Electrode plate with diversion groove structure and single battery thereof
By setting triangular flow channels on the active material layer of the electrode sheet, the problem of uneven electrolyte distribution after lithium-ion battery injection is solved, thereby improving battery production efficiency and performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2025-07-30
- Publication Date
- 2026-05-19
AI Technical Summary
Existing lithium-ion batteries require a relatively long settling time after electrolyte injection to promote uniform electrolyte distribution, which leads to extended production cycles and affects production efficiency.
Multiple concave flow channels are formed on the active material layer of the electrode sheet. The cross-section of the flow channels is triangular and extends along different directions of the electrode sheet. The spacing and depth of the channels are optimized to promote the uniform distribution of electrolyte.
By utilizing the capillary effect of the flow channel, the wetting performance between the electrode active material and the electrolyte is improved, the battery resting time is shortened, the cell production efficiency and electrochemical performance are enhanced, and the poor film formation consistency and battery cycle instability caused by electrolyte inhomogeneity are avoided.
Smart Images
Figure CN224264061U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery structure technology, specifically to an electrode sheet with a current-guiding groove structure and its single cell battery. Background Technology
[0002] Winded battery cells achieve higher energy density through more efficient placement of active materials, and are therefore widely used in 3C digital products, electric vehicles, energy storage, and military aerospace. Battery cells can include lithium-ion and sodium-ion cells. As the application market continues to expand, the requirements for batteries are also increasing. Taking lithium-ion batteries as an example, to ensure battery performance, the cells need to be left to stand at room temperature or high temperature for a relatively long time after electrolyte filling to promote uniform distribution of the electrolyte inside the cell. However, a longer standing time will extend the production cycle of lithium-ion batteries to some extent.
[0003] Therefore, we continue to provide an electrode sheet with a current-guiding groove structure and its single cell, to further improve the production efficiency and electrochemical performance of the single cell. Summary of the Invention
[0004] To address the problems in related technologies, this utility model proposes an electrode sheet with a flow-guiding groove structure and its single cell, which can effectively promote the electrolyte wetting ability after the cell is injected, shorten the battery aging and standing time, and ultimately improve the cell production efficiency.
[0005] This utility model is implemented as follows:
[0006] An electrode sheet with a flow-guiding groove structure includes a current collector layer and an active material layer; the active material layer is disposed on one or both surfaces of the current collector layer; wherein, the active material layer has multiple concave flow-guiding grooves on the surface opposite to the current collector layer; the cross-section of the flow-guiding groove is triangular; further, the triangle is a right-angled triangle, an isosceles triangle, or a scalene triangle. Among them, the right-angled triangle has the best application effect. Further, when a right-angled triangle is used, the bottom angle of the flow-guiding groove is 45°.
[0007] The flow guide groove extends along the length direction of the electrode sheet;
[0008] Alternatively, the flow guide groove may extend along the width direction of the electrode sheet;
[0009] Alternatively, the flow channel may be provided by extending obliquely along the width direction of the electrode sheet;
[0010] Or multiple of the aforementioned guide channels may be simultaneously extended in any of the aforementioned directions.
[0011] This invention, by setting a flow channel on the active material layer, can promote the absorption of electrolyte inside the electrode, improve the wetting performance of the electrode active material and the electrolyte, and reduce the unevenness of electrolyte distribution. In particular, the cross-section of the flow channel is triangular, and the resulting triangular prism-like structure has a small inscribed radius, which can enhance the capillary effect and, correspondingly, effectively enhance the ability to absorb liquid and wet the electrode.
[0012] As a further optimization of the above scheme, let the thickness of the active material layer be denoted as d, the depth of the flow channel be denoted as h, and the radial dimension of the flow channel be denoted as i. Then, 5um≤h≤1 / 2d and 5um≤i≤10mm.
[0013] As a further optimization of the above solution, when the guide groove extends along the width direction of the electrode sheet, the multiple guide grooves are evenly spaced along the length direction of the electrode sheet.
[0014] The length of the electrode plate is denoted as L, and the interval between two adjacent flow channels is m. Then 10 ≤ L / m ≤ 1000.
[0015] As a further optimization of the above solution, when the guide groove extends along the length direction of the electrode sheet, the multiple guide grooves are evenly spaced along the width direction of the electrode sheet.
[0016] The length of the electrode plate is denoted as w, and the interval between two adjacent flow channels is denoted as x. Then 0 ≤ w / x ≤ 100.
