A method for producing a battery cell

Abstract

The application relates to a production method of a battery piece, which comprises the following steps: printing a grid electrode on the battery piece; sintering the grid electrode; cutting the battery piece; forming a passivation layer on the cutting edge of the battery piece; and applying voltage and laser to the battery piece to anneal the grid electrode and the passivation layer. In the application, the contact resistance between the grid electrode and the battery piece can be reduced by applying voltage and laser to the battery piece to anneal the grid electrode; the passivation degree of the passivation layer to the cutting edge can be improved by annealing the passivation layer, thereby improving the photoelectric conversion efficiency of the produced battery piece. By applying voltage and laser to the battery piece after the step of forming the passivation layer on the cutting edge of the battery piece, the grid electrode and the passivation layer can be annealed at the same time, the time for repeatedly arranging the voltage and laser applying equipment is saved, the passivation degree of the passivation layer is improved, the production time of the battery piece is reduced, and the production efficiency of the battery piece is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a production method of a cell piece. BACKGROUND

[0002] Solar cells can directly convert solar radiation energy into electrical energy, mainly based on the photovoltaic effect of crystalline silicon, that is, when the light quantum of sunlight is absorbed by the semiconductor crystalline silicon, an electron-hole pair is generated, and when these electron-hole pairs reach the p-n junction composed of p-type crystalline silicon and n-type crystalline silicon, they are separated by the junction electric field to the two sides of the p-n junction, and when an external load is connected, a photoelectric current is formed, and electrical energy is output.

[0003] In recent years, with the rise of component technologies such as cut half components and shingle components, it is necessary to cut the cell piece when manufacturing the component. The edge of the cut cell piece has defects and damage, which increases the recombination of the solar cell at the cutting edge and affects the photoelectric conversion efficiency of the solar cell.

[0004] The prior art reduces the damage caused by cutting the cell piece by depositing a passivation film on the cutting edge of the cell piece, but the passivation effect of the deposited passivation film is limited, and the photoelectric conversion efficiency of the solar cell is still low. SUMMARY

[0005] The present application provides a production method of a cell piece, which is used to improve the photoelectric conversion efficiency of the cell piece.

[0006] The production method of a cell piece provided by the present application embodiment comprises:

[0007] printing a grid electrode on the cell piece;

[0008] sintering the grid electrode;

[0009] cutting the cell piece;

[0010] forming a passivation layer on the cutting edge of the cell piece;

[0011] applying voltage and laser to the cell piece to anneal the grid electrode and the passivation layer.

[0012] In a possible design, in the step of forming a passivation layer on the cutting edge of the cell piece, the passivation layer completely covers the cutting surface of the cell piece and extends to the surface adjacent to the cutting surface of the cell piece.

[0013] In a possible design, the length L of the extension of the passivation layer on the surface adjacent to the cutting surface of the cell piece satisfies: 1mm≤L≤3mm.

[0014] In a possible design, the thickness d of the passivation layer satisfies: 45nm≤d≤60nm.

[0015] In a possible design, the step of applying voltage and laser to the cell piece to anneal the grid line electrode and the passivation layer comprises:

[0016] The grid line electrode and the passivation layer are irradiated with laser while voltage is applied to the grid line electrode.

[0017] In a possible design, when the grid line electrode is irradiated with laser, a plurality of light spots of the laser are arranged along the length direction of the grid line electrode, and the plurality of light spots of the laser are tangent to or intersect with the grid line electrode.

[0018] In a possible design, when the passivation layer is irradiated with laser, a plurality of light spots of the laser are arranged along the length direction of the passivation layer, and the plurality of light spots of the laser are tangent to or intersect with the part of the passivation layer extending to the surface adjacent to the cutting surface of the cell piece.

[0019] In a possible design, when the grid line electrode and the passivation layer are irradiated with laser, the power P of the laser satisfies: 2600W≤P≤2800W.

[0020] In a possible design, the step of applying voltage to the grid line electrode comprises: abutting a probe for applying voltage against the grid line electrode.

[0021] In a possible design, when voltage is applied to the grid line electrode, the applied voltage U satisfies: 15V≤U≤20V.

