Battery structure and fabrication methods, battery modules and photovoltaic systems

Abstract

This invention discloses a battery structure and its fabrication method, a battery module, and a photovoltaic system. The battery structure includes: a substrate, and a plurality of first doped regions and a plurality of second doped regions disposed on a first side of the substrate; the first doped regions and the second doped regions are arranged alternately; an isolation groove is disposed on the substrate between adjacent first doped regions and second doped regions, the isolation groove including a first part and a second part, the sidewall of the first part being a first sidewall, and the sidewall of the second part being a second sidewall; a first angle between the first sidewall and a horizontal line is less than or greater than a second angle between the second sidewall and the horizontal line; wherein the extension direction of the horizontal line is perpendicular to the depth direction of the isolation groove. This invention can make the battery structure more stress-resistant and more reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery structure and a preparation method, a battery assembly and a photovoltaic system. BACKGROUND

[0002] Solar cells are a kind of photoelectric semiconductor thin sheets that directly generate electricity by using sunlight, also known as "solar chips" or "photocells", which can output voltage and generate current in a loop under the condition of light illumination meeting certain illumination conditions.

[0003] In the related art, in order to prevent the first doped region and the second doped region from being conductive and leaking, the first doped region and the second doped region are usually isolated by an isolation groove. In the related art, after the isolation groove is prepared, the battery has the risk of hidden cracks, poor stress resistance, and affects the reliability of the battery. SUMMARY

[0004] The present application provides a battery structure and a preparation method, a battery assembly and a photovoltaic system, which can make the stress resistance of the battery structure stronger and the reliability higher.

[0005] According to an aspect of the present application, a battery structure is provided, comprising:

[0006] a substrate, and a plurality of first doped regions and a plurality of second doped regions arranged on a first side of the substrate; the first doped regions and the second doped regions are arranged alternately;

[0007] The substrate between adjacent first doped regions and second doped regions is provided with an isolation groove, and the isolation groove comprises a first part and a second part, the side wall of the first part is a first side wall, and the side wall of the second part is a second side wall;

[0008] The first included angle between the first side wall and the horizontal line is smaller or larger than the second included angle between the second side wall and the horizontal line; wherein the extension direction of the horizontal line is perpendicular to the depth direction of the isolation groove.

[0009] On the basis of the above-mentioned embodiments, optionally, the range of the first included angle is greater than 0 degrees and less than 180 degrees; and / or, the range of the second included angle is greater than 0 degrees and less than 180 degrees.

[0010] On the basis of the above-mentioned embodiments, optionally, the first side wall is an inclined side wall, and / or the second side wall is an inclined side wall.

[0011] On the basis of the above-mentioned embodiments, optionally, the range of the first included angle is greater than 0 degrees and less than or equal to 90 degrees; and / or, the range of the second included angle is greater than or equal to 90 degrees and less than 180 degrees.

[0012] On the basis of the above-mentioned embodiments, optionally, the first included angle ranges from greater than or equal to 90 degrees to less than 180 degrees; and / or, the second included angle ranges from greater than 0 degrees to less than or equal to 90 degrees.

[0013] On the basis of the above-mentioned embodiments, optionally, the first included angle ranges from greater than or equal to 90 degrees to less than 180 degrees; and / or, the second included angle ranges from greater than or equal to 90 degrees to less than 180 degrees.

[0014] On the basis of the above-mentioned embodiments, optionally, the first side wall comprises a first sub-wall and a second sub-wall, and the first sub-wall and the second sub-wall each comprise a first end and a second end; the second side wall comprises a third sub-wall and a fourth sub-wall, and the first sub-wall and the second sub-wall each comprise a third end and a fourth end; the second end of the first sub-wall and the third end of the third sub-wall are in contact to form a first common end point, and the second end of the second sub-wall and the third end of the fourth sub-wall are in contact to form a second common end point.

[0015] The line connecting the first end of the first sub-wall and the first end of the second sub-wall is a first connecting line; the line connecting the first common end point and the second common end point is a second connecting line, and the second connecting line divides the isolation groove into a first part and a second part; the line connecting the fourth end of the third sub-wall and the fourth end of the fourth sub-wall is a third connecting line.

[0016] The length of the second connecting line is greater than the length of the first connecting line or the length of the third connecting line; or, the length of the first connecting line is greater than the length of the second connecting line or the length of the third connecting line; or, the length of the third connecting line is greater than the length of the second connecting line or the length of the first connecting line.

