阅读说明：本技术 一种单晶硅片的制备方法、电池片及电池组件 (Preparation method of monocrystalline silicon wafer, battery piece and battery assembly ) 是由 王彪 仲春华 王建波 朱琛 吕俊 杨飞 于 2020-05-09 设计创作，主要内容包括：本发明提供的一种单晶硅片的制备方法、电池片及电池组件,包括：利用具有预设晶向的籽晶,制备得到具有预设晶向的单晶硅棒；沿平行于单晶硅棒的轴线方向对单晶硅棒进行开方操作；根据预设晶向和目标晶向,确定单晶硅棒的切割方向,并沿切割方向切割单晶硅棒,得到具有目标晶向的单晶硅片。本发明中,利用具有预设晶向的单晶硅棒,并沿根据预设晶向和目标晶向确定的切割方向切割所述单晶硅棒,因此在切割单晶硅棒时,切片机的金刚线会沿切割方向对所述单晶硅棒进行斜切,从而在不用增加单晶硅棒尺寸的情况下,得到具有较大尺寸和目标晶向的单晶硅片,提升了大尺寸单晶硅片的质量,降低了大尺寸单晶硅片的生产成本和制备难度。(The invention provides a preparation method of a monocrystalline silicon wafer, a battery piece and a battery assembly, which comprise the following steps: preparing a monocrystalline silicon rod with a preset crystal orientation by using seed crystals with the preset crystal orientation; performing a squaring operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod; and determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain the single crystal silicon wafer with the target crystal orientation. According to the method, the silicon single crystal rod with the preset crystal orientation is cut along the cutting direction determined according to the preset crystal orientation and the target crystal orientation, so that when the silicon single crystal rod is cut, a diamond wire of a slicing machine can obliquely cut the silicon single crystal rod along the cutting direction, a silicon single crystal wafer with a larger size and a target crystal orientation is obtained under the condition that the size of the silicon single crystal rod is not increased, the quality of the large-size silicon single crystal wafer is improved, and the production cost and the preparation difficulty of the large-size silicon single crystal wafer are reduced.)

1. A method for producing a single crystal silicon wafer, comprising:

preparing a monocrystalline silicon rod with a preset crystal orientation by using a seed crystal with the preset crystal orientation;

performing an extracting operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod;

and determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain the single crystal silicon wafer with the target crystal orientation.

2. The method according to claim 1, wherein the step of determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation specifically comprises:

determining a target included angle between the preset crystal orientation and the target crystal orientation according to the preset crystal orientation and the target crystal orientation;

and determining the cutting direction of the single crystal silicon rod according to the axis direction of the single crystal silicon rod and the target included angle.

3. The method of claim 1, wherein the predetermined crystal orientation is (110), the target crystal orientation is (100), and an included angle between the cutting direction and an axial direction of the single crystal silicon rod is 30 to 60 degrees.

4. The method of claim 3 wherein the cutting direction is at a 45 degree angle to the direction of the axis of the single crystal silicon rod.

5. The method of claim 1, wherein after the step of obtaining a single crystal silicon wafer having the target crystal orientation, the method further comprises:

and preparing a battery piece by using the monocrystalline silicon piece.

6. The method of claim 5, wherein the cell sheet has a front electrode and front fine grid lines disposed in one side of the cell sheet and a back electrode and an aluminum back field disposed in the other side of the cell sheet.

7. The method according to claim 6, wherein after the step of preparing a cell using the single-crystal silicon wafer, the method further comprises:

and preparing the battery pack by using the battery piece.

8. The method according to claim 7, wherein the step of preparing the battery assembly by using the battery piece specifically comprises:

connecting a first preset number of the battery pieces by using a conducting wire to obtain a battery string;

and electrically connecting the battery strings of a second preset number by using the bus bars to obtain the battery assembly.

9. A cell comprising the single-crystal silicon wafer produced by the method for producing a single-crystal silicon wafer according to any one of claims 1 to 4.