[0017] As a further optimization of the above scheme, when the flow guide groove extends along the length direction of the electrode sheet, the plurality of flow guide grooves are centrally located along the width direction of the electrode sheet.
[0018] At this point, the spacing between any two adjacent guide channels can be set to be either equal or unequal.
[0019] This utility model also provides a single battery cell, including a positive electrode and a negative electrode. The positive electrode and / or the negative electrode are made of an electrode with a current-guiding groove structure as described above; the positive electrode and the negative electrode are wound to form a square cell or a cylindrical cell;
[0020] When both the positive electrode and the negative electrode are provided with a flow channel, the flow channel of one electrode faces the other electrode, and the flow channels of the two electrodes are opposite to each other or staggered. This can further improve the absorption capacity of the electrode to the electrolyte and promote the wettability of the active material to the electrolyte. The effect is best when the flow channels are opposite to each other.
[0021] The single cell also includes a separator membrane, which is disposed between the positive electrode and the negative electrode, and the flow channel faces the separator membrane.
[0022] For cylindrical cells, the electrode plates are located in the central region of the width direction, which is far from the sides. The electrolyte wetting is slowest, which can easily lead to lithium plating.
[0023] Therefore, setting a guide groove extending along the length direction in the center of the width direction of the electrode sheet can effectively improve the electrolyte flow capacity in the middle of the electrode sheet, avoid uneven electrolyte due to slow liquid absorption, and prevent problems such as poor film formation consistency, battery capacity and cycle instability.
[0024] As a further optimization of the above solution, the electrode sheet is bent multiple times to form the square battery cell; wherein, the electrode sheet is provided with one or more flow guide grooves at the bending points.
[0025] At this point, the spacing between adjacent guide channels is not fixed. The closer to the center of the cell, the smaller the spacing between adjacent guide channels; the farther away from the center of the cell, the larger the spacing between adjacent guide channels.
[0026] Because the stacking pressure on the cell at the fold is relatively greater than other locations, the electrolyte is difficult to wet. Setting a flow channel at this location can reduce the areal density, effectively disperse the pressure, improve the wettability of the electrode active material with the electrolyte, promote ion transport, and suppress phenomena such as poor ion intercalation and negative electrode metal deposition.
[0027] As a further optimization of the above solution, when the single battery cell adopts a square cell, some or all of the current guiding grooves are extended along the width direction of the electrode plates.
[0028] The depth of the guide groove is the greatest near the center of the square battery cell, and the depth of the guide groove is the smallest away from the center of the square battery cell, with the depth of the guide groove gradually changing in the middle.
[0029] For square cells, the stacking pressure at the fold is relatively greater than at other locations. Due to the curvature, the pressure is greater closer to the inner layer of the cell, making it more difficult for the electrolyte to wet. Setting a deeper channel at this location can further reduce the areal density, disperse the pressure on the electrode, and further improve the wettability of the electrode active material with the electrolyte, promote ion transport, and suppress phenomena such as poor ion intercalation and negative electrode metal deposition.
[0030] As a further optimization of the above scheme, if the single cell is a lithium-ion battery, then the active material layer in the positive electrode sheet is one or more of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium iron manganese phosphate, and NCM ternary positive electrode materials; NCM is a lithium-ion battery positive electrode material composed of three metal elements: nickel (Ni), cobalt (Co), and manganese (Mn). Their proportions can be adjusted according to different application requirements;
[0031] In the negative electrode sheet, the active material layer is made of one or more of the following materials: lithium metal, artificial graphite, natural graphite, hard carbon, silicon-carbon negative electrode material, tin-based negative electrode material, and lithium titanate.
[0032] As a further optimization of the above scheme, if the single cell is a sodium-ion battery, then the active material layer in the positive electrode sheet is made of Na. x MO2, where x≤1, and M is one or more of K, Li, Mg, Ti, V, Cr, Mn, Fe, Co, Ni and Cu;
[0033] In the negative electrode sheet, the active material layer is made of one or more of graphite, hard carbon, and metal oxides. That is, the negative electrode material uses a material that has sodium intercalation and sodium storage capabilities.