[0017] On the basis of the above-mentioned embodiments, optionally, the length of the first connecting line ranges from 20 microns to 250 microns; the length of the second connecting line ranges from 20 microns to 250 microns; and / or, the length of the third connecting line ranges from 20 microns to 250 microns.

[0018] On the basis of the above-mentioned embodiments, optionally, the length of the first sub-wall is the same as or different from the length of the second sub-wall, and / or the length of the third sub-wall is the same as or different from the length of the fourth sub-wall.

[0019] On the basis of the above-mentioned embodiments, optionally, the length of the first sub-wall ranges from 10 nanometers to 500 nanometers, and the length of the second sub-wall ranges from 10 nanometers to 500 nanometers.

[0020] The length of the third sub-wall ranges from 0.5 microns to 10 microns, and the length of the fourth sub-wall ranges from 0.5 microns to 10 microns.

[0021] On the basis of the above-mentioned embodiments, optionally, the length of the first side wall is the same as or different from the length of the second side wall.

[0022] Based on the above embodiments, optionally, the length of the first sidewall ranges from 10 nanometers to 500 nanometers; and the length of the second sidewall ranges from 0.5 micrometers to 10 micrometers.

[0023] Based on the above embodiments, optionally, both the first doped region and the plurality of second doped regions include extensions, and the extensions all extend toward the isolation trench;

[0024] The extension is located above the isolation groove.

[0025] Based on the above embodiments, optionally, the length of the extension in the first direction ranges from 0.1 micrometer to 1 micrometer, and the thickness of the extension in the second direction ranges from 10 nanometers to 500 nanometers.

[0026] According to another aspect of the present invention, a method for preparing a battery structure is provided, comprising:

[0027] Provide a base;

[0028] Multiple first doped regions and multiple second doped regions are formed on the first side of the substrate;

[0029] An isolation trench is formed on a substrate between adjacent first and second doped regions. The isolation trench includes a first part and a second part, the sidewall of the first part is a first sidewall, and the sidewall of the second part is a second sidewall. The first angle between the first sidewall and the horizontal line is less than or greater than the second angle between the second sidewall and the horizontal line. The horizontal line extends in a direction perpendicular to the depth direction of the isolation trench.

[0030] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including:

[0031] An isolation trench is formed between adjacent first and second doped regions using an alkaline etching process.

[0032] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including:

[0033] Under the conditions of an alkaline solution mass ratio of 0.5%-10%, an additive volume fraction of 0.1%-5%, a temperature of 40℃-95℃, and a treatment time of 300s-1500s, an isolation groove is formed between adjacent first and second doped regions, such that the first included angle is smaller than the second included angle; wherein, the additive includes any one of surfactants, dispersants, and emulsifiers.

[0034] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including:

[0035] Under the conditions of an alkaline solution mass ratio of 10%-30%, an additive volume fraction of 15%-25%, a temperature of 45℃-95℃, and a treatment time of 300s-1500s, an isolation groove is formed between adjacent first and second doped regions, such that the first included angle is greater than the second included angle; wherein, the additive includes any one of surfactants, dispersants, and emulsifiers.

[0036] According to another aspect of the present invention, a battery assembly is provided, including the battery structure described in any embodiment of the present invention.

[0037] According to another aspect of the present invention, a photovoltaic system is provided, including the battery module described in any embodiment of the present invention.

[0038] The battery structure provided by the technical solution of this invention includes: a substrate, and a plurality of first doped regions and a plurality of second doped regions disposed on a first side of the substrate; the first doped regions and the second doped regions are arranged alternately; an isolation groove is disposed on the substrate between adjacent first doped regions and second doped regions, the isolation groove including a first part and a second part, the sidewall of the first part being a first sidewall, and the sidewall of the second part being a second sidewall; the first angle between the first sidewall and the horizontal line is less than or greater than the second angle between the second sidewall and the horizontal line; since the sidewall of the isolation groove has an angular structure, the battery structure can form a stable support, with stronger stress resistance, and improved reliability of the battery structure.

[0039] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of a battery structure provided according to an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of another battery structure provided according to an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of another battery structure provided according to an embodiment of the present invention.

[0044] Figure 4This is a schematic diagram of another battery structure provided according to an embodiment of the present invention.

[0045] Figure 5 A schematic diagram of an isolation groove provided according to an embodiment of the present invention.