[0022] In the present application, by applying voltage and laser to the cell piece to anneal the grid line electrode, the mutual diffusion of metal and silicon between the grid line electrode and the cell piece can be triggered, the degree of ohmic contact between the grid line electrode and the cell piece is improved, and the contact resistance between the grid line electrode and the cell piece is reduced. Meanwhile, by applying voltage and laser to the cell piece to anneal the passivation layer, the passivation degree of the passivation layer to the cutting edge is improved, the recombination of the produced cell piece at the cutting edge is further reduced, and the photoelectric conversion efficiency of the produced cell piece is improved.

[0023] In addition, in the prior art, voltage and laser are applied to the battery piece after the step of sintering the grid line electrode and before the step of cutting the battery piece, so as to improve the ohmic contact degree of the grid line electrode and the battery piece. The present application can anneal the grid line electrode and the passivation layer at the same time by applying voltage and laser to the battery piece after the step of forming the passivation layer on the cutting edge of the battery piece, thereby saving the time of repeatedly arranging the equipment for applying voltage and laser, reducing the production time of the battery piece while improving the passivation degree of the passivation layer, and improving the production efficiency of the battery piece.

[0024] It should be understood that the foregoing general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Flow chart of the production method of the battery piece provided by the present application;

[0026] Figure 2 Structure diagram of the battery piece produced by the production method of the battery piece provided by the present application;

[0027] Figure 3 Schematic diagram of irradiating the grid line electrode with laser while applying voltage to the grid line electrode;

[0028] Figure 4 Schematic diagram of irradiating the passivation layer with laser while applying voltage to the grid line electrode.

[0029] Reference signs:

[0030] 1-battery piece;

[0031] 11-grid line electrode;

[0032] 111-main grid;

[0033] 112-sub grid;

[0034] 12-passivation layer;

[0035] 2-probe;

[0036] 3-laser emitting device.

[0037] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0038] In order to better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0039] It should be noted that the embodiments described are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0040] The terms used in the embodiments of the present application are merely for the purpose of describing particular embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are intended to include plural forms, unless the context clearly indicates otherwise.

[0041] It should be understood that the term "and / or" used herein is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0042] It should be noted that the "up", "down", "left", "right" and other directional words described in the embodiments of the present application are described from the angle shown in the drawings, and should not be understood as a limitation on the embodiments of the present application. In addition, in the context, it should also be understood that when referring to an element connected to another element "on" or "under", it can not only be directly connected to another element "on" or "under", but also indirectly connected to another element "on" or "under" through an intermediate element.

[0043] The embodiments of the present application provide a production method of a battery piece 1, as shown in the figure, the production method of the battery piece 1 comprises: Figure 1 As shown in the figure, the production method of the battery piece 1 comprises:

[0044] S1: printing a grid electrode 11 on the battery piece 1.

[0045] In this step, the grid electrode 11 is printed on the battery piece 1 by the process of screen printing, which is a process of extruding the screen elastic deformation by the squeegee to print the paste on the surface to be printed. The battery piece 1 can supply power to the outside through the grid electrode 11.

[0046] S2: sintering the grid electrode 11.

[0047] In this step, the paste on the battery piece 1 can be dried by sintering, and the organic components in the paste are burned out, so that the grid electrode 11 forms ohmic contact with the battery piece 1.

[0048] S3: cutting the battery piece 1.

[0049] In this step, the cutting of the battery piece 1 can be achieved by mechanical cutting, laser cutting, etc., but the edges after cutting have defects and damages, resulting in increased recombination of the produced battery piece 1 and reduced photoelectric conversion efficiency.

[0050] S4: Forming a passivation layer 12 on the cutting edge of the battery piece 1.

[0051] In this step, the passivation layer 12 can reduce the defects and damages of the cutting edge of the battery piece 1, reduce the recombination of the produced battery piece 1, and improve the photoelectric conversion efficiency of the produced battery piece 1. However, the deposited passivation layer 12 still has the problem of incomplete passivation, which limits the improvement of the photoelectric conversion efficiency. The material of the passivation layer 12 can be at least one or more of silicon oxide, aluminum oxide, nickel oxide, and zinc oxide.

[0052] S5: Applying voltage and laser to the battery piece 1 to anneal the grid line electrode 11 and the passivation layer 12.