10. A battery pack comprising the battery sheet of claim 9.

Technical Field

The invention relates to the technical field of monocrystalline silicon, in particular to a preparation method of a monocrystalline silicon piece, a battery piece and a battery assembly.

Background

With the continuous consumption of traditional energy and the negative impact on the environment, the development and utilization of solar energy as a pollution-free and renewable energy are rapidly developed.

The method for preparing the large-size monocrystalline silicon wafer is characterized in that a monocrystalline silicon rod with a large size and a specific crystal orientation is prepared by using a seed crystal with a specific crystal orientation in a monocrystalline furnace through steps of feeding, melting, seeding, shouldering, shoulder rotating, isodiametric growth, ending and the like, and the monocrystalline silicon rod with the large size is further subjected to operations of squaring, slicing and the like to prepare the large-size monocrystalline silicon wafer.

However, in the current scheme, the preparation of the large-size monocrystalline silicon wafer requires the drawing of the large-size monocrystalline silicon rod, and the drawing process of the large-size monocrystalline silicon rod has high difficulty and high drawing cost, so that the cost for preparing the monocrystalline silicon rod is increased; meanwhile, the uniformity of the inside of the single crystal silicon rod is difficult to ensure in the process of drawing a large-sized single crystal silicon rod, and thus, the quality of the single crystal silicon wafer prepared by using the single crystal silicon rod is poor.

Disclosure of Invention

The invention provides a preparation method of a monocrystalline silicon piece, a battery piece and a battery assembly, and aims to improve the quality of a large-size monocrystalline silicon piece and reduce the production cost and the preparation difficulty of the large-size monocrystalline silicon piece.

In a first aspect, an embodiment of the present invention provides a method for preparing a monocrystalline silicon wafer, where the method includes:

preparing a monocrystalline silicon rod with a preset crystal orientation by using a seed crystal with the preset crystal orientation;

performing an extracting operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod;

and determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain the single crystal silicon wafer with the target crystal orientation. .

Optionally, the step of determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation specifically includes:

determining a target included angle between the preset crystal orientation and the target crystal orientation according to the preset crystal orientation and the target crystal orientation;

and determining the cutting direction of the single crystal silicon rod according to the axis direction of the single crystal silicon rod and the target included angle, wherein the included angle between the axis direction of the single crystal silicon rod and the cutting direction of the single crystal silicon rod is the target included angle.

Optionally, the preset crystal orientation is (110), the target crystal orientation is (100), and an included angle between the cutting direction and the axis direction of the single crystal silicon rod is 30 to 60 degrees.

Optionally, an included angle between the cutting direction and the axis direction of the single crystal silicon rod is 45 degrees.

Optionally, after the step of obtaining the monocrystalline silicon wafer with the target crystal orientation, the method further includes:

and preparing a battery piece by using the monocrystalline silicon piece.

Optionally, a front electrode and a front fine grid line are arranged in one surface of the battery piece, and a back electrode and an aluminum back field are arranged in the other surface of the battery piece.

Optionally, after the step of preparing a cell using the monocrystalline silicon wafer, the method further includes:

and preparing the battery pack by using the battery piece.

Optionally, the step of preparing the battery assembly by using the battery piece specifically includes:

connecting a first preset number of the battery pieces by using a conducting wire to obtain a battery string;

and electrically connecting the battery strings of a second preset number by using the bus bars to obtain the battery assembly.

In a second aspect, the embodiment of the invention provides a battery piece, and the battery piece comprises a monocrystalline silicon piece prepared by the preparation method of the monocrystalline silicon piece.

The invention provides a battery pack including the battery sheet in a third aspect.