[0046] Figure 6 This is a flowchart of a method for preparing a battery structure according to an embodiment of the present invention. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] This invention provides a battery structure. Figure 1 This is a schematic diagram of a battery structure provided according to an embodiment of the present invention. Figure 2 This is a schematic diagram of another battery structure provided according to an embodiment of the present invention. Figure 3 This is a schematic diagram of another battery structure provided according to an embodiment of the present invention. Figure 4 This is a schematic diagram of another battery structure provided according to an embodiment of the present invention, with reference to... Figures 1-4 The battery structure includes:

[0050] A substrate 10, and a plurality of first doped regions 20 and a plurality of second doped regions 30 disposed on a first side of the substrate 10; the first doped regions 20 and the second doped regions 30 are arranged alternately; an isolation trench 40 is disposed between adjacent first doped regions 20 and second doped regions 30, the isolation trench 40 includes a first part 41 and a second part 42, the sidewall of the first part 41 is a first sidewall 01, and the sidewall of the second part 42 is a second sidewall 02; the first angle A between the first sidewall 01 and the horizontal line is less than or greater than the second angle B between the second sidewall 02 and the horizontal line; wherein, the extension direction X of the horizontal line is perpendicular to the depth direction Y of the isolation trench.

[0051] The battery structure can be a solar cell, which can be a back-contact solar cell. The substrate 10 is the foundation of the battery structure; the substrate 10 includes two opposing surfaces, namely a light-facing surface and a back-facing surface. The light-facing surface directly faces sunlight and has no electrodes to block it, thus maximizing the light absorption area and reducing shading loss, significantly improving the photoelectric conversion efficiency of the battery. The back-facing surface is the other side; the first side of the substrate 10 is the back-facing surface. The material of the substrate 10 can be monocrystalline silicon, polycrystalline silicon, or silicon wafers similar to monocrystalline silicon. The first doped region 20 can be an n-type doped region, and the second doped region 30 can be a p-type doped region. The substrate 10 can be an n-type substrate or a p-type substrate. The substrate 10 and the first doped region 20 or the second doped region 30 form a pn junction, generating a photovoltaic effect. When light shines on the solar cell, photons can excite electrons to jump from the valence band to the conduction band, forming electron-hole pairs. These charge carriers separate at the pn junction due to the electric field, generating current.

[0052] An isolation trench 40 is provided on the substrate between adjacent first doped regions 20 and second doped regions 30. The isolation trench 40 is used to isolate the first doped region 20 and the second doped region 30. The isolation trench 40 has a first part 41 and a second part 42. The first part 41 and the second part 42 have different structures and shapes. The first angle A between the first sidewall 01 and the horizontal line is smaller than or larger than the second angle B between the second sidewall 02 and the horizontal line. The first angle A between the first sidewall 01 and the horizontal line is smaller than the second angle B between the second sidewall 02 and the horizontal line, which can make the light absorption effect of the battery structure better and the short-circuit current higher. The first angle A between the first sidewall 01 and the horizontal line is larger than the second angle B between the second sidewall 02 and the horizontal line, which can make the subsequent passivation effect of the battery structure better and the open-circuit voltage higher. The angular structure of the sidewall of the isolation trench 40 provides stable support for the battery structure, strengthens stress resistance, and improves the reliability of the battery structure.

[0053] The battery structure provided by the technical solution of this invention includes: a substrate 10, and a plurality of first doped regions 20 and a plurality of second doped regions 30 disposed on a first side of the substrate 10; the first doped regions 20 and the second doped regions 30 are arranged alternately; an isolation groove 40 is disposed on the substrate between adjacent first doped regions 20 and second doped regions 30, the isolation groove 40 includes a first part 41 and a second part 42, the sidewall of the first part 41 is a first sidewall 01, and the sidewall of the second part 42 is a second sidewall 02; the first angle A between the first sidewall 01 and the horizontal line is less than or greater than the second angle B between the second sidewall 02 and the horizontal line; since the sidewall of the isolation groove 40 has an angular structure, the battery structure can form a stable support, with stronger stress resistance, and improved reliability of the battery structure.

[0054] Based on the above embodiments, optionally, refer to Figures 1-4 The first included angle A is greater than 0 degrees and less than 180 degrees; and / or the second included angle B is greater than 0 degrees and less than 180 degrees.

[0055] Specifically, the first included angle A is set to a range greater than 0 degrees and less than 180 degrees; or, the second included angle B is set to a range greater than 0 degrees and less than 180 degrees; or, the first included angle A is set to a range greater than 0 degrees and less than 180 degrees, and the second included angle B is set to a range greater than 0 degrees and less than 180 degrees. By making the first included angle A and the second included angle B different, different isolation groove 40 structures can be formed. While ensuring the reliability of the battery structure, different isolation groove 40 structures can achieve better light absorption and higher short-circuit current; or improve subsequent passivation effects and achieve higher open-circuit voltage.

