Battery structure, battery assembly and coating method
By differentiating the flow rate of reactive gases and the thin film deposition method, the problem of uneven passivation layer thickness in traditional coating processes was solved, and the smoothness and passivation effect of the passivation layer on the cut surface of the battery cell were improved.
Patent Information
- Application Number
- CN202510397728.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-11-29
- Filing Date
- 2025-03-28
- Publication Date
- 2025-12-12
AI Technical Summary
Traditional coating processes cannot form passivation layers of varying thicknesses at different cut surfaces of the solar cell, resulting in poor passivation layer smoothness and passivation effect, especially at the laser-cut surfaces near the guide lines.
By controlling the flow rate of the reactive gas during the coating process, the flow rate to the laser-cut surface is made greater than that to the stress-cut surface. A differentially controlled thin film deposition method is used to form a first passivation layer with a thickness greater than that to the stress-cut surface on the laser-cut surface, ensuring that the outer surface of the passivation layer is on the same horizontal plane.
It improves the smoothness and passivation effect of the passivation layer on the cut surface, thereby enhancing the passivation effect of the battery cell.
Smart Images
Figure CN121126969A_ABST
Abstract
Description
[0001] This application claims priority to Chinese Patent Application No. 202411746513.7, filed on November 29, 2024, entitled "A Coating Equipment and Coating Method", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of coating technology, and in particular to a battery structure, battery assembly and coating method. Background Technology
[0003] The solar cells cut by laser non-destructive cutting are grooved at both ends (guide lines), and then split in two at the middle using a combination of thermal and mechanical stress, thus achieving the slicing effect. Because the guide lines require laser grooving, the morphology of the cut surface at this location differs from other locations: taking a 146μm thick silicon wafer as an example, the laser-cut surface 21 formed by laser tail damage reaches a thickness of 94μm; this area has a lower height and a rougher cut surface; for example... Figure 1 As shown, the stress-cut surface 22 in the middle of the cut surface is stress-treated instead of laser-treated, so the cut surface in this area is relatively smooth; as Figure 2 As shown, the intermediate stress-cutting surface 22 and the two laser-cutting surfaces 21 form a height difference of approximately 7 μm, resulting in poor surface smoothness. However, traditional coating processes cannot achieve passivation layers of different thicknesses at different locations on the cut surfaces, leading to poor passivation layer smoothness and consequently, poor passivation effect at the guide line location. Summary of the Invention
[0004] The purpose of this application is to provide a battery structure, battery assembly, and coating method, which can improve the flatness of the passivation layer on the cut surface, thereby improving the passivation effect of the cut surface.
[0005] To achieve the above objectives, this application provides a battery structure, comprising: a battery cell; the battery cell having at least one cut surface; the cut surface having a first passivation layer; the cut surface including a laser-cut surface and a stress-cut surface; in the length direction of the cut surface, the laser-cut surface is located at both ends of the cut surface, and the stress-cut surface is located between the two laser-cut surfaces; the thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the first passivation layer located on the stress-cut surface; the thickness difference between the first passivation layer located on the laser-cut surface and the first passivation layer located on the stress-cut surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
[0006] Optionally, the first passivation layer includes a SiO2 layer and an AlO layer. xAny one of the following: a layer, a gallium oxide layer, or a zirconium oxide layer;
[0007] And / or, the average thickness of the first passivation layer is 30nm-100nm, including the values at both ends.
[0008] Optionally, the two ends where the battery cell intersects with the cut surface are the first non-cut surfaces, and the first passivation layer is deposited around the two first non-cut surfaces on the battery cell; in the length direction of the first non-cut surfaces, the length of the first passivation layer deposited around the first non-cut surfaces is not greater than 10mm.
[0009] Optionally, a hydrogen-rich AlO2 layer is disposed on the surface opposite to the first passivation layer. x Layer, hydrogen-rich SIN x Layer, hydrogen-rich SiO x Layer, hydrogen-rich silicon oxynitride, hydrogen-rich SiO x N y Layer or hydrogen-rich AlN x Any of the layers.
[0010] Optionally, the side surface of the battery cell opposite to the cut surface is a second non-cut surface; the second non-cut surface is provided with a second passivation layer; the thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the second passivation layer.