[0053] In this step, by applying voltage and laser to the battery piece 1 to anneal the grid line electrode 11, the mutual diffusion of metal and silicon between the grid line electrode 11 and the battery piece 1 can be induced, the ohmic contact degree of the grid line electrode 11 and the battery piece 1 can be improved, and the contact resistance between the grid line electrode 11 and the battery piece 1 can be reduced. At the same time, by applying voltage and laser to the battery piece 1 to anneal the passivation layer 12, the passivation degree of the passivation layer 12 on the cutting edge can be improved, the damage of the battery piece 1 at the cutting edge can be reduced, and thus the recombination of the produced battery piece 1 at the cutting edge can be reduced, and the photoelectric conversion efficiency of the produced battery piece 1 can be improved.

[0054] In addition, in the prior art, voltage and laser are generally applied to the battery piece 1 after step S2: sintering the grid line electrode 11 and before step S3: cutting the battery piece 1, to improve the ohmic contact degree of the grid line electrode 11 and the battery piece 1. The present scheme applies voltage and laser to the battery piece 1 after step S4: forming a passivation layer 12 on the cutting edge of the battery piece 1, which can simultaneously anneal the grid line electrode 11 and the passivation layer 12, save the time of repeatedly arranging the device for applying voltage and laser, and reduce the production time of the battery piece 1 while improving the passivation degree of the passivation layer 12, thereby improving the production efficiency of the battery piece 1.

[0055] In a specific embodiment, as shown in Figure 2 and Figure 3 In the step of forming a passivation layer 12 on the cutting edge of the battery piece 1, the passivation layer 12 completely covers the cutting surface of the battery piece 1 and extends to the surface adjacent to the cutting surface of the battery piece 1.

[0056] In the present embodiment, as shown in Figure 2 and Figure 3As shown, if the passivation layer 12 only covers the cutting surface of the battery piece 1, the edge position of the passivation layer 12 is aligned with the edge position of the cutting surface, and the passivation effect of the passivation layer 12 on the edge position of the cutting surface is poor, and the recombination of the produced battery piece 1 at the position is high. Therefore, extending a part of the passivation layer 12 to the surface adjacent to the cutting surface of the battery piece 1 can improve the passivation effect of the passivation layer 12 on the cutting surface, reduce the recombination of the produced battery piece 1, and further improve the photoelectric conversion efficiency of the produced battery piece 1.

[0057] Specifically, as shown in FIG. 1, the length L of the passivation layer 12 extending on the surface adjacent to the cutting surface of the battery piece 1 satisfies: 1 mm≤L≤3 mm. For example, the length L can be specifically 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 3 mm, etc. Figure 2

[0058] The length L of the passivation layer 12 extending on the surface adjacent to the cutting surface of the battery piece 1 should not be too long or too short. If the length L of the passivation layer 12 extending on the surface adjacent to the cutting surface of the battery piece 1 is too short (for example, shorter than 1 mm), the passivation effect of the passivation layer 12 on the edge position of the cutting surface can be poor. If the length L of the passivation layer 12 extending on the surface adjacent to the cutting surface of the battery piece 1 is too long (for example, longer than 3 mm), the passivation layer 12 can be in contact with the auxiliary grid 112, affecting the connection effect of the auxiliary grid 112 and the battery piece 1, and the shielding of the passivation layer 12 on the light-receiving surface of the battery piece 1 also reduces the photoelectric conversion efficiency of the battery piece 1. Therefore, the length L of the passivation layer 12 extending on the surface adjacent to the cutting surface of the battery piece 1 should be set within a reasonable range.

[0059] Specifically, as shown in FIG. 1, the thickness d of the passivation layer 12 satisfies: 45 nm≤d≤60 nm. For example, the thickness of the passivation layer 12 can be specifically 45 nm, 48 nm, 50 nm, 52 nm, 54 nm, 56 nm, 58 nm, 60 nm, etc. Figure 3

[0060] The thickness of the passivation layer 12 should not be too thick or too thin. If the thickness of the passivation layer 12 is too thin (for example, thinner than 45 nm), the passivation effect of the passivation layer 12 on the cutting edge will be poor, the recombination of the produced battery piece 1 will increase, and the photoelectric conversion efficiency will increase. If the thickness of the passivation layer 12 is too thick (for example, thicker than 60 nm), the time required to deposit the passivation layer 12 increases, and the production efficiency of the battery piece 1 is low. Therefore, the thickness of the passivation layer 12 should be selected within a reasonable range.

[0061] Optionally, the passivation layer is formed at the cutting edge of the battery piece 1 by an atomic layer deposition (ALD) method. ​​

[0062] In one specific embodiment, as shown in Figure 3 and Figure 4 The step of applying voltage and laser to the cell sheet 1 to anneal the grid line electrode 11 and the passivation layer 12 includes: irradiating the grid line electrode 11 and the passivation layer 12 with laser while applying voltage to the grid line electrode 11.