[0034] The beneficial effects are as follows:
[0035] (1) This utility model provides an electrode sheet with a flow-guiding groove structure and its single battery. By setting the flow-guiding groove on the active material layer, the electrode sheet is quickly wetted by the capillary effect of the flow-guiding groove, which can promote the absorption of electrolyte inside the electrode sheet, improve the wetting performance of the electrode active material and the electrolyte, reduce the uneven distribution of electrolyte, and effectively reduce the battery standing formation time.
[0036] (2) For cylindrical cells, a guide groove extending along the length direction is set in the center of the width direction of the electrode sheet, which can effectively improve the electrolyte flow capacity in the middle of the electrode sheet and avoid uneven electrolyte due to slow liquid absorption, which in turn leads to poor consistency of subsequent formation film, battery capacity and cycle instability.
[0037] (3) For square cells, different spacing and depth of guide grooves are set on the electrode plates according to the distance from the center of the cell. This can reduce the surface density of the electrode plates at the bending point, disperse the pressure, improve the wettability of the electrode active material and the electrolyte at that point, promote ion transport, and also suppress the occurrence of phenomena such as poor ion intercalation and negative electrode metal deposition. Attached Figure Description
[0038] Figure 1 This is a top view of the electrode sheet provided in Embodiment 1 of this utility model;
[0039] Figure 2 A side view of the electrode sheet provided in Embodiment 1 of this utility model;
[0040] Figure 3 This is a side view of the electrode sheet provided in Embodiment 2 of this utility model;
[0041] Figure 4 A side view of the electrode sheet provided in Embodiment 3 of this utility model;
[0042] Figure 5 This is a schematic diagram of the structure of the electrode sheet provided in Embodiment 4 of this utility model;
[0043] Figure 6 A schematic diagram of the winding of a square battery cell provided in Embodiment 5 of this utility model;
[0044] Figure 7 A schematic diagram showing the distribution of the flow channels in the electrode sheet provided in Embodiment 5 of this utility model;
[0045] Figure 8 A side view of the electrode sheet provided in Embodiment 6 of this utility model;
[0046] Figure label:
[0047] 101. Current collector layer;
[0048] 102. Active substance layer;
[0049] 103. Flow guide channel. Detailed Implementation
[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0051] Example 1
[0052] like Figure 1 , 2 As shown, this embodiment provides a single-cell battery, including a positive electrode and a negative electrode. The positive electrode uses the following electrode structure:
[0053] An electrode sheet with a flow-guiding groove structure includes a current collector layer 101 and an active material layer 102; the active material layer 102 is disposed on one surface of the current collector layer 101; wherein, the active material layer 102 has a plurality of concave flow-guiding grooves 103 on the surface of the active material layer 102 facing away from the current collector layer 101. The cross-section of the flow-guiding grooves 103 is triangular, specifically an isosceles triangle. Ultimately, the structure of the flow-guiding grooves 103 forms a quasi-triangular prism structure.
[0054] In this embodiment, the length of the electrode sheet is denoted as L, the width as w, the thickness of the active material layer 102 as d, the depth of the guide groove 103 as h, the radial dimension of the guide groove 103 as i, and the interval between two adjacent guide grooves 103 as m; then 5um≤h≤1 / 2d, 5um≤i≤10mm, and 10≤L / m≤1000 are satisfied.
[0055] In this embodiment, the guide groove 103 extends along the width direction of the electrode sheet, that is, the length of the guide groove 103 is equal to the width w of the electrode sheet, and the guide groove 103 is parallel to the wide side of the electrode sheet; at this time, multiple guide grooves 103 are evenly distributed along the length direction of the electrode sheet, with an interval of m.
[0056] This invention, by providing a flow channel 103 on the active material layer 102, can promote the absorption of electrolyte inside the electrode, improve the wetting performance between the electrode active material and the electrolyte, and reduce the unevenness of electrolyte distribution. In particular, the cross-section of the flow channel 103 is triangular, and the resulting triangular prism-like structure has a small inscribed radius, which can enhance the capillary effect and, correspondingly, effectively strengthen the ability to absorb liquid and wet the electrode.
[0057] The positive and negative electrode sheets are wound together to form a battery cell. After winding, there is a separator between the positive and negative electrode sheets, and the current guide groove 103 faces the separator.
[0058] In this embodiment, the single battery cell is a lithium-ion battery.
[0059] In this embodiment, the active material layer 102 of the positive electrode is made of lithium iron phosphate, and the current collector layer 101 is made of aluminum foil. In other embodiments, the current collector layer 101 may also be made of other materials, but aluminum foil is the most effective.
