Electrode extraction method and structure of perovskite battery for spacecraft

Abstract

The invention provides an electrode leading-out structure and method of a perovskite battery for a spacecraft. The electrode leading-out structure comprises a perovskite battery body, a Cr / Cu composite welding layer and an external metal electrode plate welded on the upper surface of the Cr / Cu composite welding layer, according to the perovskite battery electrode leading-out structure and method for the spacecraft, the Cr / Cu metal layers are evaporated on the edge areas of the two sides of the positive electrode and the negative electrode of the perovskite battery to serve as the welding areas, damage to the perovskite functional layer caused by high temperature is effectively avoided, meanwhile, the strength and stability of a welding contact are remarkably improved, and the service life of the perovskite battery is prolonged. Therefore, reliable operation of the perovskite battery for the spacecraft in a complex environment is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a method and structure for leading out electrodes of a perovskite battery for spacecraft. Background Art

[0002] Perovskite solar cells, due to their high photoelectric conversion efficiency, flexible fabrication, and low cost, hold great promise for application in spacecraft energy systems. However, their long-term reliability in the extreme environment of space faces significant challenges, with the stability of the electrode lead structure being a key bottleneck restricting their engineering applications.

[0003] Traditional electrode extraction processes typically use direct welding to connect metal wires to the positive and negative electrodes of the battery. This method has the following inherent drawbacks:

[0004] 1. Thermal damage sensitivity: The perovskite functional layer is extremely sensitive to high temperatures. Soldering temperatures exceeding 150°C can cause material decomposition. Conventional soldering processes (300-350°C) generate localized high temperatures that are directly transferred to the functional layer, causing irreversible lattice damage. Experiments have shown that direct soldering can reduce the cell's photoelectric conversion efficiency (PCE) by more than 5%, severely limiting cell output performance.

[0005] 2. Insufficient mechanical strength of solder joints: The bonding strength between the battery's back electrode layer (such as Au, Ag, etc.) and the substrate and functional layers is limited, making it prone to delamination and detachment under the thermal stress of welding. The average tensile strength of existing solder joints is less than 15N, far below the reliability requirement of >30N for spacecraft mechanical connectors. This can easily lead to connection failure in the intense vibration environment during launch.

[0006] 3. Inadequate adaptability to the space environment: Spacecraft operating in orbit must withstand harsh conditions such as extreme temperature fluctuations ranging from -90°C to 100°C, high vacuum, and intense radiation. Conventional electrode lead structures are susceptible to stress concentration due to material thermal expansion coefficient mismatch during high-low temperature cycling, leading to solder joint cracking or increased contact resistance. Atomic diffusion or oxidation may occur at the solder joint interface in a vacuum environment, further reducing the long-term stability of the connection. Existing methods make it difficult to ensure that the electrode lead structure maintains a low-loss electrical connection and sufficient mechanical integrity under such extreme conditions.

[0007] Therefore, there is an urgent need to develop a new electrode lead-out method and structure that can avoid thermal damage while meeting aerospace-grade mechanical strength and environmental adaptability. Summary of the Invention

[0008] In response to the above technical problems, the purpose of the present invention is to provide a method and structure for electrode lead-out of perovskite batteries for spacecraft. By evaporating a Cr / Cu metal layer on the edge areas of the positive and negative electrodes of the perovskite battery as a welding area, it can effectively avoid damage to the perovskite functional layer caused by high temperature, and at the same time significantly improve the strength and stability of the welding joints, thereby ensuring the reliable operation of perovskite batteries for spacecraft in complex environments.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The first aspect of the present invention is to provide a perovskite battery electrode lead-out structure for a spacecraft, comprising:

[0011] The perovskite battery body has a battery positive electrode and a battery negative electrode. The battery positive electrode is defined by a P3 channel on the positive electrode side edge formed by P3 laser scribing, and the battery negative electrode is defined by a P2 channel on the negative electrode side edge formed by P2 laser scribing. The edge area around the perovskite battery body is provided with a laser edge cleaning zone, and the back electrode layer and functional film layer in the laser edge cleaning zone are completely removed to expose the substrate.

[0012] A Cr / Cu composite welding layer is provided at the edge areas of the positive and negative electrodes of the perovskite battery body, comprising a Cr metal layer with a thickness of 5nm to 10nm directly contacting the substrate and a Cu metal layer with a thickness of 110nm to 200nm covering the Cr metal layer;

[0013] The positive electrode side Cr / Cu composite welding layer completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, and does not exceed the positive electrode side edge P3 channel; the negative electrode side Cr / Cu composite welding layer completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, and does not exceed the negative electrode side edge P2 channel;

[0014] External metal electrode sheets, including two positive external metal electrode sheets welded on the upper surface of the Cr / Cu composite welding layer on the positive side and two negative external metal electrode sheets welded on the upper surface of the Cr / Cu composite welding layer on the negative side. The length of the contact part between the external metal electrode sheets and the Cr / Cu composite welding layer is 2 to 3 mm, and the area is 10 to 30 mm. 2 .

[0015] Furthermore, the width of the laser edge cleaning area is 3.5 mm to 3.8 mm.

[0016] Furthermore, the Cr / Cu composite welding layer has a length of 30 to 40 mm and a width of 4 to 4.5 mm.

[0017] Furthermore, the distance between the two positive external metal electrode sheets is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets is 6 mm to 10 mm.

[0018] Furthermore, the material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

[0019] Furthermore, the back electrode layer is made of gold, silver, copper or aluminum, and has a thickness of 100 to 200 nm.