[0011] Optionally, the second passivation layer includes an aluminum oxide layer and a silicon nitride layer stacked together; the thickness of the aluminum oxide layer is 4nm-8nm, including the values at both ends; the thickness of the silicon nitride layer is 70nm-90nm, including the values at both ends.
[0012] Optionally, the second passivation layer further includes any one or more of a silicon nitride layer, a silicon oxynitride layer, or a silicon oxide layer.
[0013] To achieve the above objectives, this application also provides a battery assembly, including the battery structure described above.
[0014] To achieve the above objectives, this application provides a coating method, comprising:
[0015] The battery cell is placed inside the reaction chamber with its cut surface facing the air inlet of the reaction chamber; the cut surface includes a laser-cut surface and a stress-cut surface; along the length of the cut surface, the laser-cut surface is located at both ends of the cut surface, and the stress-cut surface is located between the two laser-cut surfaces;
[0016] The reactive gas is introduced into the interior of the reaction chamber through the gas inlet, and the flow rate of the reactive gas is controlled by a gas flow control device, so that the flow rate of the reactive gas flowing towards the laser cutting surface is greater than the flow rate of the reactive gas flowing towards the stress cutting surface; the gas flow control device is located on the flow path of the reactive gas.
[0017] Thin film deposition is performed based on the reactive gas to form a first passivation layer on the cutting surface; the thickness of the first passivation layer on the laser cutting surface is greater than the thickness of the first passivation layer on the stress cutting surface; the thickness difference between the first passivation layer on the laser cutting surface and the first passivation layer on the stress cutting surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
[0018] Optionally, the thin film deposition based on the reactive gas to form a first passivation layer on the cut surface includes:
[0019] The turntable at the bottom of the reaction chamber drives the battery cell to rotate in the circumferential direction, so that the reaction gas and the isolation gas flow alternately to the battery cell, and the first thin film deposition is performed based on the reaction gas to form the first passivation layer on the laser-cut surface.
[0020] After the first passivation layer is formed, the first cover plate is removed;
[0021] After removing the first cover plate, a second thin film deposition is performed based on the reactive gas to form a second layer of the first passivation layer on the laser-cut surface and the stress-cut surface. This application provides a battery structure comprising: a battery cell; the battery cell having at least one cut surface; a first passivation layer disposed on the cut surface; the cut surface including a laser-cut surface and a stress-cut surface; in the length direction of the cut surface, the laser-cut surface is located at both ends of the cut surface, and the stress-cut surface is located between the two laser-cut surfaces; the thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the first passivation layer located on the stress-cut surface; the thickness difference between the first passivation layer located on the laser-cut surface and the first passivation layer located on the stress-cut surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
[0022] Obviously, this application, by differentially controlling the thickness of the first passivation layer on the laser-cut surface and the stress-cut surface, ensures that the thickness of the first passivation layer deposited on the laser-cut surface can be greater than that deposited on the stress-cut surface, thereby improving the flatness of the first passivation layer on the cut surface and thus improving the passivation effect of the cut surface. This application also provides a battery assembly with the above-mentioned beneficial effects. This application also provides a coating method, which uses a reactive gas spray coating method. A gas flow control device is set in the flow path of the reactive gas. The flow rate of the reactive gas is controlled by the gas flow control device so that the flow rate of the reactive gas flowing to the laser-cut surface is greater than that flowing to the stress-cut surface. This achieves differential control of the thickness of the first passivation layer deposited on the laser-cut surface and the stress-cut surface, ensuring that the thickness of the first passivation layer deposited on the laser-cut surface can be greater than that deposited on the stress-cut surface, thereby improving the flatness of the passivation layer on the cut surface and thus improving the passivation effect of the cut surface. Attached Figure Description
[0023] 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the stress-cut surface.
[0025] Figure 2 This is a schematic diagram of the cut surface;
[0026] Figure 3 A cross-sectional view of a battery cell along a direction perpendicular to the cutting surface, provided for an embodiment of this application;
[0027] Figure 4 A flowchart of a coating method provided in an embodiment of this application;
[0028] Figure 5 This is a schematic diagram of the structure of the first coating device provided in the embodiments of this application;
[0029] Figure 6 This is a schematic diagram of the structure of the second coating device provided in the embodiments of this application;
[0030] Figure 7 This is a schematic diagram of the structure of a third coating device provided in an embodiment of this application.