Based on the preparation method of the monocrystalline silicon wafer, the battery piece and the battery component, the application has the following beneficial effects:

according to the silicon single crystal slicing method and the silicon single crystal slicing device, the silicon single crystal rod with the preset crystal orientation is cut along the cutting direction determined according to the preset crystal orientation and the target crystal orientation, so that when the silicon single crystal rod is cut, a diamond wire of the slicing machine can be used for obliquely cutting the silicon single crystal rod along the cutting direction, a silicon single crystal slice with a larger size and a target crystal orientation is obtained under the condition that the size of the silicon single crystal rod is not increased, the quality of the large-size silicon single crystal slice is improved, and the production cost and the preparation difficulty of the large-size silicon single crystal slice are reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a flow chart showing the steps of a method for manufacturing a single crystal silicon wafer according to a first embodiment of the present invention;

FIG. 2 is a schematic drawing showing the drawing of a single crystal silicon rod according to a first embodiment of the present invention;

FIG. 3 is a schematic illustration of a slice of a single crystal silicon rod according to a first embodiment of the present disclosure;

FIG. 4 is a schematic diagram showing a crystal plane of a single crystal silicon in accordance with a first embodiment of the present invention;

FIG. 5 shows a side view of a slice of a single crystal silicon rod in accordance with a first embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a monocrystalline silicon wafer according to a first embodiment of the invention;

FIG. 7 is a flowchart showing the steps of a method for producing a single crystal silicon wafer according to a second embodiment of the present invention;

fig. 8 is a schematic structural diagram of a battery cell according to a second embodiment of the invention;

fig. 9 shows a structural schematic diagram of an 1/2 battery piece in the second embodiment of the invention;

fig. 10 is a schematic structural view showing a battery pack according to a second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

Referring to fig. 1, fig. 1 is a flow chart showing steps of a method for manufacturing a single crystal silicon wafer according to a first embodiment of the present invention. The method may comprise the steps of:

and 101, preparing a monocrystalline silicon rod with a preset crystal orientation by using a seed crystal with the preset crystal orientation.

In this step, a single crystal silicon rod having a predetermined crystal orientation may be prepared by the czochralski method using a seed crystal having the predetermined crystal orientation.

The seed crystals used for preparing the single crystal silicon rod are small crystals with the same crystal orientation as the single crystal silicon rod crystals, are seeds for growing the single crystal silicon rod, and are also called seed crystals, so that the seed crystals with different crystal orientations can be used as the seed crystals to obtain the single crystal silicon rods with different crystal orientations, when the single crystal silicon rod is prepared by adopting a Czochralski method, the seed crystals with a certain crystal orientation are needed to be used as the Czochralski single crystal seeding, and the crystal orientations mainly comprise three types (100), (110) and (111).

In the embodiment of the invention, a single crystal silicon rod is pulled by a straight pulling single crystal method, the pulling process of the single crystal silicon rod is completed through the steps of feeding, melting, seeding, shouldering, shoulder rotating, equal-diameter growing, ending and the like, concretely, in the middle of the melting and seeding steps, after silicon materials are completely melted, heating power is adjusted to control the temperature of a melt, after the melt is stabilized, a seed crystal is lowered to a distance of 3-5 mm from the liquid level of the melt, the seed crystal is preheated to reduce the temperature difference between the seed crystal and the molten silicon, so that the thermal stress generated in the seed crystal when the seed crystal is contacted with the molten silicon is reduced, further, after the seed crystal is preheated, the seed crystal is lowered to the surface of the melt to be fully contacted, the process is called fusion, although the seed crystal is prepared by a dislocation-free silicon single crystal, when the seed crystal is inserted into the melt, dislocation is generated under the action of the thermal stress and the surface tension caused by the temperature difference between the seed crystal and the molten silicon, therefore, by adopting the seeding process after welding, dislocation can disappear, a dislocation-free growth state is established, and finally the silicon single crystal rod is prepared.