[0056] Based on the above embodiments, optionally, refer to Figures 1-4 The first sidewall 01 is an inclined sidewall, and / or the second sidewall 02 is an inclined sidewall.

[0057] Among them, reference Figure 1 and Figure 4 The first sidewall 01 is an inclined sidewall, and the second sidewall 02 is an inclined sidewall. (Reference) Figure 2 The first sidewall 01 is an inclined sidewall, and the second sidewall 02 is a vertical sidewall. (Reference) Figure 3 The first sidewall 01 is a vertical sidewall, and the second sidewall 02 is an inclined sidewall. The first sidewall 01 and the second sidewall 02 of the isolation groove 40 have different inclination angles. At least one of the first sidewall 01 and the second sidewall 02 is an inclined sidewall. The inclined sidewall gives the sidewall of the isolation groove an angular structure, which makes the battery structure form a stable support, stronger stress resistance, and can improve the reliability of the battery structure.

[0058] Based on the above embodiments, optionally, refer to Figure 1The first included angle A is greater than 0 degrees and less than or equal to 90 degrees; and / or the second included angle B is greater than or equal to 90 degrees and less than 180 degrees.

[0059] Wherein, the range of the first included angle A is greater than 0 degrees and less than or equal to 90 degrees; or, the range of the second included angle B is greater than or equal to 90 degrees and less than 180 degrees; or, the range of the first included angle A is greater than 0 degrees and less than or equal to 90 degrees; and the range of the second included angle B is greater than or equal to 90 degrees and less than 180 degrees; this can make the contact area between the substrate 10 and the first doped region 20 and the second doped region 30 larger, which can enhance the built-in electric field generated when the substrate 10 contacts the first doped region 20 and the second doped region 30, which helps to improve the carrier transport efficiency, can make the light absorption efficiency better, the short-circuit current higher, and the photoelectric conversion efficiency higher.

[0060] Based on the above embodiments, optionally, refer to Figure 2 The first included angle A is greater than or equal to 90 degrees and less than 180 degrees; and / or the second included angle B is greater than 0 degrees and less than or equal to 90 degrees.

[0061] Wherein, the range of the first included angle A is greater than or equal to 90 degrees and less than 180 degrees; or, the range of the second included angle B is greater than 0 degrees and less than or equal to 90 degrees; or, the range of the first included angle A is greater than or equal to 90 degrees and less than 180 degrees; and the range of the second included angle B is greater than 0 degrees and less than or equal to 90 degrees; this allows for a larger lateral dimension of the isolation trench, which can improve the isolation effect of the isolation trench on the first doped region 20 and the second doped region 30, and can form a stable support, stronger stress resistance, and improve the reliability of the battery structure.

[0062] Based on the above embodiments, optionally, refer to Figure 4 The first included angle A is greater than or equal to 90 degrees and less than 180 degrees; and / or the second included angle B is greater than or equal to 90 degrees and less than 180 degrees.

[0063] Wherein, the range of the first included angle A is greater than or equal to 90 degrees and less than 180 degrees; or, the range of the second included angle B is greater than or equal to 90 degrees and less than 180 degrees; or, the range of the first included angle A is greater than or equal to 90 degrees and less than 180 degrees; the range of the second included angle B is greater than or equal to 90 degrees and less than 180 degrees; this can result in better passivation effect during subsequent battery structure passivation and higher open circuit ratio.

[0064] Based on the above embodiments, optionally, Figure 5 A schematic diagram of an isolation groove provided according to an embodiment of the present invention is shown below. Figure 1 andFigure 5 The first sidewall 01 includes a first subwall 011 and a second subwall 012, both of which include a first end and a second end; the second sidewall 02 includes a third subwall 021 and a fourth subwall 022, both of which include a third end and a fourth end; the second end of the first subwall 011 contacts the third end of the third subwall 021 to form a first common endpoint, and the second end of the second subwall 012 contacts the third end of the fourth subwall 022 to form a second common endpoint.

[0065] The line connecting the first end of the first sub-wall 011 and the first end of the second sub-wall 012 is the first connecting line C1; the line connecting the first common endpoint and the second common endpoint is the second connecting line C2, which divides the isolation groove 40 into the first part 41 and the second part 42; the line connecting the fourth end of the third sub-wall 021 and the fourth end of the fourth sub-wall 022 is the third connecting line C3.