[0031] The annotations in the attached figures are explained as follows:
[0032] 1-Reaction chamber; 11-Gas outlet; 2-Battery cell; 21-Laser-cut surface; 22-Stress-cut surface; 23-First passivation layer; 3-Flow equalization plate; 31-Gas inlet; 41-First cover plate; 42-Second cover plate; 43-Third cover plate; 431-Flow guide hole; 5-Material box; 61-Reaction gas; 62-Isolation gas. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0034] Please refer to Figure 3 , Figure 3 This application provides a cross-sectional view of a battery cell along a direction perpendicular to the cut surface. The battery structure provided in this application includes: a battery cell 2; the battery cell 2 has at least one cut surface; a first passivation layer 23 is disposed on the cut surface; the cut surface includes a laser-cut surface 21 and a stress-cut surface 22; in the length direction of the cut surface, the laser-cut surface 21 is located at both ends of the cut surface, and the stress-cut surface 22 is located between the two laser-cut surfaces 21; the thickness of the first passivation layer 23 located on the laser-cut surface 21 is greater than the thickness of the first passivation layer 23 located on the stress-cut surface 22; the thickness difference between the first passivation layer 23 located on the laser-cut surface 21 and the first passivation layer 23 located on the stress-cut surface 22 is greater than 10 nm, and the outer surface of the first passivation layer 23 is on the same horizontal plane.
[0035] This embodiment does not limit the specific type of solar cell 2. Solar cell 2 can be, but is not limited to, a silicon wafer.
[0036] This embodiment does not limit the specific type of the first passivation layer 23. For example, the first passivation layer 23 may include a SiO2 layer, AlO2 layer, etc. x The first passivation layer 23 may be any one of a gallium oxide layer or a zirconium oxide layer; furthermore, a hydrogen-rich AlO2 layer may be disposed on the surface opposite to the first passivation layer 23. x Layer, hydrogen-rich SIN x Layer, hydrogen-rich SiO x Layer, hydrogen-rich silicon oxynitride, hydrogen-rich SiO x N y Layer or hydrogen-rich AlN x Any of the layers. It should be noted that "hydrogen-rich" refers to a layer containing a high concentration of hydrogen atoms; all of the above passivation layers are hydrogen passivation layers. The latter uses a stacked passivation layer structure, resulting in better passivation.
[0037] This embodiment does not limit the specific thickness of the first passivation layer 23. For example, the average thickness of the first passivation layer 23 can be 30nm-100nm, including the values at both ends. It should be noted that the thickness of the first passivation layer 23 affects the passivation effect. In this embodiment, the average thickness of the first passivation layer 23 is within the above range, resulting in a better passivation effect.
[0038] It should be noted that during the process of forming the first passivation layer 23 on the cut surface, the first passivation layer 23 can easily be deposited around to other surfaces adjacent to the cut surface. In this embodiment, the two ends where the battery cell 2 intersects with the cut surface are the first non-cut surfaces, and the first passivation layer 23 is deposited around to the two first non-cut surfaces on the battery cell 2; in the length direction of the first non-cut surface, the length of the first passivation layer 23 deposited around the first non-cut surface can be no more than 10 mm.
[0039] In this embodiment, the surface of the battery cell 2 opposite to the cut surface can be a second non-cut surface; a second passivation layer is provided on the second non-cut surface; the thickness of the first passivation layer 23 located on the laser-cut surface 21 can be greater than the thickness of the second passivation layer. It should be noted that in this embodiment, providing a second passivation layer on the second non-cut surface can provide passivation for the second non-cut surface. The greater thickness of the first passivation layer 23 on the laser-cut surface 21 compared to the second passivation layer can improve the passivation effect of the laser-cut surface 21.
[0040] This embodiment does not limit the specific type of the second passivation layer. For example, the second passivation layer may include a stacked aluminum oxide layer and a silicon nitride layer; the thickness of the aluminum oxide layer may be 4nm-8nm, including both ends; the thickness of the silicon nitride layer may be 70nm-90nm, including both ends; furthermore, the second passivation layer may also include any one or more of a silicon nitride layer, a silicon oxynitride layer, or a silicon oxide layer. It should be noted that the above passivation layers all belong to field passivation layers. The latter adopts a stacked passivation layer structure, which has a better passivation effect.