It can be known from crystallography that, the atomic densities and spacings of the crystal planes of the silicon crystal are not consistent, which causes the difference of the acting forces among atoms, so that the growth speeds of the crystal planes are not consistent, the crystal direction of the single crystal silicon rod obtained by pulling the seed crystal with the preset crystal direction of (100) is also (100), and because four atom dense arrangement planes {111} are obliquely intersected with the cylindrical crystal, four continuous crystal lines parallel to the axis of the single crystal silicon rod are formed on the periphery of the pulled cylindrical single crystal silicon rod; the crystal orientation of the single crystal silicon rod obtained by pulling the seed crystal with the preset crystal orientation of (111) is also (111), and three continuous crystal lines parallel to the axis of the single crystal silicon rod are formed at the periphery of the cylindrical single crystal silicon rod obtained by pulling because three atom dense planes {111} are obliquely intersected with the cylindrical crystal; the crystal orientation of the single crystal silicon rod obtained by pulling the seed crystal with the preset crystal orientation of (110) is also (110), and two continuous crystal lines parallel to the axis of the single crystal silicon rod are formed at the periphery of the cylindrical single crystal silicon rod obtained by pulling due to the inclined intersection of the two atomic dense arrangement surfaces {111} and the cylindrical crystal. And a plurality of crystal wires are uniformly distributed on the periphery of the single crystal silicon rod, and if dislocation is generated in the process of drawing the single crystal silicon rod, the crystal wires are interrupted.

In the field of solar cells, a monocrystalline silicon wafer is prepared by a process of squaring and cutting a monocrystalline silicon rod, and then a cell is prepared by the steps of cleaning, texturing, diffusing, etching, Plasma Enhanced Chemical Vapor Deposition (PECVD) coating, screen printing of electrodes, sintering, testing, sorting and the like of the monocrystalline silicon wafer, and finally the cell is assembled into a cell assembly.

In the texturing process of the monocrystalline silicon wafer, a micro tetrahedral pyramid structure of a (111) surface is formed on the surface of the monocrystalline silicon wafer by erosion of chemical erosion liquid, so that the reflectivity of the surface of the monocrystalline silicon wafer is reduced, and the efficiency of a battery assembly is improved. In the process of texturing, the density of covalent bonds of a (100) plane is lower than that of a (111) plane, the connection among crystal planes of a crystal plane group is weaker, and the silicon wafer is easy to corrode, so that the corrosion rate of the (100) plane is higher than that of the (111) plane, and in the process of chemical etching liquid, a plurality of densely distributed four-sided pyramid bodies with the (111) plane on the surface are easy to generate on the surface of the monocrystalline silicon wafer with the (100) crystal direction, and a textured silicon surface is formed, so in the field of solar cells, the monocrystalline silicon wafer with the (100) crystal direction is mostly adopted to prepare a cell slice and a cell component.

102, performing an opening operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod.

In the step, the prepared monocrystalline silicon rod can be subjected to squaring operation along the direction parallel to the axis of the monocrystalline silicon rod to obtain a monocrystalline silicon square rod with a rectangular cross section, so that the monocrystalline silicon square rod can be subjected to cutting operation in the subsequent step to obtain a monocrystalline silicon wafer with a rectangular structure.

Fig. 2 is a schematic diagram illustrating the extraction of a single crystal silicon rod according to a first embodiment of the present invention, and referring to fig. 2, when an extraction machine is used to extract a single crystal silicon rod 10, an extraction direction 40 of a diamond wire 30 of the extraction machine is parallel to an axial direction of the single crystal silicon rod 10, that is, the extraction direction 40 of the diamond wire 30 of the extraction machine is parallel to an axial line 20 of the single crystal silicon rod, and a single diamond wire 30 may be used to perform four cutting operations on the single crystal silicon rod 10 to obtain a single crystal silicon square rod with a rectangular cross section, or four diamond wires 30 constituting a rectangular structure may be used to perform one cutting operation on the single crystal silicon rod 10 to obtain a single crystal silicon square rod with a rectangular cross section.

Step 103, determining a cutting direction of the single crystal silicon rod according to the preset crystal orientation and a target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain a single crystal silicon wafer with the target crystal orientation.