[0060] In this embodiment, the active material layer 102 of the negative electrode sheet is made of graphite, and the current collector layer 101 is made of copper foil. In other embodiments, the current collector layer 101 may also be made of other materials, but copper foil is the most effective.
[0061] In this embodiment, the electrode channel 103 is provided on the positive electrode sheet, and the negative electrode surface density margin at the corresponding position is increased, which reduces the number of ions that migrate in the positive electrode active layer. It can also reduce the local metal precipitation phenomenon inside the battery, reduce the battery safety hazards, and improve electrochemical performance.
[0062] Example 2
[0063] This implementation example Figure 3 As shown, features not explained in this embodiment are explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:
[0064] The flow channel 103 is obliquely extended based on the width direction of the electrode sheet, that is, the flow channel 103 forms an oblique line relative to the wide side of the electrode sheet, and the length of the flow channel 103 is greater than the width w of the electrode sheet.
[0065] Example 3
[0066] This implementation example Figure 4 As shown, features not explained in this embodiment are explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:
[0067] The cross-section of the guide channel 103 is triangular, specifically a right triangle, and the bottom angle of the guide channel 103 is 45°.
[0068] Example 4
[0069] This implementation example Figure 5 As shown, features not explained in this embodiment are explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:
[0070] The single battery cell in this embodiment uses a cylindrical cell.
[0071] On the active material layer 102, the flow channel 103 extends both along the length direction of the electrode sheet and along the width direction of the electrode sheet, and the two types of flow channels 103 intersect each other.
[0072] That is, the length of part of the guide groove 103 is the same as the length L of the electrode plate, and is parallel to the long side of the electrode plate; in the current part of the guide groove 103, the interval between adjacent guide grooves 103 is denoted as x, which satisfies 0≤w / x≤100.
[0073] The length of part of the guide groove 103 is the same as the width w of the electrode sheet and is parallel to the wide side of the electrode sheet. For cylindrical cells, the electrode sheet is farther from the sides in the central region in the width direction, where electrolyte wetting is slowest and lithium plating is more likely to occur.
[0074] Therefore, the flow channel 103, which is centrally located in the width direction of the electrode sheet and extends along the length direction, can effectively improve the electrolyte flow capacity in the middle of the electrode sheet, avoid uneven electrolyte due to slow liquid absorption, and prevent subsequent formation film uniformity, battery capacity and cycle instability.
[0075] Example 5
[0076] This implementation example Figure 6 , 7 As shown, features not explained in this embodiment are explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:
[0077] The single battery cell in this embodiment uses a square cell.
[0078] All the guide grooves 103 extend along the width direction of the electrode sheet. After winding, it can be seen that each guide groove 103 is located at the bend of the electrode sheet. At this time, the interval between adjacent guide grooves 103 is not fixed. The closer to the center of the cell, the smaller the interval between adjacent guide grooves 103; the farther away from the center of the cell, the larger the interval between adjacent guide grooves 103. If the guide grooves 103 are denoted as a, b to f, then the interval of ab is smaller than the interval of bc, the interval of bc is smaller than the interval of cd, and so on.
[0079] In this embodiment, the depth of the guide groove 103 near the center of the square battery cell is the greatest, and the depth of the guide groove 103 farther from the center of the square battery cell is the smallest, with the depth of the guide groove 103 in the middle gradually changing. That is, the depth of a is greater than b, b is greater than c, and so on.
[0080] Because the stacking pressure on the cell at the fold is relatively greater than other locations, and because of the curvature, the closer to the inner layer of the cell, the more difficult it is for the electrolyte to wet. Setting a deeper channel 103 at the fold can reduce the areal density at that location, effectively disperse the pressure, improve the wettability of the electrode active material and the electrolyte, promote ion transport, and also suppress phenomena such as poor ion intercalation and negative electrode metal deposition.
[0081] Example 6
[0082] This implementation example Figure 8 As shown, features not explained in this embodiment are explained using the method described in Embodiment 5, and will not be repeated here. The difference between this embodiment and Embodiment 5 is as follows:
[0083] The electrode sheet has two guide grooves 103 at the bending point.
[0084] Example 7
[0085] Features not explained in this embodiment are explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:
[0086] Both the positive and negative electrode plates are electrode plates with a current-guiding groove structure.