[0020] A second aspect of the present invention is to provide a method for extracting electrodes of a perovskite battery for a spacecraft, comprising the following steps:

[0021] S0. Forming the positive and negative electrode structures of the perovskite battery: forming a P3 channel on the positive electrode side edge on the perovskite battery body by P3 laser scribing to define the positive electrode of the battery; forming a P2 channel on the negative electrode side edge by P2 laser scribing to define the negative electrode of the battery;

[0022] S1. Laser edge cleaning: Use laser to perform P4 edge cleaning on the perovskite cell, removing all back electrode layers and functional film layers around the edge until the substrate is exposed, forming a laser edge cleaning area;

[0023] S2. Preparation of a Cr / Cu composite welding layer: On the edge areas of the positive and negative electrodes of the perovskite cell that have been treated with P4 laser edge cleaning, a 5-10 nm thick Cr metal layer is first prepared. Then, a 110-200 nm thick Cu metal layer is prepared to cover the Cr metal layer, forming a Cr / Cu composite welding layer as the welding area.

[0024] The positive electrode side Cr / Cu composite welding layer completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, and does not exceed the positive electrode side edge P3 channel; the negative electrode side Cr / Cu composite welding layer completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, and does not exceed the negative electrode side edge P2 channel;

[0025] S3. External metal electrode sheet welding: Weld two external metal electrode sheets to the upper surface of the Cr / Cu composite welding layer on the positive side and the upper surface of the Cr / Cu composite welding layer on the negative side respectively. The welding temperature is 300-350°C and the welding time is 5-10s. The length of the contact part between the external metal electrode sheet and the Cr / Cu composite welding layer is 2-3mm and the area is 10-30mm. 2 .

[0026] Furthermore, in step S1, the width of the edge clearing P4 is 3.5 mm to 3.8 mm.

[0027] Furthermore, in step S2, the Cr / Cu composite welding layer is prepared by thermal evaporation, and the evaporation rate of the Cr metal layer is Cu metal layer evaporation rate

[0028] Furthermore, in step S2, the length of the Cr / Cu composite welding layer is 30-40 mm, and the width is 4-4.5 mm.

[0029] Furthermore, in step S3, the distance between the two positive external metal electrode sheets is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets is 6 mm to 10 mm.

[0030] Furthermore, in step S3, the material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

[0031] Furthermore, in step S3, the welding method is laser welding or soldering.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] 1. Thermal damage isolation: The traditional direct welding process causes PCE attenuation > 5%; the present invention prepares a Cr / Cu composite welding layer (Cr metal layer thickness 5-10nm, Cu metal layer thickness 110nm-200nm) at the edges of the positive and negative electrodes of the perovskite battery as the welding area, which can limit the high welding temperature (300-350°C) to the Cr / Cu composite welding layer, so that the heat will not be conducted to the perovskite functional layer (thermal sensitive area), avoiding the heat from high-temperature welding directly contacting the perovskite functional layer, preventing high temperature thermal damage to the perovskite layer, ensuring that the performance of the perovskite light conversion layer is not affected (photoelectric conversion efficiency (PCE) attenuation <0.3%), and achieving reliable conductive connection without damaging the battery performance, thereby improving the efficiency and stability of the perovskite battery.

[0034] 2. Enhance the strength of welding joints: Due to the weak adhesion between the back electrode and other film layers of the perovskite battery, loose joints are likely to occur during welding; the present invention evaporates a Cr / Cu composite welding layer in the edge area of ​​the positive and negative electrodes of the battery as a welding area (the 5-10nm Cr metal layer effectively enhances the adhesion between the external metal electrode sheet and the substrate, and the 110-200nm Cu metal layer provides excellent conductivity and mechanical connectivity between the external metal electrode sheet and the substrate), providing a more stable and stronger welding joint for the external metal electrode sheet, effectively enhancing the mechanical strength and conductivity of the welding joint, and the welding joint tensile force is stable>40N, which is 170% higher than the traditional process (<15N), meeting the mechanical strength requirement of spacecraft>30N, and reducing failures caused by loose welding joints.

[0035] 3. Improve the reliability of batteries in extreme environments: The electrode lead-out method and structure of the present invention can effectively enhance the stability of batteries in extreme aerospace environments by improving the welding area. The perovskite battery containing this structure has passed the high and low temperature cycle test (GJB 322A-2009 standard, after 500 temperature cycles (-90℃~100℃), the PCE decay is less than 5%), the thermal vacuum test (GJB3758-99 standard, after 200h thermal vacuum temperature (100℃, ≤1.3*10 -3 Pa), PCE decay is less than 5%, and the solder joint tensile force remains above 40N) indicating that the perovskite battery containing this structure can work for a long time under high and low temperature cycles and vacuum conditions, significantly improving the reliability of perovskite batteries in harsh environments.

[0036] 4. Optimize welding process and improve production efficiency: Using a thermally evaporated Cr / Cu composite layer as the welding area optimizes the welding process during the external electrode lead-out process. The temperature control requirements during the welding process are relatively low, production efficiency is higher, and battery damage caused by welding errors is reduced.

[0037] 5. Suitable for large-scale production and aerospace applications: The electrode lead-out method and structure of the present invention have good industrial production potential and can be used in large-scale perovskite battery production. It is particularly suitable for high-demand fields such as aerospace and satellites, and can ensure the high efficiency and stability of the battery during long-term use in extreme environments.

[0038] 6. Improve the commercial prospects of perovskite batteries: The electrode lead-out method and structure of the present invention provides an external electrode lead-out solution that can avoid high-temperature damage to the perovskite photoelectric layer, while enhancing the reliability of the welding joints, which helps to improve the reliability and stability of perovskite batteries in practical applications, thereby promoting the application of perovskite batteries in high-tech fields such as aerospace, and having a positive impact on their commercialization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a top view schematic diagram of the electrode lead-out structure of the perovskite battery for spacecraft of the present invention.

[0040] Figure 2 A side view schematic diagram of the invented perovskite battery electrode lead-out structure for spacecraft.