In this step, the cutting direction of the single crystal silicon rod may be determined according to a preset crystal orientation of the single crystal silicon rod and a target crystal orientation of the single crystal silicon wafer, so that the single crystal silicon wafer having the target crystal orientation is obtained after the single crystal silicon rod is cut along the cutting direction.

In the embodiment of the present application, since it is necessary to fabricate a cell assembly using the fabricated single crystal silicon wafer, the target crystal orientation is a (100) crystal orientation, the preset crystal orientation of the single crystal silicon rod is the crystal orientation of the seed crystal, and as can be seen from the above discussion, the crystal orientation of the seed crystal mainly comprises three crystal orientations (100), (110) and (111), in a traditional method for preparing monocrystalline silicon wafers, a seed crystal with a preset crystal orientation of (100) is usually adopted, a monocrystalline silicon rod with the crystal orientation of (100) is prepared through the steps of seeding, shouldering, shoulder rotating, equal-diameter growth, ending and the like, then the monocrystalline silicon rod with the crystal orientation of (100) is cut along the direction vertical to the axis of the monocrystalline silicon rod, and finally the monocrystalline silicon wafer with the crystal orientation of (100) is obtained, that is, if the predetermined crystal orientation is (100) and the target crystal orientation is (100), it can be determined that the cutting direction of the single crystal silicon rod is perpendicular to the axial direction of the single crystal silicon rod.

Specifically, referring to fig. 3, fig. 3 shows a schematic view of slicing a single crystal silicon rod according to a first embodiment of the present invention, as shown in fig. 3(a), a cutting direction 50 of a diamond wire 30 of a slicing machine forms an angle of 90 degrees with an axis 20 of the single crystal silicon rod 10, that is, the single crystal silicon rod 10 having a (100) crystal orientation is cut along a direction perpendicular to the axis of the single crystal silicon rod 10, so as to finally obtain a single crystal silicon wafer having a (100) crystal orientation.

If the seed crystal with the preset crystal orientation of (110) is adopted, the monocrystalline silicon rod with the crystal orientation of (110) is prepared through the steps of seeding, shouldering, shoulder rotating, isodiametric growth, ending and the like, and then the monocrystalline silicon rod with the crystal orientation of (110) is obliquely cut at a certain angle, and finally the monocrystalline silicon piece with the crystal orientation of (100) is obtained.

Referring to fig. 4, fig. 4 is a schematic diagram illustrating a crystal plane of a single crystal silicon according to a first embodiment of the present invention, wherein a crystal plane having a (100) crystal direction in the single crystal silicon is located in a plane of the hexahedral cell parallel to the yz plane, and a crystal plane having a (110) crystal direction in the single crystal silicon coincides with a facing angle of the hexahedral cell and is parallel to the z axis, so that an included angle between the crystal plane having the (100) crystal direction and the crystal plane having the (110) crystal direction is 45 degrees, that is, an included angle between the (100) crystal direction and the (110) crystal direction is 45 degrees, so that if the crystal direction of the prepared single crystal silicon rod is (110), the single crystal silicon wafer having the crystal direction (100) can be obtained by slicing the single crystal silicon rod along a cutting direction having an included angle of 45 degrees with the axis direction of the single crystal silicon rod.

Specifically, as shown in fig. 3(b), the cutting direction 50 of the diamond wire 30 of the slicing machine is at an angle of 45 degrees with respect to the axis 20 of the single crystal silicon rod 10, that is, the single crystal silicon rod 10 having the (110) crystal orientation is obliquely cut in a direction at an angle of 45 degrees with respect to the axis 20 of the single crystal silicon rod 10, and finally, a single crystal silicon wafer having the (100) crystal orientation is obtained.

