Pre-lithiation cavity and pole piece pre-lithiation equipment

Abstract

The invention discloses a pre-lithiation cavity and pole piece pre-lithiation equipment. The pre-lithiation cavity comprises a pre-lithiation box body, an electrolyte layer and a supporting structure, the electrolyte layer and the pre-lithiation box body define a containing space, and the surface, opposite to the containing space, of the electrolyte layer is used for making contact with an active substance coating of a pole piece strip; the supporting structure is arranged in the accommodating space and comprises a supporting main body and a plurality of supporting parts, and the supporting main body is mounted on the pre-lithium box body; the multiple supporting parts are arranged at intervals, and connecting sections are formed on the parts, away from the electrolyte layer, of the supporting parts and used for connecting the supporting body; the part, close to the electrolyte layer, of each supporting part forms a supporting section, the supporting section is provided with a supporting end face, and the supporting end face abuts against the electrolyte layer. According to the invention, the electrolyte layer is supported by the plurality of supporting parts, so that the flatness of the electrolyte layer is improved, the acting force of the electrolyte layer on the active substance coating is more uniform, and the attachment is tighter, so that Li < + > can more uniformly penetrate through the electrolyte layer, and the pre-lithium effect is improved.

Description

Technical Field

[0001] The present application relates to the field of battery processing technology, and in particular to a pre-lithiation cavity and a pole piece pre-lithiation device. Background Art

[0002] In recent years, industry insiders have been continuously exploring methods for pre-lithiation of negative electrode sheets to solve the problem of low coulombic efficiency of lithium batteries during the first charge and discharge process, while improving battery energy density and cycle life.

[0003] Among them, the method of pre-lithiation treatment by contacting the active material coating of the negative electrode can achieve a good pre-lithiation effect. However, when using the pre-lithiation method in which the electrolyte layer is in contact with the active material coating, since the active material coating and the electrolyte layer have a certain contact area, it is difficult to maintain the uniformity of the force applied by the electrolyte layer to the active material coating, which affects the pre-lithiation effect. Summary of the Invention

[0004] The embodiments of the present application provide a pre-lithiation cavity and a pole piece pre-lithiation device, which can solve the problem of uneven force exerted by the electrolyte layer on the active material coating, thereby affecting the pre-lithiation effect.

[0005] In a first aspect, the present application provides a pre-lithium cavity, comprising a pre-lithium box, an electrolyte layer, and a support structure.

[0006] The electrolyte layer is installed in the pre-lithium box, and the electrolyte layer and the pre-lithium box are surrounded to form a receiving space, and the surface of the electrolyte layer facing away from the receiving space is used to contact the active material coating of the electrode strip;

[0007] A support structure is provided in the accommodation space, the support structure comprising a support body and a plurality of support parts, and the support body is installed in the pre-lithium box;

[0008] The plurality of support portions are arranged at intervals, and a portion of each support portion away from the electrolyte layer forms a connecting segment, and the connecting segment is used to connect the support body;

[0009] A portion of each support portion close to the electrolyte layer forms a support segment. The support segment has a support end surface. The support end surface contacts the electrolyte layer to provide support for the electrolyte layer.

[0010] In some embodiments, the thickness of the electrolyte layer is A1, and the width of the support end surface is B1; wherein A1 and B1 satisfy: 0.2≤B1 / A1≤1.0.

[0011] In some embodiments, the width of the supporting end surface is B1, and the width of the connecting section is B2; wherein the supporting portion satisfies the following condition: 1.0≤B2 / B1≤2.5; preferably, satisfies: 1.5≤B2 / B1≤2.5.

[0012] In some embodiments, the width of the connecting segment is B2, and the distance between two adjacent connecting segments is C2; wherein, 0.5≤C2 / B2≤1.5 is satisfied.

[0013] In some embodiments, the support body and the support portion are stacked along the thickness direction of the electrolyte layer;

[0014] The supporting portion is a first strip-shaped supporting rib, the supporting body includes a plurality of second strip-shaped supporting ribs, and the plurality of first supporting ribs and the plurality of second supporting ribs are stacked and staggered to form a grid-like structure; or, the supporting portion is a supporting column, the supporting body is a supporting grid, and each of the supporting columns is arranged at the intersection of the supporting grid.