[0041] In the figure: 1-substrate; 2-P4 partition line; 3-laser edge cleaning area; 4-functional film layer; 5-back electrode layer; 61-battery positive electrode; 62-battery negative electrode; 71-positive electrode side edge P3 channel; 72-negative electrode side edge P2 channel; 81-positive electrode side Cr / Cu composite welding layer; 82-negative electrode side Cr / Cu composite welding layer; 91-positive electrode external metal electrode sheet; 92-negative electrode external metal electrode sheet; 10-welding connection. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to specific embodiments in conjunction with the accompanying drawings. It should be understood that these embodiments are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0043] It should be noted that the substrate 1 in the present invention is radiation-proof glass, and the substrate 1 used in the following embodiments is all cerium-doped radiation-proof glass.

[0044] See also Figure 1 、 Figure 2 The present invention provides a perovskite battery electrode lead-out structure for spacecraft, comprising:

[0045] The perovskite battery body has a battery positive electrode 61 and a battery negative electrode 62. The battery positive electrode 61 is defined by a P3 laser line forming a positive electrode side edge P3 channel 71, and the battery negative electrode 62 is defined by a P2 laser line forming a negative electrode side edge P2 channel 72. The edge area around the perovskite battery body is provided with a laser edge cleaning area 3. The functional film layer 4 and the back electrode layer 5 in the laser edge cleaning area 3 are completely removed to expose the substrate 1.

[0046] The Cr / Cu composite welding layer is arranged in the edge areas on both sides of the positive and negative electrodes of the perovskite battery body, including a Cr metal layer with a thickness of 5nm to 10nm directly contacting the substrate 1 and a Cu metal layer with a thickness of 110nm to 200nm covering the Cr metal layer; Cr is conducive to metal adhesion. The applicant found in the research that the provision of a 5nm to 10nm Cr metal layer can effectively enhance the adhesion between the external metal electrode sheet and the substrate without affecting the conductivity of the welding joint 10 (when the thickness of the Cr metal layer is less than 5nm, insufficient adhesion leads to evaporation welding failure of the Cu metal layer during welding; when the thickness of the Cr metal layer is greater than 10nm, not only will the welding cost and time be increased, but the conductivity of the welding joint 10 will also be reduced, resulting in a decrease in FF; when the thickness of the Cu metal layer is less than 110nm, the conductivity of the welding joint 10 is poor and the mechanical connectivity is poor (the Cu metal layer may fail in evaporation welding during welding), and the Cu metal layer is greater than 200nm, which will also increase the welding cost and time).

[0047] The positive electrode side Cr / Cu composite welding layer 81 completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, without exceeding the positive electrode side edge P3 channel 71; the negative electrode side Cr / Cu composite welding layer 82 completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, without exceeding the negative electrode side edge P2 channel 72. This arrangement can prevent the welding heat from affecting the functional layer when the external metal electrode sheet is welded to the Cr / Cu composite welding layer, and can also ensure the accuracy of electrode alignment.

[0048] The external metal electrode sheets include two positive external metal electrode sheets 91 welded to the upper surface of the positive electrode side Cr / Cu composite welding layer 81 and two negative external metal electrode sheets 92 welded to the upper surface of the negative electrode side Cr / Cu composite welding layer 82. The length of the contact portion between the external metal electrode sheet and the Cr / Cu composite welding layer is 2 to 3 mm and the area is 10 to 30 mm. 2 This arrangement can ensure the mechanical strength and electrical conductivity of the welding joint 10.

[0049] The present invention is further configured such that the width of the laser edge cleaning area 3 is 3.5 mm to 3.8 mm.

[0050] The present invention is further configured such that the length of the Cr / Cu composite welding layer is 30 to 40 mm, and the width is 4 to 4.5 mm.

[0051] The present invention is further configured such that the distance between the two positive external metal electrode sheets 91 is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets 92 is 6 mm to 10 mm.

[0052] The present invention is further configured such that the material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

[0053] The present invention is further configured such that the back electrode layer 5 is made of gold, silver, copper or aluminum, and has a thickness of 100 to 200 nm.

[0054] Continue to see Figure 1 、 Figure 2 The present invention also provides a method for extracting electrodes of a perovskite battery for a spacecraft, comprising the following steps:

[0055] S0. Forming the positive and negative electrode structures of the perovskite battery: forming a positive electrode side edge P3 channel 71 on the perovskite battery body by P3 laser scribing to define the battery positive electrode 61; forming a negative electrode side edge P2 channel 72 by P2 laser scribing to define the battery negative electrode 62;

[0056] S1. Laser edge cleaning: Use laser to perform P4 edge cleaning on the perovskite cell, removing all functional film layers 4 and back electrode layers 5 around the edge until the substrate 1 is exposed, forming a laser edge cleaning area 3; the width of the P4 edge cleaning is 3.5mm to 3.8mm;

[0057] S2. Preparation of Cr / Cu composite welding layer: In the edge area of ​​the positive and negative electrodes of the perovskite battery treated by P4 laser edge cleaning, first use the thermal evaporation method to The Cr metal layer with a thickness of 5 to 10 nm is evaporated at a rate of The Cr metal layer is covered with a Cu metal layer having a thickness of 110 to 200 nm at a deposition rate to form a Cr / Cu composite welding layer as the welding area; when a 5 to 10 nm Cr metal layer is prepared by thermal evaporation, The evaporation rate can ensure the distribution consistency of the thickness, density and composition of the evaporated Cr metal layer, and has strong adhesion, which is conducive to welding. Too low or too high evaporation rate will lead to uneven Cr metal layer, which will cause welding failure. When using thermal evaporation to prepare 110-200nm Cu metal layer, The evaporation rate can ensure the distribution consistency of the thickness, density and composition of the evaporated Cu metal layer, which is not easily evaporated by the high temperature of welding, and the conductivity and mechanical strength of the welding joint 10 are good; if the evaporation rate is too low or too high, the Cu metal layer will be uneven, which will also cause welding failure.