Referring to fig. 5, fig. 5 shows a side view of a slice of a single crystal silicon rod in a first embodiment of the present invention, fig. 5(a) corresponds to the side view of the slicing process in fig. 3(a), and a cutting direction 50 of the slicing machine when cutting the single crystal silicon 10 is perpendicular to an axis 20 of the single crystal silicon rod 10, that is, the single crystal silicon rod 10 with a (100) preset crystal orientation is cut along a direction perpendicular to the axis of the single crystal silicon rod 10, so as to finally obtain a single crystal silicon wafer with a (100) target crystal orientation; fig. 5(b) corresponds to the side view of the slicing process in fig. 3(b), the slicing machine cuts the monocrystalline silicon 10 in a cutting direction 50 at an angle of 45 degrees with respect to the axis 20 of the monocrystalline silicon rod 10, that is, the monocrystalline silicon rod 10 having the (110) predetermined crystal orientation is obliquely cut in a direction at an angle of 45 degrees with respect to the axis 20 of the monocrystalline silicon rod 10, so as to finally obtain a monocrystalline silicon wafer having the (100) target crystal orientation.

Referring to FIG. 6, FIG. 6 shows a schematic structural diagram of a single crystal silicon wafer according to a first embodiment of the present invention, and FIG. 6(a) corresponds to the single crystal silicon wafer 70 obtained by slicing in FIGS. 3(a) and 5(a), and if the cross-section of the single crystal silicon rod is a square structure with a side length of a, the single crystal silicon wafer 70 obtained by slicing is in a square structure with a side length of a. FIG. 6(b) corresponds to the single-crystal silicon wafer 70 obtained by slicing in FIG. 3(b) and FIG. 5(b), and if the cross-section of the single-crystal silicon rod has a square configuration with a side length of a, the single-crystal silicon wafer 70 obtained by slicing has a rectangular configuration with a short side length of a.

Therefore, compared with the mode of slicing in the cutting direction perpendicular to the axis of the single crystal silicon rod, the mode of slicing in the cutting direction with a certain included angle with the axis of the single crystal silicon rod has the advantage that the area of the finally obtained single crystal silicon wafer is large, and the single crystal silicon wafer has the target crystal orientation (100) suitable for the field of solar cells.

In an embodiment of the present invention, a method for manufacturing a single crystal silicon wafer includes: preparing a monocrystalline silicon rod with a preset crystal orientation by using seed crystals with the preset crystal orientation; performing a squaring operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod; and determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain the single crystal silicon wafer with the target crystal orientation. According to the method, the silicon single crystal rod with the preset crystal orientation is used, and the silicon single crystal rod is cut along the cutting direction determined according to the preset crystal orientation and the target crystal orientation, so that when the silicon single crystal rod is cut, a diamond wire of a slicing machine can be used for obliquely cutting the silicon single crystal rod along the cutting direction, a silicon single crystal wafer with a larger size and a target crystal orientation is obtained under the condition that the size of the silicon single crystal rod is not increased, the quality of the large-size silicon single crystal wafer is improved, and the production cost and the preparation difficulty of the large-size silicon single crystal wafer are reduced.

Example two

Referring to fig. 7, a flow chart illustrating the steps of a method for manufacturing a single crystal silicon wafer according to a second embodiment of the present invention may include the steps of:

step 201, preparing a monocrystalline silicon rod with a preset crystal orientation by using a seed crystal with the preset crystal orientation.

This step may specifically refer to step 101, which is not described herein again.

202, performing an opening operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod.

This step may specifically refer to step 102, which is not described herein again.

Step 203, determining a target included angle between the preset crystal orientation and the target crystal orientation according to the preset crystal orientation and the target crystal orientation.

In this step, a target included angle between the preset crystal orientation and the target crystal orientation may be determined according to the preset crystal orientation and the target crystal orientation.

Specifically, as shown in fig. 4, if the predetermined crystal direction is (110), the target crystal direction is (100), a crystal plane of the single crystal silicon having the predetermined crystal direction (100) is located in a plane of the hexahedral cell parallel to the yz plane, and a crystal plane of the single crystal silicon having the target crystal direction (110) coincides with a facing angular line of the hexahedral cell and is parallel to the z axis, so that an included angle between the crystal plane having the predetermined crystal direction (100) and the crystal plane having the target crystal direction (110) is 45 degrees, that is, a target included angle between the predetermined crystal direction (100) and the target crystal direction (110) is 45 degrees.