[0015] In some embodiments, the supporting body includes a plurality of connecting bars, and the connecting bars are connected to the side wall surface of the connecting section;

[0016] The support portion is a strip-shaped first support rib, and two adjacent first support ribs are connected by a plurality of the connecting strips; or, the support portion is a support column, and two adjacent support columns are connected by one connecting strip.

[0017] In some embodiments, the plurality of support portions are integrally provided with the support body; or, the plurality of support portions are detachably mounted on the support body.

[0018] In some embodiments, the supporting end surface is a plane or a curved surface.

[0019] In a second aspect, the present application provides a pole piece pre-lithiation device, comprising a pre-lithiation unit, wherein the pre-lithiation unit comprises a pre-lithiation platform and the pre-lithiation cavity as described above;

[0020] The pre-lithium platform is used to carry the pole piece strip, the pre-lithium cavity is arranged corresponding to the pre-lithium platform, and the electrolyte layer is used to contact the active material coating of the pole piece strip on the pre-lithium platform.

[0021] In some embodiments, the thickness direction of the electrolyte layer is the direction of gravity; the electrolyte layer is located above the electrode strip and contacts the active material coating; or, the electrolyte layer is located below the electrode strip and contacts the active material coating.

[0022] Based on the pre-lithiation cavity and the electrode pre-lithiation equipment of the embodiment of the present application, the flatness of the electrolyte layer is improved by the support of multiple supporting parts during the contact between the electrolyte layer and the active material coating, so that the force of the electrolyte layer acting on the active material coating is more uniform, and the electrolyte layer and the active material coating are more closely fitted, thereby making Li + It can pass through the electrolyte layer more evenly, improving the pre-lithiation effect. In addition, due to the presence of the support structure, the molten salt and lithium source in the lower area adjacent to the electrolyte layer in the accommodation space are less disturbed by the molten salt and lithium source in the upper area, and under the guidance of multiple support parts, the molten salt and lithium source can flow more smoothly to the electrolyte layer, thereby also improving the pre-lithiation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic structural diagram of a pre-lithium chamber according to an embodiment of the present application;

[0025] Figure 2 This is a side view schematic diagram of the support structure in contact with the electrolyte layer according to an embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of the main structure of an embodiment of the present application in which the first supporting ribs and the second supporting ribs are staggered;

[0027] Figure 4 This is a schematic diagram of the main structure of a support column connected to the intersection of the support grid according to an embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the main structure of a connecting strip connected to a supporting column according to an embodiment of the present application;

[0029] Figure 6 This is a side view schematic diagram of the structure of a connecting strip connected to a support column according to an embodiment of the present application;

[0030] Figure 7 This is a schematic structural diagram of a pole piece pre-lithiation device according to an embodiment of the present application;

[0031] Figure 8 This is a structural schematic diagram of a pole piece pre-lithiation device according to another embodiment of the present application;

[0032] Figure 9This is a structural schematic diagram of an embodiment of the present application in which a sub-box is connected to the side wall of the main box.

[0033] Reference numerals:

[0034] 10. Electrode pre-lithiation equipment;

[0035] 100. Pre-lithium unit; 110. Pre-lithium platform;

[0036] 120, pre-lithium chamber; 120a, accommodation space; 121, electrolyte layer; 123, pre-lithium box; 120a, accommodation space; 1231, main box; 1232, sub-box; 124, support structure; 1241, support body; 1242, support portion; 1214, connecting section; 1224, support section; 1240, support end surface; 124a, first support rib; 124b, second support rib; 124c, support column; 124d, support grid; 124e, connecting bar; 126, liquid level detector;

[0037] 310, unwinding assembly; 320, winding assembly; 20, electrode strip. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0039] The present invention provides a pre-lithium cavity, which is used to contact the active material coating of the pole piece strip and perform pre-lithium treatment to supplement Li + .like Figure 1 , which is a structural diagram of a pre-lithium chamber 120 according to an embodiment of the present application. The pre-lithium chamber 120 includes a pre-lithium box 123 , an electrolyte layer 121 and a support structure 124 .

