A battery electrode, a battery cell and a battery

Abstract

This utility model provides a battery electrode, a battery cell, and a battery, comprising: a substrate and active material layers disposed on two opposing surfaces of the substrate; the battery electrode has a first region and a second region, and the two active material layers have opposing windows at one end of the battery electrode, the first region being the substrate exposed by the windows; the second region being a groove formed by the recess of the battery electrode from one end to the other. By providing opposing windows at one end to expose the substrate to form the first region, and providing recessed grooves to form the second region, multiple technical effects are achieved: the window design of the first region facilitates the welding connection and current conduction of the electrode, improving the conductivity and assembly efficiency of the battery; the groove structure of the second region effectively increases the distance between the positive and negative electrodes, avoiding short circuit problems caused by burrs, deformation, or mechanical stress at the electrode edges.

Description

Technical Field

[0001] This utility model relates to the field of energy storage battery manufacturing technology, and in particular to a battery electrode, a battery cell and a battery. Background Technology

[0002] Lithium-ion batteries mainly consist of four structural components: electrodes, separators, electrolytes, and casings. Electrodes, including positive and negative electrodes, are prepared by coating a substrate surface with a slurry of active materials, conductive agents, dispersants, and binders. The substrate surface can be divided into two areas based on whether or not it is coated with the slurry: the area coated with active materials is the material area, where lithium ions are released and absorbed during battery charging and discharging; the area without active materials is the empty foil area, which is cut into specific shapes and welded together to form tabs, serving a current-conducting function.

[0003] Currently, the tabs are typically located on the top or side of the electrode sheet, forming a "convex" shape, depending on the cell structure. This lead-out tab structure inevitably compresses the internal space of the cell, requiring a certain amount of space to accommodate the tab structure, thus limiting the design space of the material storage area. Taking a 280Ah prismatic cell as an example, the height of the tab after it is inserted into the casing accounts for approximately 3.0% of the height of the material storage area. This space could have provided an 8.4Ah capacity increment, but it is wasted because it needs to accommodate the tab structure. Utility Model Content

[0004] The purpose of this invention is to solve the problem that the space inside the battery cell to accommodate the tab structure is limited in the prior art, resulting in low volumetric energy density of the battery.

[0005] The first aspect of this utility model provides a battery electrode sheet, comprising: a substrate and an active material layer disposed on two opposing surfaces of the substrate;

[0006] The battery electrode has a first region and a second region. The two active material layers have opposing windows at one end of the battery electrode. The first region is the substrate exposed by the window. The second region is a groove formed by the battery electrode recessing from one end to the other.

[0007] Furthermore, the height of the first region is h, h≥10mm; the width is L, L≥20mm.

[0008] A second aspect of this utility model provides a battery cell comprising a plurality of positive electrode plates and a plurality of negative electrode plates, wherein the positive electrode plates and the negative electrode plates are battery electrode plates as described in any of the preceding claims, and the positive electrode plates and the negative electrode plates are alternately arranged.

[0009] Furthermore, the first region of the positive electrode and the second region of the negative electrode are positioned opposite each other; the second region of the positive electrode and the first region of the negative electrode are positioned opposite each other.

[0010] Furthermore, it also includes conductive connecting pieces, including positive conductive pieces and negative conductive pieces;

[0011] The positive electrode conductive sheet is placed in the first region of the positive electrode sheet and is used to connect multiple positive electrode sheets;

[0012] The negative electrode conductive sheet is placed in the first region of the negative electrode sheet and is used to connect multiple negative electrode sheets.

[0013] Furthermore, the positive conductive sheet passes through the second region of the negative conductive sheet; the negative conductive sheet passes through the second region of the positive conductive sheet.

[0014] Furthermore, the height difference between the first region of the positive electrode and the second region of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

[0015] Furthermore, the height difference between the second region of the positive electrode and the first region of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

[0016] Furthermore, the substrate of the positive electrode is aluminum foil, and the substrate of the negative electrode is copper foil.