[0058] The positive electrode side Cr / Cu composite welding layer 81 completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, and does not exceed the positive electrode side edge P3 channel 71; the negative electrode side Cr / Cu composite welding layer 82 completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, and does not exceed the negative electrode side edge P2 channel 72;

[0059] S3. Welding of external metal electrode sheets: Two external metal electrode sheets are welded to the upper surface of the Cr / Cu composite welding layer 81 on the positive electrode side and the upper surface of the Cr / Cu composite welding layer 82 on the negative electrode side, respectively, at a welding temperature of 300-350°C and a welding time of 5-10s. Here, the welding temperature is controlled to be 300-350°C and the welding time is 5-10s. In the presence of the Cr / Cu composite welding layer, a firm connection and good conductivity between the external metal electrode sheet and the Cr / Cu composite welding layer are ensured without damaging the perovskite functional layer. The length of the contact portion between the external metal electrode sheet and the Cr / Cu composite welding layer is 2-3mm, and the area is 10-30mm. 2 .

[0060] Furthermore, in step S2, the length of the Cr / Cu composite welding layer is 30-40 mm, and the width is 4-4.5 mm.

[0061] Furthermore, in step S3 , the distance between the two positive external metal electrode sheets 91 is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets 92 is 6 mm to 10 mm.

[0062] Furthermore, in step S3, the material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

[0063] Furthermore, in step S3, the welding method is laser welding or soldering.

[0064] Example 1

[0065] The preparation of the perovskite solar cell assembly of this embodiment includes the following steps:

[0066] (1) Pretreatment of substrate 1: A cerium-doped borosilicate glass with a thickness of 0.1 mm and a size of 50 mm*50 mm was selected as substrate 1. The substrate 1 was sequentially ultrasonically cleaned (ethanol / deionized water, each for 10 min), and then treated with plasma or UV-ozone for 10 min;

[0067] (2) Preparation of transparent conductive layer: Indium tin oxide (ITO) with a thickness of 150 nm was deposited on the upper surface of the pretreated substrate 1 by magnetron sputtering as a transparent conductive layer;

[0068] (3) P1 laser scribing: Use a green laser with a wavelength of 532nm to scribble P1 lines, forming multiple evenly spaced P1 trenches with a width of 5μm, separating the transparent conductive layer to form independent bottom electrode strips;

[0069] (4) Preparation of functional film layer 4: On the upper surface of the transparent conductive layer after laser-scribing the P1 channel, a hole transport layer, a perovskite functional layer, and an electron transport layer are sequentially prepared from bottom to top by electron beam evaporation process; wherein the hole transport layer is NiO with a thickness of 10 nm; the perovskite functional layer is mainly composed of FACsPbI with a thickness of 400 nm; and the electron transport layer is SnO2 with a thickness of 20 nm;

[0070] (5) P2 laser scribing: After the deposition of the functional film layer 4 is completed, a green laser with a wavelength of 532 nm is used to perform P2 scribing to form multiple P2 trenches with a width of 30 μm. The hole transport layer, perovskite functional layer, and electron transport layer in the P2 trench are removed to expose the transparent conductive layer for electrode connection. The P2 trench is located on one side of the P1 trench and maintains a 5 μm interval with it.

[0071] (6) Preparation of the back electrode layer 5: Using thermal evaporation, a Cu layer with a thickness of 100 nm is deposited on the top layer of the device as the back electrode layer 5 to form the perovskite cell body;

[0072] (7) P3 laser scribing: After the deposition of the back electrode layer 5 is completed, a green laser with a wavelength of 532nm is used to perform P3 scribing to form multiple P3 channels with a width of 20um, separating the hole transport layer, perovskite layer, electron transport layer and back electrode layer 5 to avoid short circuit; the P3 channel is located on one side of the P2 channel and maintains a spacing of 5um therebetween; the P2 channel is located between the P1 channel and the P3 channel; wherein, one side edge of the battery is normally subjected to P3 laser scribing to form the positive side edge P3 channel 71, which becomes the positive electrode 61 of the battery; the other side edge is not subjected to P3 laser scribing, and the negative side edge P2 channel 72 formed by the P2 laser scribing on this side becomes the negative electrode 62 of the battery;

[0073] (8) Laser edge cleaning (formation of P4 partition line 2): The device obtained in step (7) is subjected to P4 edge cleaning using a green laser with a wavelength of 532 nm to remove all functional film layers 4 and back electrode layers 5 in the peripheral edge region until the substrate 1 is exposed, forming a laser edge cleaning region 3; the width of the P4 edge cleaning is 3.8 mm; the obtained device is denoted as D1;

[0074] (9) Preparation of Cr / Cu composite welding layer: In the edge area of ​​the positive and negative electrodes of the device treated by P4 laser edge cleaning, first use the thermal evaporation method to The Cr metal layer with a thickness of 5nm was evaporated at a deposition rate of A Cu metal layer with a thickness of 150 nm is deposited at a deposition rate of 100 nm to cover the Cr metal layer, forming a Cr / Cu composite welding layer. The length of the Cr / Cu composite welding layer is 35 mm and the width is 4.5 mm. The positive electrode side Cr / Cu composite welding layer 81 completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, without exceeding the positive electrode side edge P3 channel 71. The negative electrode side Cr / Cu composite welding layer 82 completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, without exceeding the negative electrode side edge P2 channel 72. The resulting device is denoted as X1.

[0075] (10) External metal electrode sheet welding: Using soldering technology, the welding temperature is 350℃, and the welding time is 5s. Two Kovar metal electrode sheets are welded on the upper surface of the Cr / Cu composite welding layer 81 on the positive side of the device X1 and the upper surface of the Cr / Cu composite welding layer 82 on the negative side. The width of the Kovar metal electrode sheet is 6mm, the length is 20mm, and the length of the part in contact with the Cr / Cu composite welding layer is 2mm, and the area is 12mm. 2 ; The obtained device is recorded as Y1;

[0076] (11) Battery packaging: Device Y1 is packaged to protect it from the external environment. The packaging structure includes the device, POE film, butyl rubber, and cover plate in sequence. The POE (polyolefin elastomer) film is 0.2 mm thick. The butyl rubber is 0.4 mm thick and 3 mm wide. The cover plate is made of borosilicate glass with a thickness of 100 μm. A laminator is used to bond the packaging structure, so that the film and edge sealant are melted and solidified to ensure that the cover plate and battery cell are tightly bonded. The lamination pressure is 70 kPa, the temperature is 115°C, and the pressing time is 20 min. The resulting device is recorded as W1.