[0040] The electrolyte layer 121 is installed in the pre-lithium box 123, and the electrolyte layer 121 and the pre-lithium box 123 are surrounded to form a receiving space 120a, which is used to receive the molten salt and the lithium source R. The electrolyte layer 121 has a pre-lithium surface facing away from the receiving space 120a. The pre-lithium surface of the electrolyte layer 121 is used to contact the active material coating of the electrode strip 20, so that when the pre-lithium cavity 120 is loaded with a pre-lithium voltage, the Li in the receiving space 120a is heated. + The active material coating is embedded through the electrolyte layer 121 to achieve pre-lithiation treatment of the active material coating.

[0041] In this application, there is no strict limitation on the types of solid electrolyte, molten salt, and lithium source. Under the guidance of this application, those skilled in the art can select any suitable solid electrolyte, molten salt, and lithium source according to actual needs.

[0042] For example, the material of the solid electrolyte includes Li7La3Zr2O 12 、Li 6.4 La3Ta 0.6 Zr 1.4 O 12 、LiTi2(PO4)3、Li 14 At least one of Zn(GeO4)4, Li2S-P2S5, LiBH4, LiI, Li3PO4, Li2B4O7, lithium nitride phosphate, a lithium ion solid electrolyte containing a polymer, and a lithium ion solid electrolyte doped with β-Al2O3.

[0043] Exemplarily, the molten salt includes at least one of LiF, KF, NaF, RbF, CsF, BaF2, LiCl, KCl, NaCl, RbCl, CsCl, BaCl2, LiBr, KBr, NaBr, RbBr, CsBr, BaBr2, LiI, KI, NaI, RbI, CsI, BaI2, LiNO3, KNO3, NaNO3, LiAlCl4, and NaAlCl4.

[0044] Exemplarily, the lithium source includes at least one of a lithium salt and a lithium alloy; the lithium salt includes at least one of LiF, LiCl, LiI, and LiNO3; the lithium alloy includes at least one of a Li-Zn alloy, a Li-Sn alloy, a Li-Bi alloy, a Li-Pb alloy, a Li-Cu alloy, and a Li-Al alloy.

[0045] The electrode strip 20 of the embodiment of the present application can be cut to form a negative electrode after pre-lithium treatment. The embodiment of the present application does not specifically limit the material of the electrode strip 20. All materials used in the field for electrode strip 20 can be applied to the present application. Among them, the active material coating of the electrode strip 20 of the embodiment of the present application can be in the range of 40mm to 400mm in length, 40mm to 200mm in width, and the surface density of the active material coating is 25g / m 2 ~220g / m 2 During the pre-lithium treatment, the electrolyte layer 121 covers the active material coating along the thickness direction of the active material coating and adheres to the surface of the active material coating. The pressure applied by the electrolyte layer 121 to the active material coating is P, and P satisfies 0.1 kg / cm 2 ≤P≤20Kg / cm 2, so that the electrolyte layer 121 and the active material coating are closely attached to each other so that the Li + It can smoothly enter the active material coating layer, and at the same time, prevent the pressure between the electrolyte layer 121 and the active material coating layer from being too high, which may cause the risk of the two being crushed.

[0046] The inventors found that during the pre-lithium treatment process, the electrolyte layer 121 is in contact with the active material coating. Since the active material coating and the electrolyte layer 121 have a certain contact area, it is difficult to maintain the uniformity of the force exerted by the electrolyte layer 121 on the active material coating. For example, due to the influence of gravity, the force exerted on the active material coating by the edge area and the center area of ​​the electrolyte layer 121 is uneven; or the electrolyte layer 121 is deformed during the pre-lithium process and is not tightly attached to the active material coating, which will affect the Li passing through the electrolyte layer 121. + Based on this, the embodiment of the present application sets the pre-lithium box 123 to further include a support structure 124, which provides support for the electrolyte layer 121 and improves the uniformity of the force applied by the electrolyte layer 121 to the active material coating.

[0047] like Figure 1 As shown, the support structure 124 is provided in the accommodation space 120a. The support structure 124 includes a support body 1241 and a plurality of support portions 1242. The support body 1241 is mounted on the pre-lithium box 123. The portion of each support portion 1242 away from the electrolyte layer 121 forms a connecting section 1214, and the portion facing the electrolyte layer 121 forms a supporting section 1224. The connecting section 1214 is connected to the support body 1241. The plurality of support portions 1242 are arranged at intervals. The supporting sections 1224 of the support portions 1242 have support end surfaces 1240 facing the electrolyte layer 121. The support end surfaces 1240 are in contact with the electrolyte layer 121, so that the support body 1241 provides support for the electrolyte layer 121.