[0017] The third aspect of this utility model provides a battery cell that uses battery electrodes or battery cells as described in any of the preceding claims.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: by setting a window at one end to expose the substrate to form a first region and setting a recessed groove to form a second region, multiple technical effects are achieved: the window design of the first region facilitates the welding connection of the electrode sheets and current conduction, improving the conductivity and assembly efficiency of the battery; the groove structure of the second region effectively increases the distance between the positive and negative electrode sheets, avoiding short circuit problems caused by burrs, deformation or mechanical stress at the edge of the electrode sheets. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained as provided without creative effort.

[0020] Figure 1This is a front view of a battery electrode sheet in one embodiment of the present invention;

[0021] Figure 2 This is a top view of a battery electrode sheet in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a battery cell in one embodiment of the present invention;

[0023] Wherein, 1-substrate; 2-active material layer; 3-second region; 4-first region; 31-second region of positive electrode; 32-second region of negative electrode; 41-first region of positive electrode; 42-first region of negative electrode. Detailed Implementation

[0024] The following detailed description, with reference to the schematic diagrams, illustrates a battery electrode, battery cell, and battery according to the present invention. Preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being broadly known to those skilled in the art and is not intended to limit the present invention.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0026] The present invention will be described in more detail below by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become clearer as will be explained below. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0027] Example 1

[0028] This embodiment provides a battery electrode sheet; please refer to [reference needed]. Figure 1 and Figure 2 It includes: a substrate 1 and an active material layer 2 disposed on two opposite surfaces of the substrate;

[0029] The battery electrode has a first region 4 and a second region 3. The two active material layers have opposing windows at one end of the battery electrode. The first region 4 is the substrate 1 exposed by the window. The second region 3 is a groove formed by the battery electrode recessed from one end to the other end.

[0030] Specifically, the substrate 1 is typically made of metal foil (such as copper or aluminum foil), serving as the basis for conductivity and load-bearing. The active material layer 2, coated on both sides of the substrate 1, is the actual active material of the battery, responsible for energy storage. The material area is the main area coated with the active material and is also the core working area of ​​the battery, responsible for actual energy storage and release. In this embodiment, the first area 4, the empty foil area, is U-shaped and uncoated with active material. It provides an area for electrode tab welding, serving as a positioning reference for precise alignment during production. The U-shaped structure reduces thickness abrupt changes during electrode winding, lowers stress concentration, and provides natural crease positions for subsequent processing. The second area 3, the cutting area, is a reserved area for subsequent cutting.

[0031] Furthermore, the height of the first region is h, h≥10mm; the width is L, L≥20mm.

[0032] Specifically, the first area sets the height and width dimensions, mainly to ensure the reliability and safety of the electrode connection: a height of not less than 10mm provides sufficient operating space for electrode welding and battery assembly, avoids stress concentration, and ensures welding quality; a width of not less than 20mm ensures sufficient conductive cross-sectional area to meet the conductivity requirements during high-current charging and discharging, prevents increased resistance and localized heating due to insufficient cross-sectional area, and at the same time, a larger contact area also improves the mechanical strength and electrical stability of the connection, and reserves reasonable margins for process tolerances in the manufacturing process.

[0033] The above-described electrode configuration improves production efficiency. Clear area division facilitates automated production, and accurate positioning benchmarks enhance processing precision and product quality. It also reduces damage to the active material during electrode tab welding, lowers internal stress concentration, and improves structural stability. Structural optimization reduces stress damage during use, improving the overall mechanical strength and stability of the battery.

[0034] Example 2

[0035] This embodiment provides a battery cell; please refer to [reference needed]. Figure 3 It includes: multiple positive electrode plates and multiple negative electrode plates, wherein the positive electrode plates and the negative electrode plates are battery electrode plates as described in Embodiment 1, and the positive electrode plates and the negative electrode plates are alternately arranged.

[0036] Furthermore, the first region 41 of the positive electrode and the second region 32 of the negative electrode are positioned opposite each other.