[0077] Example 2

[0078] The perovskite solar cell assembly of this embodiment is prepared according to the method of Example 1, except that:

[0079] The device prepared after steps (1) to (8) is denoted as D2;

[0080] Preparation of the Cr / Cu composite welding layer in step (9): the thickness of the Cr metal layer is 5 nm, and the thickness of the Cu metal layer is 200 nm; the device obtained in step (9) is denoted as X2;

[0081] According to step (10) in Example 1, the Kovar metal electrode sheet was welded to the upper surface of the Cr / Cu composite welding layer of the device X2, and the obtained device was recorded as Y2;

[0082] Device Y3 and device Y4 are packaged according to step (11) in Example 1, and the obtained device is recorded as W2.

[0083] Example 3

[0084] The perovskite solar cell assembly of this embodiment is prepared according to the method of Example 1, except that:

[0085] The device prepared after steps (1) to (8) is denoted as D3;

[0086] Preparation of the Cr / Cu composite welding layer in step (9): the thickness of the Cr metal layer is 10 nm, and the thickness of the Cu metal layer is 110 nm; the device obtained in step (9) is denoted as X3;

[0087] According to step (10) in Example 1, the Kovar metal electrode sheet was welded to the upper surface of the Cr / Cu composite welding layer of the device X3, and the obtained device was recorded as Y3;

[0088] Device Y3 is packaged according to step (11) in Example 1, and the obtained device is denoted as W3.

[0089] Example 4

[0090] The perovskite solar cell assembly of this embodiment is prepared according to the method of Example 1, except that:

[0091] The device prepared after steps (1) to (8) is denoted as D4;

[0092] Preparation of the Cr / Cu composite welding layer in step (9): the thickness of the Cr metal layer is 10 nm, and the thickness of the Cu metal layer is 200 nm; the device obtained in step (9) is denoted as X4;

[0093] According to step (10) in Example 1, the Kovar metal electrode sheet was welded to the upper surface of the Cr / Cu composite welding layer of the device X4, and the obtained device was recorded as Y4;

[0094] Device Y4 is packaged according to step (11) in Example 1, and the obtained device is recorded as W4.

[0095] Example 5

[0096] The perovskite solar cell assembly of this embodiment is prepared according to the method of Example 1, except that:

[0097] The device prepared after steps (1) to (8) is denoted as D5;

[0098] Preparation of Cr / Cu composite welding layer in step (9): The thickness of Cr metal layer is 10nm, and the evaporation rate is The thickness of the Cu metal layer is 200 nm, and the evaporation rate is The device obtained in step (9) is denoted as X5;

[0099] According to step (10) of Example 1, the Kovar metal electrode sheet is welded to the upper surface of the Cr / Cu composite welding layer of the device X5, except that the width of the Kovar metal electrode sheet is 8 mm, the length is 20 mm, the length of the portion in contact with the Cr / Cu composite welding layer is 3 mm, and the area is 24 mm. 2 ; The obtained device is recorded as Y5;

[0100] Device Y5 is packaged according to step (11) in Example 1, and the obtained device is recorded as W5.

[0101] Example 6

[0102] The perovskite solar cell assembly of this embodiment is prepared according to the method of Example 1, except that:

[0103] The device prepared after steps (1) to (8) is denoted as D6;

[0104] Preparation of Cr / Cu composite welding layer in step (9): The thickness of Cr metal layer is 10nm, and the evaporation rate is The thickness of the Cu metal layer is 200 nm, and the evaporation rate is The device obtained in step (9) is denoted as X6;

[0105] According to step (10) of Example 1, the Kovar metal electrode sheet is welded to the upper surface of the Cr / Cu composite welding layer of the device X6, except that the width of the Kovar metal electrode sheet is 8 mm, the length is 20 mm, the length of the portion in contact with the Cr / Cu composite welding layer is 3 mm, and the area is 24 mm. 2 ; The obtained device is recorded as Y6;

[0106] Device Y6 was packaged according to step (11) in Example 1, and the obtained device was denoted as W6.

[0107] Comparative Example 1

[0108] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0109] The device prepared after steps (1) to (8) is denoted as A1;

[0110] There is no step (9), that is, no Cr / Cu composite welding layer is prepared:

[0111] In step (10), soldering technology is used, the soldering temperature is 350°C, the soldering time is 5s, and two Kovar metal electrode sheets are directly soldered on the upper surface of the back electrode layer at the positive side edge and the upper surface of the back electrode layer at the negative side edge of device A1; the width of the Kovar metal electrode sheet is 6mm, the length is 20mm, the length of the part in contact with the back electrode layer is 2mm, and the area is 12mm. 2 ; The obtained device is recorded as C1;

[0112] During the welding process, the metal Cu of the back electrode layer 5 is directly evaporated by the high welding temperature, and welding cannot be achieved.

[0113] Comparative Example 2

[0114] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0115] The device prepared after steps (1) to (8) is denoted as A2;

[0116] In step (9), the edge areas of the positive and negative electrodes of the perovskite battery treated by P4 laser edge cleaning are only treated by thermal evaporation. A Cu metal layer with a thickness of 150 nm was evaporated at an evaporation rate (no Cr metal layer was prepared, and the Cu metal layer directly contacted the substrate 1), and the obtained device was recorded as B2;

[0117] In step (10), soldering technology is used, with a soldering temperature of 350° C. and a soldering time of 5 seconds, to solder two Kovar metal electrode sheets to the upper surface of the Cu metal layer on the positive electrode side and the upper surface of the Cu metal layer on the negative electrode side of device A2, respectively;

[0118] During the welding process, the Cu metal layer directly contacting the substrate 1 at the welding joint evaporates, resulting in welding failure.