[0041] Furthermore, it should be noted that when the passivation layer of the cut surface uses the aforementioned hydrogen passivation layer and the second non-cut surface uses the aforementioned field passivation layer, some hydrogen in the hydrogen passivation layer will enter the field passivation layer during the preparation process, forming a mixed layer between the hydrogen passivation layer and the field passivation layer. This is a reasonable layer formed due to process reasons.
[0042] Based on the above embodiments, this application ensures that the thickness of the first passivation layer deposited on the laser-cut surface and the stress-cut surface can be greater than the thickness of the first passivation layer deposited on the stress-cut surface by differentially controlling the thickness of the first passivation layer, thereby improving the flatness of the passivation layer on the cutting surface and thus improving the passivation effect of the cutting surface.
[0043] This application provides a battery assembly, including the battery structure described above.
[0044] Based on the above embodiments, this application adopts the above-described battery structure, which also has the above-described beneficial effects.
[0045] Traditional coating processes cannot achieve passivation layers of different thicknesses on cut surfaces at different locations, resulting in poor flatness of the passivation layer and poor passivation effect on laser-cut surfaces.
[0046] Please refer to Figure 4 , Figure 4 A flowchart of a coating method provided in this application embodiment, the method may include:
[0047] S101: Place the battery cell inside the reaction chamber with the cut surface of the battery cell facing the air inlet of the reaction chamber; the cut surface includes a laser cut surface and a stress cut surface; in the length direction of the cut surface, the laser cut surface is located at both ends of the cut surface, and the stress cut surface is located between the two laser cut surfaces.
[0048] Furthermore, in order to improve the coating efficiency, step S101 in this embodiment may include:
[0049] The battery cells 2 are stacked in the material box 5 along the thickness direction;
[0050] After placement, place the material box 5 inside the reaction chamber 1, so that the cut surface of each battery cell 2 faces the air inlet of the reaction chamber 1.
[0051] S102: The reaction gas enters the interior of the reaction chamber through the gas inlet, and the flow rate of the reaction gas is controlled by the gas flow control device so that the flow rate of the reaction gas flowing to the laser cutting surface is greater than the flow rate of the reaction gas flowing to the stress cutting surface; the gas flow control device is set on the flow path of the reaction gas.
[0052] This embodiment does not limit the specific structure of the gas flow control device, for example:
[0053] The gas flow control device may include a flow equalizer 3; the flow equalizer 3 is provided with an array of air inlets 31 and is located at the air inlet end;
[0054] The flow equalizer 3 includes two reaction gas 61 inlet zones and two isolation gas 62 inlet zones arranged alternately along the circumferential direction; the two reaction gas 61 inlet zones are used to introduce different reaction gases 61; the isolation gas 62 inlet zones are used to introduce isolation gases 62.
[0055] The turntable at the bottom of the reaction chamber 1 is used to drive the battery cell 2 to rotate in the circumferential direction, so that the gas inlet area of the reaction gas 61 and the gas inlet area of the isolation gas 62 alternately correspond to the battery cell 2.
[0056] It should be noted that in this embodiment, the flow equalization plate 3 is set at the air inlet end to split the reaction gas 61 and the isolation gas 62 that are directed to the air inlet end.
[0057] In this embodiment, the specific type of reactant gas 61 used can be determined according to the specific type of the first passivation layer. When only one type of reactant gas 61 is used, the flow equalization plate 3 does not need to be divided. When two types of reactant gas 61 are used, the flow equalization plate can be divided to insert an isolation gas 62 inlet area between the two reactant gas 61 inlet areas, thereby isolating the reactant gas 61 through the isolation gas 62. When multiple types of reactant gas 61 are used, the same principle applies as when two types of reactant gas 61 are used, and will not be elaborated here.
[0058] In this embodiment, the specific types of the reactant gas 61 and the isolation gas 62 can be determined based on the specific type of the first passivation layer. For example, the first passivation layer may include AlO. x In this layer, the two reacting gases 61 can be TMA (Trimethylaluminum Alumina) and water, respectively; the isolating gas 62 can be nitrogen. Both TMA and water are specialty gases.
[0059] It should be noted that the inlet area of the reaction gas 61 and the inlet area of the isolation gas 62 are alternately connected to the battery cell 2, which allows the reaction gas 61 and the isolation gas 62 to flow alternately to the battery cell 2.