[0063] In the step of forming the passivation layer 12 at the cutting edge of the cell sheet 1, since the required time length is 1-3h and the process temperature is 240-260℃, the step will cause the contact resistance between the grid line electrode 11 and the cell sheet 1 to increase and more defects to occur inside the cell sheet 1 in addition to forming the passivation layer 12 at the cutting edge of the cell sheet 1.

[0064] Therefore, irradiating the grid line electrode 11 with laser will cause very high charge carrier injection at the position of the grid line electrode 11 on the cell sheet 1. Under the action of a certain voltage, local high current density and transient high temperature will occur at the contact interface between the grid line electrode 11 and the cell sheet 1, thereby causing mutual diffusion of metal and silicon, improving the ohmic contact degree between the grid line electrode 11 and the cell sheet 1, and reducing the contact resistance between the grid line electrode 11 and the cell sheet 1. Meanwhile, the thermal effect of laser on the grid line electrode 11 and the thermal effect of voltage on the cell sheet 1 can also reduce defects inside the cell sheet 1 to reduce recombination inside the cell sheet 1.

[0065] Similarly, applying voltage to the grid line electrode 11 will generate thermal effect at the cutting edge of the cell sheet 1. Under the combined action of temperature and laser, the crystallinity of the passivation layer 12 can be improved, thereby improving the passivation effect of the passivation layer 12 on the cutting edge.

[0066] It can be understood that laser can be first irradiated to the grid line electrode 11 and then to the passivation layer 12, or laser can be first irradiated to the passivation layer 12 and then to the grid line electrode 11. In addition, when two sets of laser irradiation mechanisms are provided, the two sets of laser irradiation mechanisms can simultaneously irradiate laser to the grid line electrode 11 and the passivation layer 12.

[0067] More specifically, the laser emitting device 3 can emit laser for irradiating the grid line electrode 11 or the passivation layer 12. The laser emitted by the laser emitting device 3 forms spots arranged in the same direction on the cell sheet 1.

[0068] As shown in Figure 3 When the step of irradiating the grid line electrode 11 with laser, the multiple spots of laser are arranged along the length direction of the grid line electrode 11, and the multiple spots of laser are tangent to or intersect with the grid line electrode 11.

[0069] The diameter of the laser spot is generally smaller than the diameter of the grid electrode 11. Since the laser contains high energy, the laser spot can generate a high thermal effect at the grid electrode 11 of the solar cell 1 when it is tangent to or intersects with the grid electrode 11.

[0070] like Figure 4 As shown, in step 1, when the passivation layer 12 is irradiated with a laser, multiple laser spots are arranged along the length of the passivation layer 12, and these laser spots are tangential to or intersect with the portion of the passivation layer 12 that extends to the surface adjacent to the cut surface of the battery cell 1. Specifically, the laser emitted by the laser emitting device 3 can conveniently irradiate the portion of the passivation layer 12 that extends to the surface adjacent to the cut surface of the battery cell 1.

[0071] Similarly, when the laser spot is tangent to or intersects with a portion of the passivation layer 12 extending to the surface adjacent to the cut surface of the battery cell 1, a high thermal effect can be generated at the passivation layer 12 of the battery cell 1, and this thermal effect can affect the back surface of the battery cell 1 from the light-receiving surface of the battery cell 1.

[0072] Furthermore, in step 1, when the grid electrode 11 is irradiated with a laser, the laser power P satisfies the condition: 2600W ≤ P ≤ 2800W. For example, the laser power can specifically be: 2600W, 2630W, 2650W, 2680W, 2700W, 2730W, 2750W, 2780W, 2800W, etc.

[0073] The laser power should not be too high or too low. If the laser power is too high (e.g., greater than 2800W), the grid electrode 11 may be over-sintered, causing it to collapse to both sides, increasing the area of ​​obstruction to the solar cell 1, or causing the grid electrode 11 to shrink, increasing the contact resistance between the grid electrode 11 and the solar cell 1, thus reducing the photoelectric conversion efficiency of the produced solar cell 1. If the laser power is too low (e.g., less than 2600W), it may not effectively improve the contact between the grid electrode 11 and the solar cell 1, affecting the photoelectric conversion efficiency of the produced solar cell 1. Therefore, the laser power P should be selected within a reasonable range.