[0119] Comparative Example 3

[0120] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0121] The device prepared after steps (1) to (8) is denoted as A3;

[0122] Preparation of the Cr / Cu composite welding layer in step (9): The thickness of the Cr metal layer prepared by thermal evaporation is 4 nm, and the obtained device is denoted as B3;

[0123] In step (10), soldering technology is used at a soldering temperature of 350° C. and a soldering time of 5 seconds to solder two Kovar metal electrode sheets to the upper surface of the Cr / Cu composite soldering layer 81 on the positive side and the upper surface of the Cr / Cu composite soldering layer 82 on the negative side of the device A3, respectively.

[0124] During the welding process, due to insufficient adhesion, the Cu metal layer at the welding joint evaporates, resulting in welding failure.

[0125] Comparative Example 4

[0126] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0127] The device prepared after steps (1) to (8) is denoted as A4;

[0128] Preparation of Cr / Cu composite welding layer in step (9): The evaporation rate of the Cr metal layer prepared by thermal evaporation is The obtained device is denoted as B4;

[0129] In step (10), soldering technology is used at a soldering temperature of 350° C. and a soldering time of 5 seconds to solder two Kovar metal electrode sheets to the upper surface of the Cr / Cu composite soldering layer 81 on the positive side and the upper surface of the Cr / Cu composite soldering layer 82 on the negative side of the device A4, respectively.

[0130] During the welding process, due to insufficient adhesion, the Cu metal layer at the welding joint evaporates, resulting in welding failure.

[0131] Comparative Example 5

[0132] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0133] The device prepared after steps (1) to (8) is denoted as A5;

[0134] Preparation of Cr / Cu composite welding layer in step (9): The evaporation rate of the Cr metal layer prepared by thermal evaporation is The obtained device is denoted as B5;

[0135] In step (10), soldering technology is used at a soldering temperature of 350° C. and a soldering time of 5 seconds to solder two Kovar metal electrode sheets to the upper surface of the Cr / Cu composite soldering layer 81 on the positive side and the upper surface of the Cr / Cu composite soldering layer 82 on the negative side of the device A5, respectively.

[0136] During the welding process, due to insufficient adhesion, the Cu metal layer at the welding joint evaporates, resulting in welding failure.

[0137] Comparative Example 6

[0138] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0139] The device prepared after steps (1) to (8) is denoted as A6;

[0140] Preparation of the Cr / Cu composite welding layer in step (9): The thickness of the Cr metal layer was 12 nm by thermal evaporation, and the obtained device was designated as B6;

[0141] In step (10), soldering technology is used at a soldering temperature of 350° C. for a soldering time of 5 seconds to solder two Kovar metal electrode sheets to the upper surface of the Cr / Cu composite soldering layer 81 on the positive side and the upper surface of the Cr / Cu composite soldering layer 82 on the negative side of the device A6. The resulting device is designated C6.

[0142] Device C6 was packaged according to step (11) in Example 1, and the obtained device was denoted as Z6.

[0143] Comparative Example 7

[0144] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0145] The device prepared after steps (1) to (8) is denoted as A7;

[0146] Preparation of the Cr / Cu composite welding layer in step (9): The Cu metal layer was prepared by thermal evaporation to a thickness of 100 nm. The obtained device was designated as B7.

[0147] In step (10), soldering technology is used at a soldering temperature of 350° C. for a soldering time of 5 seconds to solder two Kovar metal electrode sheets to the upper surface of the Cr / Cu composite soldering layer 81 on the positive side and the upper surface of the Cr / Cu composite soldering layer 82 on the negative side of the device A6. The resulting device is designated C7.

[0148] Device C7 was packaged according to step (11) in Example 1, and the obtained device was denoted as Z7.

[0149] Comparative Example 8

[0150] The perovskite solar cell assembly of this comparative example was prepared according to the method of Example 1, except that:

[0151] The device prepared after steps (1) to (8) is denoted as A8;

[0152] There is no step (9); the electrode lead-out method is to directly stick two pieces of Kovar metal electrode sheets on the upper surface of the back electrode layer at the positive side edge and the upper surface of the back electrode layer at the negative side edge of the device A8 through a conductive copper tape with a width of 6 mm and a length of 20 mm; the Kovar metal electrode sheet has a width of 6 mm and a length of 20 mm, the length of the part in contact with the back electrode layer is 2 mm, and the area is 12 mm 2 ; The obtained device is recorded as C8;

[0153] Device C8 was packaged according to step (11) in Example 1, and the obtained device was denoted as Z8.

[0154] In the above embodiments and comparative examples, in comparative example 1, during the welding process, the metal Cu of the back electrode layer 5 is directly evaporated by the high temperature of welding, and welding cannot be achieved, indicating that the use of direct welding will not only cause the failure of the battery perovskite functional layer due to the high welding temperature, but also cause the battery to be completely damaged and unable to work after welding, and the welding heat will also cause the metal of the back electrode layer to evaporate, making welding impossible; in comparative example 2 (no Cr layer), the Cu layer fails to evaporate during welding, proving the necessity of the Cr metal layer for adhesion; comparative examples 3 to 5 (Cr metal layer <5nm or the evaporation rate is too high or too low) all fail to weld due to insufficient adhesion, proving that the thickness of the Cr metal layer is ≥5nm and the evaporation rate of the Cr metal layer prepared by thermal evaporation is controlled at Necessity within.

[0155] A standard solar simulator (AM 1.5G, 100mW / cm 2) Perform IV tests on devices X1 to X6, Y1 to Y6, B6 to B8, and C6 to C8, and record their open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), and PCE as shown in Table 1; the test steps are as follows:

[0156] 1) Test equipment: Use a calibrated solar cell IV test system, including a Class AAA solar light source, a standard reference cell, and a Keithley 2400 precision source meter.