[0060] This embodiment does not limit the specific arrangement of the air inlets 31 in the flow equalization plate, as long as it can ensure the separation of the reactant gas 61 and the isolation gas 62. For example, the flow equalization plate 3 can be provided with air inlets 31 arranged in a circular array, and the air inlets 31 in each reactant gas 61 inlet area and each isolation gas 62 inlet area are arranged in a fan-shaped array; the arrangement direction of the laser cutting surface 21 and the stress cutting surface 22 is parallel to the radial direction of the fan-shaped array. It should be noted that in this embodiment, the two laser cutting surfaces 21 are located on the side closer to the center of the circular array and the side away from the center of the circular array, respectively, and the stress cutting surface 22 is located on the two laser cutting surfaces 21.
[0061] The gas flow control device used in this embodiment is different, and correspondingly, the method of controlling the flow rate of the reactant gas 61 is also different. This embodiment does not limit the specific method of controlling the flow rate of the reactant gas 61; for example, the following three methods can be used:
[0062] (1) Please refer to Figure 5The gas flow control device may also include a first cover plate 41; the first cover plate 41 is disposed at a position corresponding to the stress cutting surface 22 and is connected in a movable manner; the size of the first cover plate 41 is greater than or equal to the size of the stress cutting surface 22. This structure achieves selective passivation of the laser cutting surfaces 21 on both sides by adding a first cover plate 41 at the position corresponding to the stress cutting surface 22, and requires two passivation processes to achieve the purpose of selective passivation.
[0063] This embodiment only limits the width of the first cover plate 41. The width of the first cover plate 41 is smaller than the width of the battery cell 2 to ensure that the first cover plate 41 only blocks the stress-cut surface 22 in the middle of the cut surface of the battery cell 2, and does not block the laser-cut surfaces 21 on both sides of the stress-cut surface 22. This ensures that the thickness of the first passivation layer deposited on the laser-cut surface 21 is greater than the thickness of the first passivation layer deposited on the stress-cut surface 22. For example, the width of the first cover plate 41 can be less than or equal to 170mm. In this embodiment, the width refers to the width in the direction of the arrangement of the laser-cut surface 21 and the stress-cut surface 22.
[0064] This embodiment does not limit the specific position of the first cover plate 41. For example, the first cover plate 41 can be movably connected to the material box 5 that holds the battery cells 2 and cover the surface of the stress-cut surface 22. Figure 5 As shown; or, the first cover plate 41 is movably connected to the flow equalization plate 3 and covers all the air inlets 31 corresponding to the stress cutting surface 22. Furthermore, in this embodiment, the material box 5 may also be provided with a tooling fixture for fixing the battery cell 2; correspondingly, the first cover plate 41 can be movably connected to the tooling fixture.
[0065] This embodiment does not limit the specific method of movable connection; the movable connection can be, but is not limited to, a snap-fit connection. This embodiment does not limit the specific type of the first cover plate 41; the first cover plate 41 can be, but is not limited to, an aluminum cover plate.
[0066] (2) Please refer to Figure 6The gas flow control device may further include a second cover plate 42; the second cover plate 42 covers a portion of the air inlets 31 corresponding to the stress-cut surface 22. This structure, by adding a second cover plate 42 at the location of the air inlets 31 corresponding to the stress-cut surface 22, partially blocks the air inlets 31 in that area, altering the air intake structure. This makes the air inlets 31 corresponding to the stress-cut surface 22 sparser, while the air inlets 31 corresponding to the laser-cut surface 21 are denser, which is beneficial for depositing a thicker first passivation layer on the laser-cut surface 21. By adjusting the number or coverage area of the second cover plate 42, the density of the air inlets 31 can be changed. By adjusting the density of the air inlets 31 according to the actual required thickness of the first passivation layer, the thickness of the first passivation layer deposited on the stress-cut surface 22 and the laser-cut surface 21 can be freely adjusted, and selective passivation can be achieved with only one passivation operation.