[0037] In this embodiment, the first region 41 of the positive electrode corresponds to the second region 32 of the negative electrode, and the second region 31 of the positive electrode corresponds to the first region 42 of the negative electrode, forming an alternating structural design. By using battery electrodes with a specific structure and alternating the positive and negative electrodes, the internal structure of the cell is optimized. Compared with the prior art, this solution eliminates the need for a traditional "convex" shaped tab structure, avoiding the tab's occupation of internal space in the cell. The alternating arrangement of the positive and negative electrodes ensures the uniformity of current distribution, which is beneficial to improving the battery's charge and discharge performance. This design provides better space utilization, forms a uniform thickness distribution, and effectively reduces local protrusions or depressions; at the same time, by avoiding direct alignment of the positive and negative electrodes, it provides a suitable safe isolation distance, significantly reducing the risk of short circuits and improving the battery's safety performance. In addition, this alternating layout facilitates precise alignment of the electrodes, forming a natural positioning reference, simplifying the assembly process, improving production efficiency, and increasing product yield. In practical applications, this structure can also achieve a more uniform current distribution, ensuring more stable charge and discharge performance, thereby extending the battery's lifespan.

[0038] Furthermore, it also includes conductive connecting pieces, which include positive conductive pieces and negative conductive pieces;

[0039] The positive electrode conductive sheet is placed in the first region 41 of the positive electrode sheet and is used to connect multiple positive electrode sheets;

[0040] The negative electrode conductive sheet is placed in the first region 42 of the negative electrode sheet and is used to connect multiple negative electrode sheets.

[0041] By setting conductive connecting pieces in the first region, reliable series connection between electrodes of the same polarity is achieved, thereby improving the conductivity and structural stability of the battery cell. Specifically, the conductive connecting pieces can be made of materials with good conductivity, such as copper or aluminum, and their shape and size can be adjusted according to actual needs to ensure the welding effect with the electrodes. Welding methods can include laser welding, ultrasonic welding, or resistance welding, which ensure the strength and conductivity of the weld joint.

[0042] By introducing conductive connecting pieces, the problems of weak connections and poor conductivity between electrodes in traditional battery cells are solved. The welding method of the conductive connecting pieces not only improves the connection strength between electrodes but also ensures uniform current distribution, thereby improving the overall performance of the battery. Compared with existing technologies, this solution significantly improves the reliability and lifespan of battery cells through simple structural improvements, while reducing production costs.

[0043] Furthermore, the positive electrode conductive sheet passes through the second region 32 of the negative electrode sheet; the negative electrode conductive sheet passes through the second region 31 of the positive electrode sheet.

[0044] Specifically, the positive electrode conductive sheet can be made of aluminum foil or nickel-plated aluminum strip with a thickness of 0.1-0.3 mm, and is electrically connected to the first region 41 of the positive electrode sheet by laser welding or ultrasonic welding. The negative electrode conductive sheet can be made of copper foil or nickel strip with a thickness of 0.05-0.2 mm, and is connected to the first region 42 of the negative electrode sheet by the same welding process. As a preferred embodiment, an insulating coating can be provided on the surface of the conductive sheet, retaining conductivity only at the contact area with the electrode sheet to prevent short circuits.

[0045] Therefore, this technical solution achieves the following technical effects by placing the conductive connecting piece in the groove structure of the electrode: First, the conductive piece is confined to the second region, avoiding the occupation of the internal space of the battery cell by the traditional tab protrusion structure; second, the positive and negative conductive pieces are arranged alternately in space, making full use of the three-dimensional space of the electrode groove, making the internal structure of the battery cell more compact; finally, since the conductive piece is confined in the groove, it will not be displaced during the winding or stacking of the battery cell, thus avoiding short circuits.

[0046] Furthermore, the height difference between the first region 41 of the positive electrode and the second region 32 of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

[0047] Furthermore, the height difference between the second region 31 of the positive electrode and the first region 42 of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

[0048] Specifically, the positive electrode comprises a first region (h1, L1) and a second region (h2, L2), and the negative electrode comprises a first region (h3, L3) and a second region (h4, L4). In terms of size design, the area of ​​the first region 42 of the negative electrode is smaller than that of the second region 31 of the positive electrode, and the area of ​​the second region 32 of the negative electrode is smaller than that of the first region 41 of the positive electrode. The relationships between these regions satisfy h1-h4≥0.5mm, L1-L4≥0.5mm, h2-h3≥0.5mm, and L2-L3≥0.5mm to prevent lithium-ion deposition.