[0066] The length of the second connection C2 is greater than the length of the first connection C1 or the length of the third connection C3; or, the length of the first connection C1 is greater than the length of the second connection C2 or the length of the third connection C3; or, the length of the third connection C3 is greater than the length of the second connection C2 or the length of the first connection C1.

[0067] The different lengths of the first connecting line C1, the second connecting line C2, and the third connecting line C3 can result in different tilt angles of the first sidewall 01 and the second sidewall 02, thus forming different structures of the isolation groove 40. While ensuring the reliability of the battery structure, different structures of the isolation groove 40 can achieve better light absorption and higher short-circuit current; or improve the subsequent passivation effect and achieve higher open-circuit voltage.

[0068] Based on the above embodiments, optionally, the length range of the first connection line is 20 micrometers to 250 micrometers; the length range of the second connection line is 20 micrometers to 250 micrometers; and the length range of the third connection line is 20 micrometers to 250 micrometers.

[0069] The lengths of the first connecting line range from 20 micrometers to 250 micrometers; the lengths of the second connecting line range from 20 micrometers to 250 micrometers; and the lengths of the third connecting line range from 20 micrometers to 250 micrometers. This ensures the isolation effect of the isolation groove 40 while improving the reliability of the battery structure by setting the above numerical ranges.

[0070] Optional, see reference Figure 1 and Figure 5 The length of the first sub-wall 011 is the same as or different from the length of the second sub-wall 012, and / or the length of the third sub-wall 021 is the same as or different from the length of the fourth sub-wall 022.

[0071] The isolation groove 40 includes a first part 41 and a second part 42; the first part 41 includes a first sidewall 01, which includes a first sub-wall 011 and a second sub-wall 012; the second part 42 includes a second sidewall 02, which includes a third sub-wall 021 and a fourth sub-wall 022; the first sub-wall 011 and the third sub-wall 021 are connected to form one sidewall of the isolation groove 40, and the second sub-wall 012 and the fourth sub-wall 022 are connected to form the other sidewall of the isolation groove 40. The length of the first sub-wall 011 may be the same as or different from the length of the second sub-wall 012; or, the length of the third sub-wall 021 may be the same as or different from the length of the fourth sub-wall 022; or, the length of the first sub-wall 011 may be the same as or different from the length of the second sub-wall 012, and the length of the third sub-wall 021 may be the same as or different from the length of the fourth sub-wall 022; the sidewalls on both sides of the isolation groove 40 may have the same or different lengths, the shape of the first part 41 of the isolation groove 40 may be a symmetrical structure or an asymmetrical structure, and the shape of the second part 42 of the isolation groove 40 may be a symmetrical structure or an asymmetrical structure, so that the shape of the isolation groove 40 can have multiple forms to meet the requirements of different light conversion efficiency, reliability and passivation effect.

[0072] Based on the above embodiments, optionally, refer to Figure 1 and Figure 5 The length of the first sub-wall 011 ranges from 10 nanometers to 500 nanometers, the length of the second sub-wall 012 ranges from 10 nanometers to 500 nanometers, the length of the third sub-wall 021 ranges from 0.5 micrometers to 10 micrometers, and the length of the fourth sub-wall 022 ranges from 0.5 micrometers to 10 micrometers.

[0073] Specifically, the length of the third sub-wall 021 is greater than or equal to the length of the first sub-wall 011, and the length of the fourth sub-wall 022 is greater than or equal to the length of the second sub-wall 012. Setting these lengths allows for better isolation of the isolation groove 40.

[0074] Based on the above embodiments, optionally, refer to Figures 1-4 The length of the first sidewall 01 may be the same as or different from the length of the second sidewall 02.

[0075] The length of the first sidewall 01 may be the same as or different from the length of the second sidewall 02, so that the shape of the isolation groove 40 can have various forms to meet the requirements of different conversion efficiency, reliability and passivation effect.

[0076] Based on the above embodiments, optionally, the length of the first sidewall 01 ranges from 10 nanometers to 500 nanometers; the length of the second sidewall 02 ranges from 0.5 micrometers to 10 micrometers.

[0077] The length of the first sidewall 01 is the same as the length of the second sidewall 02, or the length of the first sidewall 01 is less than the length of the second sidewall 02. Setting the above length can make the isolation groove 40 have a better isolation effect, better stress resistance, and higher reliability.