[0048] In the pre-lithiation chamber 120 of the embodiment of the present application, the molten salt and the lithium source R in the accommodation space 120a can be immersed around the support body 1241 and the plurality of support parts 1242, thereby + The electrolyte layer 121 can be smoothly entered by the support of the multiple support parts 1242. In the process of contact between the electrolyte layer 121 and the active material coating, the flatness of the electrolyte layer 121 is improved, so that the force exerted by the electrolyte layer 121 on the active material coating is more uniform, and the electrolyte layer 121 and the active material coating are more closely attached, thereby making the Li +It can pass through the electrolyte layer 121 more evenly, improving the pre-lithiation effect. In addition, due to the presence of the support structure 124, the molten salt and lithium source R in the lower area adjacent to the electrolyte layer 121 in the accommodating space 120a are less disturbed by the molten salt and lithium source R in the upper area. Under the guidance of the multiple support parts 1242, the molten salt and lithium source R can flow more smoothly to the electrolyte layer 121, thereby also improving the pre-lithiation effect.

[0049] In some embodiments, as Figure 1 As shown, the pre-lithium box 123 includes a main box 1231 and a sub-box 1232 connected to the main box 1231. The volume of the main box 1231 is larger than that of the sub-box 1232. The interior of the main box 1231 is used to accommodate a large amount of molten salt and lithium source R, and the interior of the sub-box 1232 can be used to accommodate a small amount of molten salt and lithium source R. The electrolyte layer 121 is provided at the front end of the main box 1231. The electrolyte layer 121 and the main box 1231 are enclosed to form a receiving space 120a. The support structure 124 is provided in the receiving space 120a, and the support body 1241 is installed on the main box 1231. When the molten salt and lithium source R inside the main box 1231 are consumed, the molten salt and lithium source R in the sub-box 1232 can be supplied to the main box 1231 to replenish the consumed molten salt and lithium source R in the main box 1231 in a timely manner.

[0050] The molten salt and lithium source R can be injected into the main box 1231 through the sub-box 1232, guiding the molten salt and lithium source R to enter the main box 1231 more smoothly, reducing the amount of bubbles mixed into the molten salt and lithium source R in the main box 1231, and avoiding the bubbles from affecting the pre-lithiation process (Li + The sub-box 1232 injects molten salt and lithium source R into the accommodating space 120a in the upper area of ​​the accommodating space 120a of the main box 1231 to reduce the interference of the molten salt and lithium source R flowing in the upper area on the molten salt and lithium source R in the lower area.

[0051] In some embodiments, the pre-lithium chamber 120 further includes a heating layer (not shown in the figure), which may be provided in the main box 1231 to heat the molten salt and the lithium source R in the main box 1231. Alternatively, the number of heating layers is multiple, wherein a portion of the heating layers is provided in the main box 1231 to heat the molten salt and the lithium source R in the main box 1231, and another portion of the heating layers is provided in the sub-box 1232 to heat the molten salt and the lithium source R in the sub-box 1232. The heating layer provided outside the main box 1231 can simultaneously heat the molten salt and the lithium source R in the upper and lower areas of the accommodating space 120a to improve the uniformity of melting of the molten salt and the lithium source R in the accommodating space 120a.

[0052] In some embodiments, as Figure 2As shown, the thickness of the electrolyte layer 121 is A1, the width of the support end face 1240 is B1, and A1 and B1 satisfy: 0.2≤B1 / A1≤1.0. For example, B1 / A1 can be 0.20, 0.25, 0.32, 0.40, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or any range of the above two. By selecting A1 and B1 to meet the above conditional formula, it is possible to ensure that the electrolyte layer 121 has good support strength while minimizing the effective contact area between the support end face 1240 of the support portion 1242 and the electrolyte layer 121. That is, the support portion 1242 can play a supporting role, preventing the support portion 1242 from piercing and damaging the electrolyte layer 121, and can also increase the spacing between the support end faces 1240 of two adjacent support portions 1242 as much as possible to leave more space for the molten salt and the lithium source R to contact the electrolyte layer 121, thereby increasing the pre-lithiation rate.