And 204, determining the cutting direction of the single crystal silicon rod according to the axis direction of the single crystal silicon rod and the target included angle.

In this step, the cutting direction of the single crystal silicon rod may be determined according to the axis direction of the single crystal silicon rod and the target included angle.

Optionally, the preset crystal orientation may be (110), the target crystal orientation may be (100), and an included angle between the cutting direction and the axial direction of the single crystal silicon rod is 30 to 60 degrees.

Specifically, when the preset crystal orientation is (110) and the target crystal orientation is (100), the target included angle between the preset crystal orientation (100) and the target crystal orientation (110) is 45 degrees, the diamond wire of the slicing machine can be obliquely cut along the cutting direction forming a certain included angle with the axis direction of the single crystal silicon rod, so that a large-area single crystal silicon wafer can be obtained, and the obliquely cut single crystal silicon wafer has the target crystal orientation (100), so that the included angle between the cutting direction of the diamond wire of the slicing machine and the axis direction of the single crystal silicon rod has a small difference value with the target included angle, for example, the included angle between the cutting direction and the axis direction of the single crystal silicon rod can be set within a range of 45 ± 15 degrees, that is, the included angle between the cutting direction and the axis direction of the single crystal silicon rod is 30 degrees to 60 degrees.

Preferably, an included angle between the cutting direction and the axis direction of the single crystal silicon rod is equal to a target included angle between a preset crystal orientation and a target crystal orientation, that is, an included angle between the cutting direction and the axis direction of the single crystal silicon rod is selected to be 45 degrees.

Step 205, cutting the single crystal silicon rod along the cutting direction to obtain a single crystal silicon wafer with the target crystal orientation.

In this step, the single crystal silicon rod may be cut by a diamond wire of a slicer in the cutting direction using a slicer, thereby obtaining a single crystal silicon wafer having the target crystal orientation.

And step 206, preparing a battery piece by using the monocrystalline silicon piece.

In this step, a cell can be prepared using the prepared single crystal silicon wafer having the target crystal orientation.

Specifically, the cell is prepared by the steps of cleaning, texturing, diffusing, etching, PECVD (plasma enhanced chemical vapor deposition) coating, screen printing of an electrode, sintering, testing, sorting and the like of a monocrystalline silicon wafer.

In the embodiment of the invention, the battery pieces can be continuously assembled to form the battery assembly, and because the adjacent battery pieces need to be welded and connected in the assembly process of the battery pieces, the battery pieces can be set to be in a rectangular chamfer structure, so that the welding and connection between the battery pieces can be carried out at the chamfer parts of the battery pieces, and in addition, different electrode piece graphic designs can be provided in the production of the solar battery according to the requirements of assembly technology.

Optionally, a front electrode and a front fine grid line are arranged in one surface of the battery piece, and a back electrode and an aluminum back field are arranged in the other surface of the battery piece.

Referring to fig. 8, fig. 8 shows a schematic structural diagram of a cell in a second embodiment of the present invention, as shown in fig. 8(a), one surface of a cell 80 is in contact with sunlight and collects current generated by photoelectric conversion, a front electrode 81 and front fine grid lines 82 are arranged in the surface, wherein the front electrode 81 is used for collecting current generated by the main body of the cell 80, the front fine grid lines 82 are distributed on the surface of the cell 80 for collecting current and conducting the collected current to the front electrode 81, as shown in fig. 8(b), the other surface of the cell 80 is not in contact with the sunlight, a back electrode 83 and an aluminum back field 84 are arranged in the surface, wherein the back electrode 83 can be connected with the front electrode 81 of an adjacent cell through a conductive wire so as to electrically connect two adjacent cells, the aluminum back field 84 can be prepared by screen printing an aluminum paste, on one hand, a P + layer is prepared on the formed electron-hole pair (PN junction), so that the probability of minority carrier recombination on the back surface is reduced, and on the other hand, an alloy back field can be formed, and the long-wave partial light has a certain reflection effect, so that the photoelectric conversion efficiency of the cell is improved.