[0067] (3) Please refer to Figure 7 The gas flow control device may further include a third cover plate 43; the third cover plate 43 is provided with flow guide holes 431, and the density of the flow guide holes 431 corresponding to the laser-cut surface 21 is greater than the density of the flow guide holes 431 corresponding to the stress-cut surface 22, and is disposed between the flow equalization plate 3 and the battery cell 2. This structure, by adding a third cover plate 43 with flow guide holes 431 at the middle position of the reaction chamber 1, with sparse flow guide holes 431 corresponding to the stress-cut surface 22 and dense flow guide holes 431 corresponding to the laser-cut surface 21 resembling a honeycomb structure, can autonomously adjust to increase the difference in the thickness of the first passivation layer at different positions, and only requires one passivation to achieve the purpose of selective passivation.
[0068] This embodiment does not limit the specific position of the third cover plate 43. For example, the distance between the third cover plate 43 and the battery cell 2 can be less than 50mm. This embodiment does not limit the specific arrangement of the third cover plate 43. The third cover plate 43 can be connected to the side wall of the reaction chamber 1 in the circumferential direction, but is not limited to this.
[0069] Furthermore, in order to improve the control effect of the third cover plate 43 on the flow rate of the reaction gas 61, the gas flow control device in this embodiment may also include four isolation plates alternately arranged in the circumferential direction; the isolation plates are arranged between the flow equalization plate 3 and the third cover plate 43, and the connection area between the inlet area of the reaction gas 61 and the inlet area of the isolation gas 62 is connected to one end of the isolation plate, and the other end of the isolation plate is connected to the third cover plate 43.
[0070] S103: Thin film deposition based on reactive gas to form a first passivation layer on the cutting surface; the thickness of the first passivation layer on the laser cutting surface is greater than the thickness of the first passivation layer on the stress cutting surface; the thickness difference between the first passivation layer on the laser cutting surface and the first passivation layer on the stress cutting surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
[0071] When this embodiment uses the gas flow control device including the flow equalizer 3, step S103 in this embodiment may include:
[0072] The turntable at the bottom of the reaction chamber 1 drives the battery cell 2 to rotate in the circumferential direction, so that the reaction gas 61 and the isolation gas 62 flow alternately to the battery cell 2, and thin film deposition is performed based on the reaction gas 61 to form a first passivation layer on the cut surface.
[0073] The gas flow control device used in this embodiment is different, and correspondingly, the method of thin film deposition is also different.
[0074] Taking the gas flow control device employing the above structure (1) as an example, step S103 in this embodiment may include:
[0075] The first thin film deposition is performed based on the reactive gas 61 to form the first passivation layer on the laser-cut surface 21.
[0076] After the first passivation layer is formed, the first cover plate 41 is removed;
[0077] After removing the first cover plate 41, a second thin film deposition is performed based on the reactive gas 61 to form a second first passivation layer on the laser-cut surface 21 and the stress-cut surface 22.
[0078] It should be noted that in this embodiment, the laser cutting surface 21 is provided with two first passivation layers, namely a first passivation layer and a second first passivation layer, while the stress cutting surface 22 is only provided with a second first passivation layer, thus achieving a thickness of the first passivation layer of the laser cutting surface 21 being greater than the thickness of the first passivation layer of the stress cutting surface 22.
[0079] It should be noted that when the gas flow control device with the above-mentioned structure (2) and structure (3) is used in this embodiment, step S103 in this embodiment may include: performing a thin film deposition based on the reaction gas 61 to form a first passivation layer on the cutting surface.
[0080] This embodiment does not limit the specific thin film deposition method; it can be, but is not limited to, using ALD (Atomic Layer Deposition). In this case, the coating equipment used in this embodiment can be understood as a spatial ALD equipment.
[0081] When this embodiment uses ALD (Atomic Layer Deposition) for thin film deposition, before step S102, the following is also included:
[0082] The interior of reaction chamber 1 is heated by heating devices installed at the bottom and side walls of reaction chamber 1;
[0083] The interior of reaction chamber 1 is evacuated.
[0084] It should be noted that the heating devices at the bottom and sidewalls of the reaction chamber 1 in this embodiment can assist in the deposition of the first passivation layer. This embodiment does not limit the specific type of heating device; the heating device can be, but is not limited to, a heating lamp.
[0085] Step S103 includes:
[0086] Thin film deposition is performed based on reactive gas 61, and the film is heated and annealed by heating devices provided at the bottom and side walls of the reaction chamber 1 to form a first passivation layer on the cut surface.
[0087] After cooling the inside of the reaction chamber 1, the battery cell 2, which forms the first passivation layer, is removed from the reaction chamber 1.