[0053] In some embodiments, the thickness A1 of the electrolyte layer 121 ranges from 1 mm to 6 mm. For example, A1 can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, or any range thereof.

[0054] In some embodiments, the width of the support end surface 1240 is B1, and the width of the connecting segment 1214 is B2. B1 and B2 satisfy 1.0≤B2 / B1≤2.5. For example, B2 / B1 can be 1.0, 1.2, 1.5, 1.9, 2.2, 2.5, or any range thereof. By selecting B1 and B2 to satisfy the above conditional expression, the dimensions of the two ends of the support portion 1242 can be set to be equal. Alternatively, the contact area of ​​the connecting segment 1224 of the support portion 1242 used to connect to the support body 1241 is larger, so that the support portion 1242 and the support body 1241 have better connection structural strength, preventing the support portion 1242 from breaking. At the same time, the size of the support end surface 1240 of the support portion 1242 is smaller, and the overall area of ​​the support end surfaces 1240 of the multiple support portions 1242 covering the electrolyte layer 121 is small, so that the surface of the electrolyte layer 121 can have more area for contact with the molten salt lithium source.

[0055] In some embodiments, when the widths of the two ends of the support portion 1242 are equal (B1=B2), the width of the support portion 1242 remains constant along the thickness direction of the electrolyte layer 121, i.e., the support portion 1242 is of constant diameter. When the width B2 of the end of the support portion 1242 used for connection to the support body 1241 is larger, the width of the support portion 1242 gradually decreases along the thickness direction of the electrolyte layer 121, i.e., the support portion 1242 is of variable diameter. This allows the molten salt and the lithium source R to smoothly enter the gap between two adjacent support portions 1242, allowing the molten salt and the lithium source R to more efficiently contact the surface of the electrolyte layer 121.

[0056] In some embodiments, the width of the connecting segment 1214 of the support portion 1242 is B2, and the spacing between two adjacent connecting segments is C2, C2 and B2 satisfy 0.5≤C2 / B2≤1.5. For example, C2 / B2 can be 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, or any range thereof. By selecting C2 and B2 to satisfy the above conditional expression, it is convenient to control the coverage area of ​​the electrolyte layer 121 covered by the plurality of support portions 1242 as a whole within an appropriate range, so that the surface of the electrolyte layer 121 has an appropriate area in contact with the molten salt and the lithium source R, and prevent the plurality of support portions 1242 from having too little contact area with the electrolyte layer 121 as a whole, resulting in insufficient supporting force.

[0057] In some embodiments, as Figure 3 and Figure 4 As shown, the support portion 1242 may be a strip-shaped first support rib 124a, or the support portion 1242 may be a column-shaped support column 124c.

[0058] When the support portion 1242 is a strip-shaped first support rib 124a, the first support rib 124a has a length direction M and a width direction N. Multiple first support ribs 124a are arranged side by side along the width direction N. The size of the first support rib 124a along the length direction M is larger than the size along the width direction N. The width B1 and width B2 of the support portion 1242 are the sizes of the first support rib 124a along the width direction N. The spacing C2 between the connecting sections 1214 of two adjacent support portions 1242 is the size of the two adjacent first support ribs 124a in the direction in which they are arranged side by side.

[0059] When the support portion 1242 is a columnar support column 124c, the support column 124c has a length direction (ie, an axial direction of the support column 124c, for example Figure 4 The length direction of the support column 124c is parallel to the thickness direction H of the electrolyte layer 121, and the support column 124c has a cross section along its length direction. The width B1 and width B2 of the support portion 1242 are the diameters of the cross section of the support column 124c along its length direction, wherein the outer contour of the cross section may be circular, elliptical or polygonal. The diameter of a circular cross section is directly the diameter of the outer contour of the circular cross section, the diameter of an elliptical cross section is directly the length of the major semi-axis of the outer contour of the elliptical cross section, and the diameter of a polygonal cross section is directly the diameter of the circumscribed circle of the outer contour of the polygonal cross section. The spacing C2 between two adjacent support portions 1242 is the spacing between two adjacent support columns 124c in the direction perpendicular to the length of the support column 124c (for example Figure 4 horizontal direction).