And step 207, preparing a battery pack by using the battery piece.

In this step, a battery module may be prepared using the prepared battery sheet.

Specifically, the battery pack is prepared by using the battery pieces through the steps of series welding, typesetting, laminating, framing, gluing, curing, testing and the like.

In the embodiment of the invention, the laser cutting technology can be combined to perform laser cutting on the battery piece, the battery piece is cut into 1/2 battery pieces and 1/4 battery pieces in a halving way and a quartering way, the battery pieces are assembled by utilizing 1/2 battery pieces and 1/4 battery pieces obtained after cutting, and the battery assembly is prepared through assembly technologies such as splicing and laminating.

Referring to fig. 9 and fig. 9, which are schematic structural diagrams illustrating 1/2 battery pieces in a second embodiment of the present invention, as shown in fig. 9 and fig. 8, 1/2 battery pieces 90 are obtained by halving battery pieces 80 by using a laser cutting technique.

Optionally, step 207 specifically includes:

and a substep 2071 of connecting the first preset number of battery pieces by using a conductive wire to obtain a battery string.

In this step, a first preset number of the battery pieces may be connected using a conductive wire, resulting in a battery string.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a battery assembly according to a second embodiment of the present invention, where the battery assembly includes a second predetermined number of battery strings 110, where the battery strings 110 include a first predetermined number 1/2 of battery pieces 90, and the first predetermined number 1/2 of battery pieces 90 are connected in series through a conductive wire 100.

And a substep 2072 of electrically connecting the second preset number of battery strings by using bus bars to obtain the battery assembly.

In this step, a second predetermined number of the battery strings may be electrically connected by using bus bars, so as to obtain the battery assembly.

Referring to fig. 10, the battery assembly includes a second preset number of battery strings 110, and the second preset number of battery strings 110 are electrically connected through bus bars, where the electrical connection may be a series connection or a parallel connection, and may be specifically determined according to parameters of the battery assembly. The electrically connected battery string may be finally mounted in the frame 120, thereby obtaining a battery assembly.

It should be noted that the first preset number and the second preset number may be specifically determined according to parameters of the battery pack.

In an embodiment of the present invention, a method for manufacturing a single crystal silicon wafer includes: preparing a monocrystalline silicon rod with a preset crystal orientation by using seed crystals with the preset crystal orientation; performing a squaring operation on the single crystal silicon rod along a direction parallel to the axis of the single crystal silicon rod; and determining the cutting direction of the single crystal silicon rod according to the preset crystal orientation and the target crystal orientation, and cutting the single crystal silicon rod along the cutting direction to obtain the single crystal silicon wafer with the target crystal orientation. According to the method, the silicon single crystal rod with the preset crystal orientation is used, and the silicon single crystal rod is cut along the cutting direction determined according to the preset crystal orientation and the target crystal orientation, so that when the silicon single crystal rod is cut, a diamond wire of a slicing machine can be used for obliquely cutting the silicon single crystal rod along the cutting direction, a silicon single crystal wafer with a larger size and a target crystal orientation is obtained under the condition that the size of the silicon single crystal rod is not increased, the quality of the large-size silicon single crystal wafer is improved, and the production cost and the preparation difficulty of the large-size silicon single crystal wafer are reduced.

In addition, the prepared monocrystalline silicon wafer can be used for preparing a battery piece and a battery component, the monocrystalline silicon wafer has larger size and higher quality, so that the power of the battery component can be improved, and meanwhile, the cost of the monocrystalline silicon wafer is lower, so that the production cost of the solar battery is also reduced.

It should be noted that, for simplicity of description, the method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the embodiments are not limited by the order of acts described, as some steps may occur in other orders or concurrently depending on the embodiments. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred and that no particular act is required to implement the embodiments of the application.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.