[0087] After winding, the guide groove 103 of one electrode faces the other electrode, and the guide grooves 103 of the two electrodes are opposite each other, which can further improve the absorption capacity of the electrode to the electrolyte and promote the wettability of the active material to the electrolyte.
[0088] For electrode plates, the greater the width and depth of the flow channel 103, the greater the capacity loss. Here, capacity refers to the capacity for charge.
[0089] At this time, the guide groove 103 (width / depth) of the positive electrode is larger than that of the negative electrode, that is, the loss capacity value of the former is greater than that of the latter.
[0090] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.
Claims
1. An electrode sheet with a flow-guiding groove structure, characterized in that, It includes a current collector layer and an active material layer; the active material layer is disposed on one or two surfaces of the current collector layer; wherein, the active material layer has a plurality of concave guide grooves on the surface opposite to the current collector layer; the cross-section of the guide grooves is triangular; The flow guide groove extends along the length direction of the electrode sheet; Alternatively, the flow guide groove may extend along the width direction of the electrode sheet; Alternatively, the flow channel may be provided by extending obliquely along the width direction of the electrode sheet; Or multiple of the aforementioned guide channels may be simultaneously extended in any of the aforementioned directions.
2. The electrode sheet with a flow-guiding groove structure according to claim 1, characterized in that: Let the thickness of the active material layer be denoted as d, the depth of the flow channel be denoted as h, and the radial dimension of the flow channel be denoted as i. Then, 5um≤h≤1 / 2d and 5um≤i≤10mm.
3. The electrode sheet with a flow-guiding groove structure according to claim 1, characterized in that: When the flow guide groove extends along the width direction of the electrode sheet, the plurality of flow guide grooves are evenly spaced along the length direction of the electrode sheet; The length of the electrode plate is denoted as L, and the interval between two adjacent flow channels is m. Then 10 ≤ L / m ≤ 1000.
4. The electrode sheet with a flow-guiding groove structure according to claim 1, characterized in that: When the guide groove extends along the length direction of the electrode sheet, the multiple guide grooves are evenly spaced along the width direction of the electrode sheet. The width of the electrode plate is denoted as w, and the interval between two adjacent flow channels is denoted as x. Then 0 ≤ w / x ≤ 100.
5. An electrode sheet with a flow-guiding groove structure according to claim 1, characterized in that: When the guide groove extends along the length direction of the electrode sheet, the plurality of guide grooves are centrally located along the width direction of the electrode sheet.
6. A single-cell battery, comprising a positive electrode and a negative electrode; characterized in that: The positive electrode and / or the negative electrode are made of an electrode with a current-guiding groove structure as described in any one of claims 1 to 5; the positive electrode and the negative electrode are wound to form a square cell or a cylindrical cell; When both the positive electrode and the negative electrode are provided with flow guide grooves, the flow guide groove of one electrode faces the other electrode, and the flow guide grooves of the two electrodes are opposite to each other or staggered. The single cell also includes a separator membrane, which is disposed between the positive electrode and the negative electrode, and the flow channel faces the separator membrane.
7. A single-cell battery according to claim 6, characterized in that: The electrode sheet is bent multiple times to form the square battery cell; wherein, the electrode sheet has one or more flow guide grooves at the bending points.
8. A single-cell battery according to claim 6, characterized in that: When the single battery cell adopts a square cell, some or all of the current guiding grooves are extended along the width direction of the electrode plate; The depth of the guide groove is the greatest near the center of the square battery cell, and the depth of the guide groove is the smallest away from the center of the square battery cell, with the depth of the guide groove gradually changing in the middle.
9. A single-cell battery according to claim 6, characterized in that: If the single cell is a lithium-ion battery, then the active material layer in the positive electrode sheet is one or more of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium iron manganese phosphate, and NCM ternary positive electrode materials. In the negative electrode sheet, the active material layer is made of one or more of the following materials: lithium metal, artificial graphite, natural graphite, hard carbon, silicon-carbon negative electrode material, tin-based negative electrode material, and lithium titanate.
10. A single-cell battery according to claim 6, characterized in that: If the single cell is a sodium-ion battery, then the active material layer in the positive electrode is made of Na. x MO2, where x≤1, and M is one or more of K, Li, Mg, Ti, V, Cr, Mn, Fe, Co, Ni and Cu; In the negative electrode sheet, the active material layer is made of one or more of the following materials: graphite, hard carbon, and metal oxides.