[0074] Similarly, in step 12, when the passivation layer 12 is irradiated with a laser, the laser power P satisfies the following condition: 2600W ≤ P ≤ 2800W. For example, the specific laser power can be: 2600W, 2630W, 2650W, 2680W, 2700W, 2730W, 2750W, 2780W, 2800W, etc.

[0075] The power of the laser should not be too large or too small. If the power of the laser is too large (for example, greater than 2800 W), the passivation layer 12 can be damaged, which increases the recombination of the cutting edge of the battery piece 1, and thus reduces the photoelectric conversion efficiency of the produced battery piece 1. If the power of the laser is too low (for example, less than 2600 W), the passivation effect of the passivation layer 12 cannot be improved or is limited, which affects the photoelectric conversion efficiency of the produced battery piece 1. Therefore, the power P of the laser should be selected within a reasonable range.

[0076] Further, the wavelength of the laser irradiating the grid line electrode 11 can be 532 nm or 1064 nm, and the wavelength of the laser irradiating the passivation layer 12 can be 532 nm or 1064 nm. When the wavelength of the laser is 532 nm, the laser is green light. When the wavelength of the laser is 1064 nm, the laser is red light.

[0077] In some specific embodiments, as shown in FIGS. 1A and 1B, the grid line electrode 11 includes a main grid 111 and a plurality of sub-grids 112, and each of the plurality of sub-grids 112 is electrically connected to the main grid 111. Figure 2 and Figure 3 As shown in FIGS. 1A and 1B, the grid line electrode 11 includes a main grid 111 and a plurality of sub-grids 112, and each of the plurality of sub-grids 112 is electrically connected to the main grid 111.

[0078] The step of applying a voltage to the grid line electrode 11 includes: abutting the probe 2 used for applying the voltage to the main grid 111.

[0079] In this step, the probe 2 connected to the power source is abutted to the grid line electrode 11, so that a voltage can be applied to the grid line electrode 11. Since each of the plurality of sub-grids 112 is electrically connected to the main grid 111, the probe 2 can be electrically connected to each of the plurality of sub-grids 112 by being electrically connected to the main grid 111.

[0080] The cross-sectional size of the main grid 111 is greater than that of the sub-grid 112, so the main grid can be more easily identified, and the probe 2 can more easily abut to the grid line electrode 11 to apply a voltage thereto.

[0081] Preferably, the number of probes 2 is consistent with the number of sub-grids 112 on the battery piece 1, and each probe 2 is abutted to the position on the main grid 111 where the sub-grid 112 is connected, so as to facilitate the application of a voltage to each sub-grid 112, and to make the current and heat effects generated by the probes 2 applying a voltage to the battery piece 1 more balanced on the battery piece 1. It can be understood that the number of probes 2 can also be less than the number of sub-grids 112 on the battery piece 1.

[0082] In addition, the plurality of probes 2 can be integrated on one probe row, which facilitates the plurality of probes 2 to be abutted to the grid line electrode 11 simultaneously. The plurality of probes 2 can be abutted to the same main grid 111, or can be abutted to different main grids 111 respectively.

[0083] In some other embodiments, the grid line electrode 11 only includes the auxiliary grid 112, and does not include the main grid 111, i.e., a main grid-free cell sheet in which only the auxiliary grid 112 is arranged. For the main grid-free cell sheet, the step of applying a voltage to the grid line electrode 11 includes abutting the probe 2 for applying the voltage against the auxiliary grid 112.

[0084] Further, the voltage applied to the grid line electrode 11 by the probe 2 when the grid line electrode 11 is irradiated with the laser can be the same as or different from the voltage applied to the grid line electrode 11 by the probe 2 when the passivation layer 12 is irradiated with the laser. It can be understood that the voltage applied to the grid line electrode 11 by the probe 2 can be adjusted within a reasonable range according to actual working conditions, and the moving speed, power, and wavelength of the laser irradiating the grid line electrode 11 can be adjusted within a reasonable range according to actual working conditions.

[0085] Specifically, when the voltage is applied to the grid line electrode 11 in the step, the applied voltage U satisfies 15V≤U≤20V. The applied voltage U can be specifically 15V, 16V, 16.5V, 17V, 18V, 18.5V, 19V, 20V, etc.