[0088] Furthermore, after step S103, this embodiment may further include: connecting an outlet pipe through an outlet hole 11 provided at the bottom of the reaction chamber 1, so that the reaction gas 61 can be discharged through the outlet pipe. Based on the above embodiment, this application uses a reaction gas spray coating method. A gas flow control device is provided on the flow path of the reaction gas. The flow rate of the reaction gas is controlled by the gas flow control device so that the flow rate of the reaction gas flowing to the laser cutting surface is greater than the flow rate of the reaction gas flowing to the stress cutting surface. This achieves differentiated control of the thickness of the first passivation layer deposited on the laser cutting surface and the stress cutting surface, ensuring that the thickness of the first passivation layer deposited on the laser cutting surface can be greater than the thickness of the first passivation layer deposited on the stress cutting surface, thereby improving the flatness of the passivation layer on the cutting surface and thus improving the passivation effect of the cutting surface.
[0089] The following examples illustrate the beneficial effects of the above-described coating method. The coating method in this embodiment is based on... Figure 5 The coating equipment shown includes: a reaction chamber 1, a gas flow control device, and a material box 5;
[0090] The gas flow control device includes a flow equalization plate 3 and a second cover plate 42. The flow equalization plate 3 has an array of air inlets 31, which are located at the air inlet end. The flow equalization plate 3 has air inlets 31 arranged in a circular array, and the air inlets 31 in each reactive gas 61 air inlet area and each isolation gas 62 air inlet area are arranged in a fan-shaped array. The arrangement direction of the laser cutting surface 21 and the stress cutting surface 22 is parallel to the radial direction of the fan-shaped array. The flow equalization plate 3 includes two reactive gas 61 air inlet areas and two isolation gas 62 air inlet areas arranged alternately in the circumferential direction. The two reactive gas 61 air inlet areas are used to introduce different reactive gases 61. The isolation gas 62 air inlet area is used to introduce isolation gases 62. A turntable at the bottom of the reaction chamber 1 is used to drive the battery cell 2 to rotate in the circumferential direction, so that the reactive gas 61 air inlet area and the isolation gas 62 air inlet area alternately correspond to the battery cell 2. The second cover plate 42 covers part of the air inlets 31 corresponding to the stress cutting surface 22.
[0091] The reactive gas 61 enters the interior of the reaction chamber 1 through the gas inlet end of the reaction chamber 1; the interior of the reaction chamber 1 is used to place the battery cell 2; the cut surface of the battery cell 2 faces the gas inlet end; the cut surface includes a laser cut surface 21 and a stress cut surface 22; in the length direction of the cut surface, the laser cut surface 21 is located at both ends of the cut surface, and the stress cut surface 22 is located between the two laser cut surfaces 21.
[0092] A gas flow control device is installed on the flow path of the reaction gas 61 to control the flow rate of the reaction gas 61, so that the flow rate of the reaction gas 61 flowing to the laser cutting surface 21 is greater than the flow rate of the reaction gas 61 flowing to the stress cutting surface 22.
[0093] The material box 5 is used to place at least one battery cell 2, and the battery cells 2 are stacked along the thickness direction; the bottom of the reaction chamber 1 is provided with a vent 11; the vent 11 is used to connect to the vent pipe; the bottom and side walls of the reaction chamber 1 are provided with heating devices.
[0094] The coating process using the aforementioned coating equipment specifically includes: the battery cell 2 alternately enters four chambers—TMA, nitrogen (for isolation), water, and nitrogen (for isolation)—alternatingly via a rotary table; the process includes loading, heating and vacuuming, pre-gasification, coating deposition, heating and annealing (at 240℃ for 10 min), and cooling out of the chambers; the deposition conditions include a TMA flow rate of 4.85 slm, a water flow rate of 4.8 slm, a nitrogen flow rate of 200 + 200 sccm, a temperature of 180℃, a time of 700 s, and a pressure of 5 mbar. It has been verified that by changing the density of the air inlet 31, the first passivation layer formed in the dense area of the air inlet 31 (laser-cut surface 21) can be more than 10 nm higher than the first passivation layer formed in the sparse area of the air inlet 31 (stress-cut surface 22).