[0157] 2) Test conditions: Light intensity is 100mW / cm 2 , the test environment temperature is controlled at 23℃ to avoid temperature interference with battery performance;

[0158] Table 1. IV test results of devices D1-D6, Y1-Y6, A6-A8, and C6-C8

[0159] Device Voc(V) <![CDATA[Jsc(mA·cm -2 )]]> FF(%) PCE (%) D1 9.006 45.56 81.25 20.84 Y1 9.260 45.82 81.11 21.51 D2 9.238 46.01 78.15 20.76 Y2 9.061 45.83 80.80 20.97 D3 9.037 45.62 77.62 20.00 Y3 9.228 46.09 77.70 20.65 D4 9.225 46.43 77.00 20.61 Y4 9.026 46.24 79.58 20.76 D5 9.032 45.86 79.64 20.62 Y5 9.185 45.74 77.47 20.34 D6 9.006 45.84 80.10 20.67 Y6 9.222 46.24 79.42 21.16 A6 8.870 45.95 74.86 19.07 C6 8.240 45.16 66.66 15.50 A7 9.176 46.24 80.08 21.23 C7 8.591 44 69.70 16.45 A8 9.109 45.85 80.64 21.05 C8 9.274 45.90 79.14 21.06

[0160] Analyzing the data in Table 1, it can be seen that the PCE attenuation of Y1 to Y6 after welding (300-350°C) is all <0.3% (such as Y1: 20.84%→21.51%), which proves that the Cr / Cu composite welding layer (Cr: 5-10nm, Cu: 110-200nm) can effectively block heat conduction and prevent high temperature from damaging the perovskite functional layer; in Comparative Example 6, the thickness of the Cr metal layer is 12nm>10nm. Although the Cr / Cu composite welding layer in this comparative example can effectively block heat conduction, it will cause the conductivity of the welding joint to deteriorate significantly (FF is significantly reduced), which in turn leads to a significant decrease in the photoelectric conversion efficiency of the battery; in Comparative Example 7, the thickness of the Cu metal layer is 100nm<110nm. Although the welding is successful, the conductivity of the welding joint is poor, which leads to a significant decrease in the photoelectric conversion efficiency of the battery.

[0161] A standard push-pull tester was used to perform tensile tests on the welding joints of Y1 to Y6 and C6 to C8. The results are shown in Table 2. The test process is as follows:

[0162] 1) Test equipment: Use an electronic tensile testing machine equipped with a micro-force clamp, with a tensile resolution of not less than 0.1N and a clamping error of less than ±0.2mm;

[0163] 2) Sample preparation: After the device is cooled to room temperature after welding and the weld metal is completely solidified, the free end of the Kovar metal electrode is connected to the upper tension fixture and the lower tension fixture is connected to the battery cell itself.

[0164] 3) Test conditions:

[0165] A: The stretching direction is perpendicular to the welding surface;

[0166] B: The stretching speed is set to 5 mm / min;

[0167] C: Automatically stop at the breaking point and record the peak tensile force.

[0168] Table 2. Tensile test results of devices Y1 to Y6, C6 to C8

[0169] Device Welding joint 1 Welding joint 2 Welding joint 3 Welding joint 4 Y1 40.3 40.6 40.5 40.7 Y2 40.5 40.1 40.6 40.2 Y3 41.8 41.6 41.9 41.5 Y4 41.2 40.9 41.3 41.1 Y5 42.9 42.1 42.6 42.4 Y6 42.8 42.9 42.3 42.4 C6 43.5 43.2 43.7 43.4 C7 28.4 27.9 32.1 29.2 C8 5.2 5.1 4.9 4.8

[0170] Analyzing the data in Table 2, it can be seen that the tensile force of the Y1~Y6 welds is stable>40N (such as Y1:40.3~40.7N), which far exceeds the spacecraft requirement of>30N and is more than doubled compared with the traditional process (<15N). This shows that the Cr / Cu composite welding layer can effectively enhance the strength of the welded joints, and the increase in the thickness of the Cr metal layer in the Cr / Cu composite welding layer or the increase in the welding joint area (the contact area between the Kovar metal electrode sheet and the Cr / Cu composite welding layer) can improve the strength of the welded joints; in Example 6, the Cr metal layer The thickness of the Cu metal layer is 12nm. Although it can ensure the mechanical strength of the welding joints, it will cause the conductivity of the welding joints to decrease and the battery performance to deteriorate; in Comparative Example 7, the thickness of the Cu metal layer is 100nm<110nm. Although the welding is successful, the mechanical strength of the welding joints is unstable and it is difficult to meet the requirements of spacecraft; in Comparative Example 8, conductive copper tape is used to directly stick the Kovar metal electrode sheet to the back electrode layer. Although it can ensure conductivity and battery efficiency, the average tensile strength of the bonding joints is only 5N, which cannot meet the requirements of >30N for spacecraft.

[0171] Refer to GJB 322A-2009 standard for W1~W6 and Z6~Z8 (500 temperature cycles (-90℃~100℃)), the test results are shown in Table 3.

[0172] Table 3. High and low temperature test results of devices W1 to W6 and Z6 to Z8

[0173]

[0174] Refer to GJB3758-99 standard for W1~W6 and Z6~Z8 (200h thermal vacuum temperature (100℃, ≤1.3*10 - 3 Pa), test results are shown in Table 4 and Table 5.

