthographic projection of the second subspace 442 on the first plane. Thus, the size of the protrusion 112 is larger and the size of the second subspace 442 is smaller, ensuring that at least part of the protrusion 112 can not go further into the second subspace 442 after it extends into the first subspace 441. In this way, the second subspace 442 is the gap reserved between the protrusion 112 and the surface of the cover plate 5 near the electrode assembly 3, ensuring that there is still space inside the battery to accommodate the gas generated by the battery, which is beneficial for the actual use of the battery.

[0066] In some embodiments, the size of the second subspace 442 is greater than or equal to 0.3 mm in the extending direction of the protrusion 112.

[0067] Specifically, since the second subspace 442 is the gap reserved between the protrusion 112 and the surface of the cover plate 5 near the electrode assembly 3, the gap is set to accommodate the venting inside the battery and ensure the normal use of the battery.

[0068] The size of the second subspace 442 is greater than or equal to 0.3 mm to ensure that the size of the second subspace 442 is sufficient to accommodate the venting and gas generation of the battery, thus ensuring the normal use of the battery.

[0069] If the size of the second subspace 442 is less than 0.3mm, the size of the second subspace 442 is too small, so that the second subspace 442 cannot accommodate the exhaust gas of the battery. As a result, the gas generated inside the battery will impact the casing 2 and the cover plate 5, which may cause the casing 2 and the cover plate 5 to deform, thereby reducing the sealing performance of the battery and which is not conducive to the long-term use of the battery.

[0070] In some embodiments, the cover plate 5 includes a cover plate boss 51 that protrudes in the direction away from the electrode assembly 3. The insulating support portion 43 is connected to the cover plate boss 51 on the side away from the electrode assembly 3. Thus, compared to a cover plate 5 without a cover plate boss 51, the protrusion of the cover plate boss 51 in the direction away from the electrode assembly 3 increases the space on the side of the cover plate boss 51 close to the electrode assembly 3, thereby increasing the space of the insulating support portion 43 for forming the second space 44. In this way, the volume of the first subspace 441 can be increased based on the increased second space 44. The increased first subspace 441 can accommodate a larger protrusion 112. The larger protrusion 112 can further improve the internal volume utilization rate and volumetric energy density of the battery.

[0071] This application also provides a battery, including the single-cell battery of any of the above embodiments.

[0072] Specifically, a battery can contain multiple individual cells, which can be connected in series, parallel, or a combination thereof. A combination of series and parallel connections refers to multiple individual cells being connected in both series and parallel configurations. Multiple individual cells can be directly connected in series, parallel, or a combination thereof, and then the entire assembly is housed within a casing. Alternatively, a battery can consist of multiple individual cells first connected in series, parallel, or a combination thereof to form a battery module, and then these modules are connected in series, parallel, or a combination thereof to form a single unit housed within a casing. The battery can also include other structures; for example, it can include a busbar component for electrical connection between the multiple individual cells.

[0073] The battery has the technical effects described in any of the above embodiments, and will not be repeated here.

[0074] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of this application as described above, which are not provided in detail for the sake of brevity.

[0075] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pole piece, characterized in that, The current collector comprises a main body, two protruding portions extending from the main body to two sides, and a tab extending from the main body outward, the tab being located on the same side of the current collector as one of the protruding portions. An active material layer is arranged on the surface of the main body and each of the protruding portions. The electrode assembly comprises a first tab, a second tab, and a separator between the first tab and the second tab, the first tab is provided with a first tab, the second tab is provided with a second tab, the first tab and the second tab are located on two sides of the electrode assembly, and at least one of the first tab and the second tab is the tab of claim 1.

2. A battery cell characterized by, Further comprising:

3. The battery cell of claim 2, wherein, A housing is provided with two opposite openings; Two cover plates are provided, one-to-one corresponding to the two openings, the cover plates are used to seal the corresponding openings, the cover plates and the housing form a containing space, the containing space contains the electrode assembly, the cover plates are provided with a pole, and the pole is connected with the first tab or the second tab; An insulating piece is located between the electrode assembly and the cover plate, and the insulating piece is in contact with the side of the protruding portion close to the cover plate. The insulating piece comprises a ring-shaped support portion, the side of the ring-shaped support portion close to the electrode assembly is in contact with the side of the protruding portion close to the cover plate, the edge of the protruding portion is located in the projection of the ring-shaped support portion on a first plane, or the edge of the protruding portion coincides with the outer edge of the ring-shaped support portion on the first plane, and the first plane is perpendicular to the extension direction of the protruding portion.

4. The battery cell of claim 3, wherein, The internal space formed by the ring-shaped support portion is a first space, and the size of the first space is greater than or equal to 0.3mm in the extension direction of the protruding portion.

5. The battery cell of claim 4, wherein, The insulating piece comprises an insulating support portion, the side of the insulating support portion close to the electrode assembly forms a second space, the second space comprises a first subspace and a second subspace in communication, the first subspace is arranged close to the electrode assembly, the inner diameter of the first subspace is greater than that of the second subspace, and at least part of the protruding portion extends into the first subspace.

6. The battery cell of claim 3, wherein, The projection of the protruding portion on a first plane is greater than the projection of the second subspace on the first plane, and the first plane is perpendicular to the extension direction of the protruding portion.

7. The battery cell of claim 6, wherein, The size of the second subspace is greater than or equal to 0.3mm in the extension direction of the protruding portion.

8. The battery cell of claim 7, wherein, The cover plate comprises a cover plate boss, the cover plate boss protrudes away from the electrode assembly, and the side of the insulating support portion away from the electrode assembly is connected with the cover plate boss.

9. The battery cell of claim 6, wherein, 10. A battery comprising the single battery cell of any one of claims 2-9. ​

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