[0078] Based on the above embodiments, optionally, refer to Figures 1-4 The first doped region 20 and the plurality of second doped regions 30 each include an extension 50, which extends toward the isolation trench 40; the extension 50 is located above the isolation trench 40.

[0079] During the etching of the substrate 10, the substrate 10 is etched rapidly, while the etching rate of the portion of the substrate 10 near the first doped region 20 and the second doped region 30 decreases, causing the first doped region 20 and the second doped region 30 to form an extension 50. The extension 50 is located above the isolation trench 40, that is, the vertical projection of the extension 50 on the substrate 10 is located within the isolation trench 40.

[0080] Based on the above embodiments, optionally, refer to Figures 1-4 The length of the extension 50 along the first direction X ranges from 0.1 micrometers to 1 micrometer, and the thickness of the extension 50 along the second direction Y ranges from 10 nanometers to 500 nanometers.

[0081] The length of the extension 50 along the first direction X ranges from 0.1 micrometers to 1 micrometer, and the thickness of the extension 50 along the second direction Y ranges from 10 nanometers to 500 nanometers. This avoids the battery structure from being too long or too thin, which would result in poor stress resistance. Setting the above values ​​can improve the reliability of the battery structure.

[0082] Based on the above embodiments, this invention provides a method for preparing a battery structure. Figure 6 This is a flowchart of a method for preparing a battery structure according to an embodiment of the present invention, see reference. Figure 6 The preparation methods include:

[0083] S110 provides a substrate.

[0084] This involves providing a substrate and polishing the substrate.

[0085] S120, a plurality of first doped regions and a plurality of second doped regions are formed on the first side of the substrate.

[0086] S130, An isolation trench is formed on the substrate between adjacent first and second doped regions.

[0087] The isolation trench includes a first part and a second part. The sidewall of the first part is a first sidewall, and the sidewall of the second part is a second sidewall. The first angle between the first sidewall and the horizontal line is less than or greater than the second angle between the second sidewall and the horizontal line. The horizontal line extends in a direction perpendicular to the depth direction of the isolation trench.

[0088] The battery structure preparation method provided in this embodiment of the invention can make the sidewall of the isolation groove have an angled structure, which can make the battery structure form a stable support, stronger stress resistance, and improve the reliability of the battery structure.

[0089] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including:

[0090] An isolation trench is formed between adjacent first and second doped regions using an alkaline etching process.

[0091] Different shapes of isolation tanks can be formed by controlling the solution composition, temperature, and processing time of the alkaline etching process, so as to achieve a higher reliability of the isolation tanks.

[0092] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including: forming an isolation trench between adjacent first doped regions and second doped regions under the conditions of an alkaline solution mass ratio of 0.5%-10%, an additive volume fraction ratio of 0.1%-5%, a temperature of 40℃-95℃, and a processing time of 300s-1500s, such that the first included angle is smaller than the second included angle; wherein, the additive includes any one of surfactants, dispersants, and emulsifiers.

[0093] The solution composition includes alkaline solutions such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH4OH), or tetramethylammonium hydroxide (TMAH). Under the conditions of an alkaline solution mass ratio of 0.5%-10%, an additive volume fraction ratio of 0.1%-5%, a temperature of 40℃-90℃, and a processing time of 300s-1500s, an isolation groove is formed between adjacent first and second doped regions, such that the first included angle is smaller than the second included angle, the first included angle being greater than 0 degrees and less than 180 degrees; and / or, the second included angle being greater than 0 degrees and less than 180 degrees.

[0094] Under conditions of an alkaline solution mass ratio of 1%-5%, an additive volume fraction of 0.5%-2%, a temperature of 65℃-95℃, and a treatment time of 400s-900s, an isolation tank is formed between adjacent first and second doped regions, such that the first included angle is smaller than the second included angle, with the first included angle ranging from greater than 0 degrees to less than or equal to 90 degrees; and / or, the second included angle ranging from greater than or equal to 90 degrees to less than 180 degrees. Afterwards, deionized water cleaning, a mixture of alkaline and hydrogen peroxide cleaning, ozone cleaning, and HF cleaning are performed to remove chemical solution residues. After drying, the process proceeds to the next production step.

[0095] Based on the above embodiments, optionally, an isolation trench is formed between adjacent first doped regions and second doped regions, including: forming an isolation trench between adjacent first doped regions and second doped regions under the conditions of an alkaline solution mass ratio of 10%-30%, an additive volume fraction ratio of 15%-25%, a temperature of 45℃-95℃, and a processing time of 300s-1500s, such that the first included angle is greater than the second included angle; wherein, the additive includes any one of surfactants, dispersants, and emulsifiers.