[0095] This document uses specific examples to illustrate the principles and implementation methods of this application. The various embodiments are progressive, with each embodiment focusing on its differences from others. Similar or identical parts between embodiments can be referred to interchangeably. The descriptions of the embodiments above are merely illustrative of the method and core ideas of this application. For those skilled in the art, various improvements and modifications can be made to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this application.
[0096] It should also be noted that, in this specification, 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. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.
Claims
1. A battery structure, characterized in that, include: Battery cells; The battery cell has at least one cut surface; the cut surface is provided with a first passivation layer; the cut surface includes a laser-cut surface and a stress-cut surface; in the length direction of the cut surface, the laser-cut surface is located at both ends of the cut surface, and the stress-cut surface is located between the two laser-cut surfaces; the thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the first passivation layer located on the stress-cut surface. The thickness difference between the first passivation layer located on the laser cutting surface and the first passivation layer located on the stress cutting surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
2. The battery structure according to claim 1, characterized in that, The first passivation layer includes a SiO2 layer and an AlO layer. x Any one of the following: a layer, a gallium oxide layer, or a zirconium oxide layer; And / or, the average thickness of the first passivation layer is 30nm-100nm, including the values at both ends.
3. The battery structure according to claim 1, characterized in that, The two ends where the battery cell intersects with the cut surface are the first non-cut surfaces, and the first passivation layer is deposited around the two first non-cut surfaces on the battery cell; in the length direction of the first non-cut surfaces, the length of the first passivation layer deposited around the first non-cut surfaces is not greater than 10mm.
4. The battery structure according to claim 2, characterized in that, Hydrogen-rich AlO is disposed on the surface opposite to the first passivation layer. x Layer, hydrogen-rich SIN x Layer, hydrogen-rich SiO x Layer, hydrogen-rich silicon oxynitride, hydrogen-rich SiO x N y Layer or hydrogen-rich AlN x Any of the layers.
5. The battery structure according to claim 1, characterized in that, The side surface of the battery cell opposite to the cut surface is a second non-cut surface; the second non-cut surface is provided with a second passivation layer; the thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the second passivation layer.
6. The battery structure according to claim 5, characterized in that, The second passivation layer includes an aluminum oxide layer and a silicon nitride layer stacked together; the thickness of the aluminum oxide layer is 4nm-8nm, including the values at both ends; the thickness of the silicon nitride layer is 70nm-90nm, including the values at both ends.
7. The battery structure according to claim 6, characterized in that, The second passivation layer further includes any one or more of a silicon nitride layer, a silicon oxynitride layer, or a silicon oxide layer.
8. A battery assembly, characterized in that, include: The battery structure as described in any one of claims 1 to 7.
9. A coating method, characterized in that, include: The battery cell is placed inside the reaction chamber with its cut surface facing the air inlet of the reaction chamber; the cut surface includes a laser-cut surface and a stress-cut surface; along the length of the cut surface, the laser-cut surface is located at both ends of the cut surface, and the stress-cut surface is located between the two laser-cut surfaces; The reactive gas is introduced into the interior of the reaction chamber through the gas inlet, and the flow rate of the reactive gas is controlled by a gas flow control device, so that the flow rate of the reactive gas flowing towards the laser cutting surface is greater than the flow rate of the reactive gas flowing towards the stress cutting surface; the gas flow control device is located on the flow path of the reactive gas. Thin film deposition is performed based on the reactive gas to form a first passivation layer on the cut surface; The thickness of the first passivation layer located on the laser-cut surface is greater than the thickness of the first passivation layer located on the stress-cut surface; The thickness difference between the first passivation layer located on the laser cutting surface and the first passivation layer located on the stress cutting surface is greater than 10 nm, and the outer surface of the first passivation layer is on the same horizontal plane.
10. The coating method according to claim 9, characterized in that, The thin film deposition based on the reactive gas to form a first passivation layer on the cut surface includes: The turntable at the bottom of the reaction chamber drives the battery cell to rotate in the circumferential direction, so that the reaction gas and the isolation gas flow alternately to the battery cell, and the first thin film deposition is performed based on the reaction gas to form the first passivation layer on the laser-cut surface. After the first passivation layer is formed, the first cover plate is removed; After removing the first cover plate, a second thin film deposition is performed based on the reactive gas to form a second layer of the first passivation layer on the laser-cut surface and the stress-cut surface.