[0175] Table 4. Thermal vacuum test PCE results of devices W1 to W6 and Z6 to Z8

[0176] Device / H / % 0 50 100 150 200 W1 20.49 20.34 20.19 20.08 19.91 W2 20.81 20.66 20.51 20.39 20.09 W3 20.43 20.28 20.13 20.11 19.86 W4 20.69 20.54 20.39 20.17 20.04 W5 20.19 20.04 19.89 19.77 19.68 W6 20.51 20.36 20.21 20.19 19.72 Z6 15.01 14.94 14.85 14.78 14.66 Z7 15.97 15.89 15.8 15.72 15.61 Z8 4.05 3.88 3.81 3.76 3.75

[0177] Table 5. Tensile strength results of devices W1-W6 and Z6-Z8 after thermal vacuum test (after 200h)

[0178] Device Welding joint 1 Welding joint 2 Welding joint 3 Welding joint 4 W1 40.2 40.5 40.4 40.6 W2 40.6 40.2 40.5 40.1 W3 41.7 41.5 41.8 41.6 W4 41.3 40.7 41.5 41.2 W5 42.8 42.3 42.4 42.5 W6 42.7 42.8 42.4 42.3 Z6 43.2 43.1 43.5 43.1 Z7 26.1 27.5 31.8 28.7 Z8 4.9 4.5 4.2 4.6

[0179] It can be seen from the data in Tables 3 to 5 that compared with Z6 to Z8, W1 to W6 containing the electrode lead-out structure of the present invention performed well during the high and low temperature cycle test and the thermal vacuum test, with a PCE decay of less than 5%. After the thermal vacuum test, the solder joint tension remained above 40N, indicating that the electrode lead-out structure and method of the present invention can effectively enhance the stability of the perovskite battery in extreme aerospace environments. The perovskite battery containing this structure can work for a long time under high and low temperature cycles and vacuum conditions, significantly improving the reliability of the perovskite battery in harsh environments.

[0180] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A perovskite battery electrode lead-out structure for spacecraft, characterized in that: include: The perovskite battery body has a positive electrode and a negative electrode. The positive electrode is defined by a P3 channel formed by P3 laser scribing, and the negative electrode is defined by a P2 channel formed by P2 laser scribing. The edge area around the perovskite battery body is provided with a laser edge cleaning zone, and the back electrode layer and functional film layer in the laser edge cleaning zone are completely removed to expose the substrate. A Cr / Cu composite welding layer is provided at the edge areas of the positive and negative electrodes of the perovskite battery body, comprising a Cr metal layer with a thickness of 5nm to 10nm directly contacting the substrate and a Cu metal layer with a thickness of 110nm to 200nm covering the Cr metal layer; The positive electrode side Cr / Cu composite welding layer completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, and does not exceed the positive electrode side edge P3 channel; the negative electrode side Cr / Cu composite welding layer completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, and does not exceed the negative electrode side edge P2 channel; External metal electrode sheets, including two positive external metal electrode sheets welded on the upper surface of the Cr / Cu composite welding layer on the positive side and two negative external metal electrode sheets welded on the upper surface of the Cr / Cu composite welding layer on the negative side. The length of the contact part between the external metal electrode sheets and the Cr / Cu composite welding layer is 2 to 3 mm, and the area is 10 to 30 mm. 2 .

2. The electrode lead-out structure according to claim 1, characterized in that: The width of the laser edge cleaning area is 3.5 mm to 3.8 mm.

3. The electrode lead-out structure according to claim 1, wherein: The Cr / Cu composite welding layer has a length of 30 to 40 mm and a width of 4 to 4.5 mm.

4. The electrode lead-out structure according to claim 1, wherein: The distance between the two positive external metal electrode sheets is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets is 6 mm to 10 mm.

5. The electrode lead-out structure according to claim 1, characterized in that: The material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

6. The electrode lead-out structure according to claim 1, wherein: The back electrode layer is made of gold, silver, copper or aluminum, and has a thickness of 100 to 200 nm.

7. A method for extracting electrodes of a perovskite battery for spacecraft, characterized in that: The following steps are involved: S0. Forming the positive and negative electrode structures of the perovskite battery: forming a P3 channel on the positive electrode side edge on the perovskite battery body by P3 laser scribing to define the positive electrode of the battery; forming a P2 channel on the negative electrode side edge by P2 laser scribing to define the negative electrode of the battery; S1. Laser edge cleaning: Use laser to perform P4 edge cleaning on the perovskite cell, removing all back electrode layers and functional film layers around the edge until the substrate is exposed, forming a laser edge cleaning area; S2. Preparation of a Cr / Cu composite welding layer: On the edge areas of the positive and negative electrodes of the perovskite cell that have been treated with P4 laser edge cleaning, a 5-10 nm thick Cr metal layer is first prepared. Then, a 110-200 nm thick Cu metal layer is prepared to cover the Cr metal layer, forming a Cr / Cu composite welding layer as the welding area. The positive electrode side Cr / Cu composite welding layer completely covers the positive electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the positive electrode side back electrode layer, and does not exceed the positive electrode side edge P3 channel; the negative electrode side Cr / Cu composite welding layer completely covers the negative electrode side laser edge cleaning area along its width direction and extends to cover the edge area of ​​the negative electrode side back electrode layer, and does not exceed the negative electrode side edge P2 channel; S3. External metal electrode sheet welding: Weld two external metal electrode sheets to the upper surface of the Cr / Cu composite welding layer on the positive side and the upper surface of the Cr / Cu composite welding layer on the negative side respectively. The welding temperature is 300-350°C and the welding time is 5-10s. The length of the contact part between the external metal electrode sheet and the Cr / Cu composite welding layer is 2-3mm and the area is 10-30mm. 2 .

8. The electrode extraction method according to claim 7, characterized in that: In step S1, the width of the edge clearing P4 is 3.5 mm to 3.8 mm.

9. The electrode extraction method according to claim 7, characterized in that: In step S2, the Cr / Cu composite welding layer is prepared by thermal evaporation method, and the evaporation rate of the Cr metal layer is Cu metal layer evaporation rate 10. The electrode extraction method according to claim 7, characterized in that: In step S2, the length of the Cr / Cu composite welding layer is 30-40 mm, and the width is 4-4.5 mm.

11. The electrode extraction method according to claim 7, characterized in that: In step S3, the distance between the two positive external metal electrode sheets is 16 mm to 22 mm, and the distance between the two negative external metal electrode sheets is 6 mm to 10 mm.

12. The electrode extraction method according to claim 7, characterized in that: In step S3, the material of the external metal electrode sheet is aluminum alloy, copper alloy or Kovar alloy.

13. The electrode extraction method according to claim 7, characterized in that: In step S3, the welding method is laser welding or soldering.

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