[0096] The solution composition includes alkaline solutions such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH4OH), or tetramethylammonium hydroxide (TMAH). Under the conditions of an alkaline solution mass ratio of 10%-30%, an additive volume fraction ratio of 15%-25%, a temperature of 45℃-90℃, and a processing time of 300s-1500s, an isolation groove is formed between adjacent first and second doped regions, such that the first included angle is greater than the second included angle, the first included angle being greater than 0 degrees and less than 180 degrees; and / or, the second included angle being greater than 0 degrees and less than 180 degrees.

[0097] The solution composition includes alkaline solutions such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH4OH), or tetramethylammonium hydroxide (TMAH). Under conditions of an alkaline solution mass ratio of 15%-25%, an additive volume fraction of 18%-20%, a temperature of 70℃-95℃, and a processing time of 500s-800s, an isolation tank is formed between adjacent first and second doped regions, such that the first included angle is greater than the second included angle, with the first included angle being greater than or equal to 90 degrees and less than 180 degrees; and / or, the second included angle being greater than or equal to 90 degrees and less than 180 degrees. Afterwards, deionized water washing, a mixture of alkaline and hydrogen peroxide washing, ozone washing, and HF washing are performed to remove chemical solution residues. After drying, the process proceeds to the next production step.

[0098] This invention also provides a battery assembly, including the battery structure described in the above embodiments.

[0099] A battery module may include multiple battery structures, each of which is a solar cell. Multiple solar cells in a battery module can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current output. For example, the connection between individual battery cells can be achieved by welding ribbons, or the connection between individual battery strings can be achieved by busbars.

[0100] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance; for example, EVA film or POE film can be used, and the choice is based on the specific circumstances and is not limited here. The photovoltaic glass can cover the encapsulating film on the light-facing side of the solar cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach over 92%, which can protect the solar cell while minimizing the impact on its efficiency. Simultaneously, the encapsulating film can bond the photovoltaic glass and the solar cell together, and its presence provides sealing, insulation, waterproofing, and moisture protection for the solar cell.

[0101] The backsheet can be attached to the encapsulating film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0102] The battery assembly of this invention belongs to the same concept as the battery structure described in the above embodiments of this application and has corresponding beneficial effects. For technical details not covered in this embodiment, please refer to the battery structure described in any embodiment of this application.

[0103] This invention also provides a photovoltaic system, including the battery module described in the above embodiments.

[0104] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0105] The beneficial effects of the photovoltaic system in this embodiment of the invention are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0106] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0107] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A battery structure, characterized in that, include: A substrate, and a plurality of first doped regions and a plurality of second doped regions disposed on a first side of the substrate; the first doped regions and the second doped regions are arranged alternately; An isolation trench is provided on the substrate between adjacent first doped regions and second doped regions. The isolation trench includes a first part and a second part, the sidewall of the first part is a first sidewall, and the sidewall of the second part is a second sidewall. The first angle between the first sidewall and the horizontal line is smaller than the second angle between the second sidewall and the horizontal line; wherein the extension direction of the horizontal line is perpendicular to the depth direction of the isolation groove; The first angle between the first sidewall and the horizontal line is the angle between the horizontal line drawn through the end where the first sidewall connects to the second sidewall and the first sidewall; the second angle between the second sidewall and the horizontal line is the angle between the horizontal line drawn through the end where the second sidewall connects to the bottom of the isolation groove and the second sidewall. The first sidewall includes a first subwall and a second subwall, both of which include a first end and a second end; the second sidewall includes a third subwall and a fourth subwall, both of which include a third end and a fourth end; the second end of the first subwall and the third end of the third subwall are in contact as a first common endpoint, and the second end of the second subwall and the third end of the fourth subwall are in contact as a second common endpoint. The line connecting the first end of the first sub-wall and the first end of the second sub-wall is the first connecting line; the line connecting the first common endpoint and the second common endpoint is the second connecting line, which divides the isolation groove into the first part and the second part. The length of the second connection is greater than the length of the first connection.

2. The battery structure according to claim 1, characterized in that: The first included angle is greater than 0 degrees and less than 180 degrees; and / or, the second included angle is greater than 0 degrees and less than 180 degrees.

3. The battery structure according to claim 1, characterized in that: The first sidewall is an inclined sidewall, and / or the second sidewall is an inclined sidewall.