[0049] Furthermore, the substrate 1 of the positive electrode is aluminum foil, and the substrate 1 of the negative electrode is copper foil.

[0050] The positive electrode uses aluminum foil as substrate 1, and the negative electrode uses copper foil as substrate 1. This material selection is significant: aluminum foil is lightweight, has good conductivity, and is relatively low in cost, and exhibits good chemical stability at the positive electrode operating potential, making it suitable as the positive electrode current collector; copper foil, on the other hand, possesses excellent conductivity, high mechanical strength, and good stability at the negative electrode operating potential, making it ideal as the negative electrode current collector. This choice of substrate 1 not only ensures that the battery has good conductivity and mechanical strength, but also enables it to withstand various stresses during charging and discharging, improving the overall performance and lifespan of the battery. Simultaneously, the differentiated selection of these two materials optimizes the battery's weight and cost, providing a reliable material basis for the large-scale production of the battery.

[0051] Example 3

[0052] This embodiment provides a battery, which is fabricated using the battery electrode sheet described in Embodiment 1 or the battery cell described in Embodiment 2. In this embodiment, the battery can be an alkali metal ion secondary battery, such as a lithium-ion battery or a sodium-ion battery.

[0053] In summary, the battery electrode provided in this application achieves an optimized electrode structure by setting a first region 4 and a second region 3 with a concave structure on the substrate 1, and employing a specific size design and relative positional layout, so that the first region 41 of the positive electrode corresponds to the second region 32 of the negative electrode, and the second region 31 of the positive electrode corresponds to the first region 42 of the negative electrode. This structural design not only ensures reliable welding between the electrode and the connecting piece, but also effectively solves the problem of traditional lead-out electrode structures occupying internal cell space. Simultaneously, by rationally setting the size difference between the positive and negative electrode regions, both processing accuracy and battery safety performance are guaranteed. Furthermore, this structure can also increase the volumetric energy density of the battery, effectively utilize the internal space of the cell, and thus significantly improve battery performance.

[0054] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A battery electrode, characterized in that, include: A substrate and an active material layer disposed on two opposing surfaces of the substrate; The battery electrode has a first region and a second region, and the two active material layers have opposing windows at one end of the battery electrode, wherein the first region is the substrate exposed by the window; The second region is a groove formed by the indentation of the battery electrode from one end to the other.

2. The battery electrode as described in claim 1, characterized in that, The height of the first region is h, h≥10mm; the width is L, L≥20mm.

3. A battery cell, characterized in that, include: Multiple positive electrode plates and multiple negative electrode plates, wherein the positive electrode plates and the negative electrode plates are battery electrode plates as described in any one of claims 1-2, and the positive electrode plates and the negative electrode plates are alternately arranged.

4. The battery cell as described in claim 3, characterized in that, The first region of the positive electrode and the second region of the negative electrode are positioned opposite each other. The second region of the positive electrode is positioned opposite to the first region of the negative electrode.

5. The battery cell as described in claim 4, characterized in that, It also includes conductive connecting pieces, which include a positive conductive piece and a negative conductive piece; The positive electrode conductive sheet is placed in the first region of the positive electrode sheet and is used to connect multiple positive electrode sheets; The negative electrode conductive sheet is placed in the first region of the negative electrode sheet and is used to connect multiple negative electrode sheets.

6. The battery cell as described in claim 5, characterized in that, The positive conductive sheet passes through the second region of the negative electrode sheet; the negative conductive sheet passes through the second region of the positive electrode sheet.

7. The battery cell as described in claim 4, characterized in that, The height difference between the first region of the positive electrode and the second region of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

8. The battery cell as described in claim 4, characterized in that, The height difference between the second region of the positive electrode and the first region of the negative electrode is greater than or equal to 0.5 mm, and the width difference is greater than or equal to 0.5 mm.

9. The battery cell as described in claim 3, characterized in that, The substrate of the positive electrode is aluminum foil, and the substrate of the negative electrode is copper foil.

10. A battery, characterized in that, It is prepared using the battery electrode sheet as described in any one of claims 1-2 or the battery cell as described in any one of claims 3-9.

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