[0060] In some embodiments, the support end surface 1240 is a plane, or the support end surface 1240 is a convex arc surface, so that the support portion 1242 can stably support the electrolyte layer 121 and further reduce the effective contact area between the support end surface 1240 and the electrolyte layer 121 .

[0061] In some embodiments, the support body 1241 and the support portion 1242 are stacked along the thickness direction H of the electrolyte layer 121, that is, the end surface of the connecting section 1214 of the support portion 1242 facing away from the electrolyte layer 121 is connected to the support body 1241. Figure 3 As shown, when the support portion 1242 is a strip-shaped first support rib 124a, the support body 1241 includes a plurality of strip-shaped second support ribs 124b, and the plurality of first support ribs 124a and the plurality of second support ribs 124b are staggered to form a grid-like structure, and the molten salt and lithium source R pass through the gap between two adjacent second support ribs 124b and enter the gap between two adjacent first support ribs 124a, and then reach the electrolyte layer 121. By cross-connecting multiple second support ribs 124b with multiple first support ribs 124a, the first support ribs 124a can have good connection stability with the second support ribs 124b, while minimizing the contact area between each first support rib 124a and the second support rib 124b, so that the molten salt and the lithium source R are in contact with the solid electrolyte as much as possible. In addition, each second support rib 124b is connected to multiple first support ribs 124a, and the supporting force on the multiple first support ribs 124a is more uniform, thereby providing support for the electrolyte layer 121 and making the force of the electrolyte layer 121 acting on the active material coating more uniform.

[0062] In some embodiments, the support body 1241 and the support portion 1242 are stacked along the thickness direction of the electrolyte layer 121, that is, the end surface of the connecting section 1214 of the support portion 1242 facing away from the electrolyte layer 121 is connected to the support body 1241. Figure 4As shown, when the support portion 1242 is a support column 124c, the support body 1241 is a cross-shaped support grid 124d. Each support column 124c is arranged at the intersection of the support grid 124d. The molten salt and the lithium source R pass through the grid holes S of the support grid 124d and enter the gap between two adjacent support columns 124c, thereby reaching the electrolyte layer 121. The support column 124c connected to the intersection of the support grid 124d can just avoid the grid holes S of the support grid 124d, allowing the molten salt and the lithium source R to smoothly enter between the two adjacent support columns 124c. The intersection of the support grid 124d can also provide support for the support column 124c in the length direction (i.e., the axial direction) of the support column 124c, so that the support end surface 1240 of the support column 124c is more closely attached to the surface of the electrolyte layer 121. The support end surface 1240 of the support column 124c is smaller in size, so that the surface area of ​​the electrolyte layer 121 has more area for contact with the molten salt and the lithium salt.

[0063] In some embodiments, as Figure 5 and Figure 6 As shown, the support body 1241 includes a plurality of connecting bars 124e, each connecting bar 124e is connected to the side wall surface of the connecting section 1214 of two adjacent support parts 1242, so that the connecting bars 124e and the connecting section 1214 of the support part 1242 are in the same plane perpendicular to the thickness direction H of the electrolyte layer 121. In this case, one possible way is that when the support part 1242 is a support column 124c, two adjacent support columns 124c are connected by a connecting bar 124e, as shown in FIG. Figure 5 and Figure 6 As shown; another possible embodiment, when the support portion 1242 is a strip-shaped first support rib 124a, two adjacent first support ribs 124a are connected by multiple connecting bars 124e, and the molten salt and lithium source R pass through the spaces between the adjacent multiple first support ribs 124a and the multiple connecting bars 124e to reach the electrolyte layer 121 (not shown). In this way, the material consumption of the support body 1241 can be reduced, and the multiple support portions 1242 can also provide uniform and stable support for the electrolyte layer 121.

[0064] In some embodiments, multiple support parts 1242 are integrally arranged with the support body 1241. For example, the support parts 1242 and the support body 1241 are integrally arranged by injection molding, welding, etc., so that the support parts 1242 and the support body 1241 have good connection structural strength, and the support parts 1242 are not easy to break relative to the support body 1241.