4. The battery structure according to claim 3, characterized in that: The first included angle is greater than 0 degrees and less than or equal to 90 degrees; and / or, the second included angle is greater than or equal to 90 degrees and less than 180 degrees.

5. The battery structure according to claim 3, characterized in that: The second included angle is greater than 0 degrees and less than or equal to 90 degrees.

6. The battery structure according to claim 3, characterized in that: The line connecting the fourth end of the third sub-wall to the fourth end of the fourth sub-wall is the third connecting line; The length of the second connecting line is greater than the length of the third connecting line; or, the length of the first connecting line is greater than the length of the third connecting line; or, the length of the third connecting line is greater than the length of the second connecting line or the length of the first connecting line.

7. The battery structure according to claim 6, characterized in that: The length of the first connection ranges from 20 micrometers to 250 micrometers; the length of the second connection ranges from 20 micrometers to 250 micrometers; and the length of the third connection ranges from 20 micrometers to 250 micrometers.

8. The battery structure according to claim 6, characterized in that: The length of the first sub-wall is the same as or different from the length of the second sub-wall, and / or the length of the third sub-wall is the same as or different from the length of the fourth sub-wall.

9. The battery structure according to claim 8, characterized in that: The length of the first sub-wall ranges from 10 nanometers to 500 nanometers, and the length of the second sub-wall ranges from 10 nanometers to 500 nanometers. The length of the third sub-wall ranges from 0.5 micrometers to 10 micrometers, and the length of the fourth sub-wall ranges from 0.5 micrometers to 10 micrometers.

10. The battery structure according to claim 1, characterized in that: The length of the first sidewall may be the same as or different from the length of the second sidewall.

11. The battery structure according to claim 1, characterized in that: The length of the first sidewall ranges from 10 nanometers to 500 nanometers; the length of the second sidewall ranges from 0.5 micrometers to 10 micrometers.

12. The battery structure according to claim 1, characterized in that: The first doped region and the plurality of second doped regions each include an extension portion, and the extension portion extends toward the isolation trench; The extension is located above the isolation groove.

13. The battery structure according to claim 12, characterized in that: The length of the extension in the first direction ranges from 0.1 micrometers to 1 micrometer, and the thickness of the extension in the second direction ranges from 10 nanometers to 500 nanometers.

14. A method for preparing a battery structure, characterized in that, include: Provide a base; Multiple first doped regions and multiple second doped regions are formed on the first side of the substrate; An isolation trench is formed on the substrate between adjacent first doped regions and second doped regions; the isolation trench includes a first portion and a second portion, the sidewall of the first portion is a first sidewall, and the sidewall of the second portion is a second sidewall; the first angle between the first sidewall and the horizontal line is smaller than the second angle between the second sidewall and the horizontal line; wherein the extension direction of the horizontal line is perpendicular to the depth direction of the isolation trench; The first angle between the first sidewall and the horizontal line is the angle between the horizontal line drawn through the end where the first sidewall connects to the second sidewall and the first sidewall; the second angle between the second sidewall and the horizontal line is the angle between the horizontal line drawn through the end where the second sidewall connects to the bottom of the isolation groove and the second sidewall. The first sidewall includes a first subwall and a second subwall, both of which include a first end and a second end; the second sidewall includes a third subwall and a fourth subwall, both of which include a third end and a fourth end; the second end of the first subwall and the third end of the third subwall are in contact as a first common endpoint, and the second end of the second subwall and the third end of the fourth subwall are in contact as a second common endpoint. The line connecting the first end of the first sub-wall and the first end of the second sub-wall is the first connecting line; the line connecting the first common endpoint and the second common endpoint is the second connecting line, which divides the isolation groove into the first part and the second part. The length of the second connection is greater than the length of the first connection.

15. The preparation method according to claim 14, characterized in that, An isolation trench is formed between adjacent first and second doped regions, including: An isolation trench is formed between adjacent first and second doped regions using an alkaline etching process.

16. The preparation method according to claim 15, characterized in that, An isolation trench is formed between adjacent first and second doped regions, including: An isolation groove is formed between adjacent first and second doped regions under the conditions of an alkaline solution mass ratio of 0.5%-10%, an additive volume fraction ratio of 0.1%-5%, a temperature of 40℃-95℃, and a treatment time of 300s-1500s, such that the first included angle is smaller than the second included angle; wherein, the additive includes any one of surfactants, dispersants, and emulsifiers.

17. A battery assembly, characterized in that, Includes the battery structure described in any one of claims 1-13.

18. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 17.

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