[0086] The voltage applied to the grid line electrode 11 should not be too large or too small. If the applied voltage is too large (e.g., greater than 20V), the temperature of the cell sheet 1 is easily too high, the grid line electrode 11 is excessively sintered, at this time, the grid line electrode 11 collapses to both sides, increases the shielding area of the cell sheet 1 or the grid line electrode 11 shrinks, the contact resistance between the grid line electrode 11 and the cell sheet 1 increases, and the photoelectric conversion efficiency of the produced cell sheet 1 is reduced. If the applied voltage is too small (e.g., greater than 15V), the thermal effect of the voltage on the cell sheet 1 is limited, the temperature of the cell sheet 1 is low, it is difficult to improve the ohmic contact degree between the grid line electrode 11 and the cell sheet 1, and it is also difficult to improve the passivation effect of the passivation layer 12 on the cutting edge. Therefore, the value of the voltage applied to the grid line electrode 11 should be set within a reasonable range.

[0087] In the above embodiments, the cell sheet 1 can be one of a PERC cell (Passivated Emitter and Rear Cell), a PERT cell (Passivated Emitter and Rear Totally-diffused cell), a TOPCON cell (Tunnel Oxide Passivated Contact), and an HJT cell (Heterojunction Technology).

[0088] In the present application, by forming a passivation layer 12 on the cutting edge of the battery piece 1, and then irradiating the grid line electrode 11 and the passivation layer 12 with a laser while applying a voltage to the grid line electrode 11, the degree of ohmic contact between the grid line electrode 11 and the battery piece 1 can be improved, the contact resistance between the grid line electrode 11 and the battery piece 1 can be reduced, the crystallinity of the passivation layer 12 can be improved, the passivation effect of the passivation layer 12 on the cutting edge can be improved, and the photoelectric conversion efficiency of the battery piece 1 produced in this way can be improved by 0.05% relative to the photoelectric conversion efficiency of the existing battery piece 1, and the power of the photovoltaic module assembled and produced from the battery piece 1 can be increased by 1W.

[0089] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of producing a battery sheet, characterized by, The production method of the battery piece (1) includes: printing a grid electrode (11) on the battery piece (1); sintering the grid electrode (11); cutting the battery piece (1); forming a passivation layer (12) on the cutting edge of the battery piece (1); applying voltage and laser to the battery piece (1) to anneal the grid electrode (11) and the passivation layer (12); The step of applying voltage and laser to the battery piece (1) to anneal the grid electrode (11) and the passivation layer (12) includes: irradiating the grid electrode (11) and the passivation layer (12) with laser while applying voltage to the grid electrode (11).

2. The method of producing a battery cell according to claim 1, wherein In the step of forming a passivation layer (12) on the cutting edge of the battery piece (1), the passivation layer (12) completely covers the cutting surface of the battery piece (1) and extends onto the surface adjacent to the cutting surface of the battery piece.

3. The method of producing a battery cell according to claim 2, wherein The length L of the passivation layer (12) extending on the surface adjacent to the cutting surface of the battery piece (1) satisfies: 1mm≤L≤3mm.

4. The method of producing a battery cell according to claim 2, wherein The thickness d of the passivation layer (12) satisfies: 45nm≤d≤60nm.

5. The method of producing a battery cell according to claim 1, wherein In the step of irradiating the grid electrode (11) with laser, a plurality of light spots of the laser are arranged along the length direction of the grid electrode (11), and the plurality of light spots of the laser are tangent to or intersect with the grid electrode (11).

6. The method of producing a battery cell according to claim 1, wherein In the step of irradiating the passivation layer (12) with laser, a plurality of light spots of the laser are arranged along the length direction of the passivation layer (12), and the plurality of light spots of the laser are tangent to or intersect with the part of the passivation layer (12) extending onto the surface adjacent to the cutting surface of the battery piece (1).

7. The method of producing a battery cell according to claim 1, wherein In the step of irradiating the grid electrode (11) and the passivation layer (12) with laser, the power P of the laser satisfies: 2600W≤P≤2800W.

8. The method of producing a battery cell according to claim 1, wherein The step of applying voltage to the grid electrode (11) includes: abutting a probe (2) for applying voltage with the grid electrode (11).

9. The method of producing a battery sheet according to any one of claims 1 to 8, characterized by, In the step of applying voltage to the grid electrode (11), the applied voltage U satisfies: 15V≤U≤20V.

Images