[0065] In some embodiments, multiple support portions 1242 can be detachably mounted on the support body 1241. For example, a hole or groove can be opened in one of the support body 1241 or the support portion 1242, and the other of the support body 1241 or the support portion 1242 is inserted into the hole or groove, and the two are interference fit to snap the support portion 1242 into engagement with the support body 1241.

[0066] In some embodiments, in the direction in which two adjacent support portions 1242 are arranged side by side, the spacing C2 between the connecting sections of the two adjacent support portions 1242 and the spacing L1 between the support portion 1242 located at the edge and the inner wall surface of the pre-lithium box 123 are equal, so that the molten salt and the lithium source R can evenly pass through the support structure 124 into the electrolyte layer 121, and multiple support portions 1242 can be evenly distributed, thereby providing more uniform support for the electrolysis support 121.

[0067] like Figure 7 As shown, the embodiment of the present application also provides a pole piece pre-lithiation device 10, the pole piece pre-lithiation device 10 includes a pre-lithiation unit 100, the pre-lithiation unit 100 includes a pre-lithiation platform 110 and the pre-lithiation cavity 120 as described above, the pre-lithiation platform 110 is used to carry the pole piece strip 20, the pre-lithiation cavity 120 is arranged corresponding to the pre-lithiation platform 110, the electrolyte layer 121 is used to contact the active material coating of the pole piece strip 20 on the pre-lithiation platform 110, and the pre-lithiation platform 110 provides support for the pole piece strip 20 so that the pole piece strip 20 is flat on the pre-lithiation platform 110, and the electrolyte layer 121 of the pre-lithiation cavity 120 is moved to contact the active material coating of the pole piece strip 20, the pre-lithiation platform 110 and the electrolyte layer 121 are clamped on both sides of the pole piece strip 20 from both sides, so that the electrolyte layer 121 and the active material coating fit more closely, thereby improving the pre-lithiation effect.

[0068] In some embodiments, the thickness direction of the electrolyte layer 121 is the gravity direction, wherein at least part of the molten salt and the lithium source R are located above the electrolyte layer 121 in the gravity direction, so that the molten salt and the lithium source R are deposited on the surface of the electrolyte layer 121 under the action of gravity, so that the molten salt and the lithium source R can smoothly pass through the support structure 124 and be replenished in time to contact the electrolyte layer 121.

[0069] In some embodiments, the electrolyte layer 121 is located above the electrode strip 20 and contacts the active material coating, and the support structure 124 is also located above the electrolyte layer 121 to provide support for the electrolyte layer 121. Figure 7As shown, a sub-box 1232 can be set on the upper side of the main box 1231. When adding materials (molten salt and lithium source R), the liquid enters the main box 1231 from the sub-box 1232 to ensure smooth addition of the liquid. The sub-box 1232 acts as a buffer to avoid introducing too many bubbles that affect the pre-lithium effect. At this time, the sub-box 1232 and the main box 1231 can be connected through a linear pipe. The molten salt and lithium source R in the main box 1231 are above the electrolyte layer 121, wherein the linear pipe can be a linear pipe that is angled with the horizontal direction.

[0070] In some embodiments, as Figure 8 and Figure 9 As shown, the electrolyte layer 121 is located below the electrode strip 20 and in contact with the active material coating. The support structure 124 is also located below the electrolyte layer 121 to provide support for the electrolyte layer 121. At this time, in order to ensure that the molten salt and lithium source R completely cover the electrolyte layer 121, the liquid level of the sub-tank 1232 must be higher than the liquid level in the main tank 1231 to ensure that the main tank 1231 is always fully filled and to prevent gas from entering the main tank 1231, affecting the contact between the molten salt and lithium source R and the solid electrolyte layer 121, and further affecting pre-lithiation. At this time, the sub-box 1232 can be located on the side of the main box 1231, and the sub-box 1232 is connected to the main box 1231 through a zigzag pipe or a straight pipe. For example, the zigzag pipe can be an L-shaped pipe or a U-shaped pipe, and the straight pipe connection can be a straight pipe that is angled with both the horizontal and vertical directions. The molten salt and lithium source R in the main box 1231 are below the electrolyte layer 121, and the liquid level of the molten salt and lithium source R in the sub-box 1232 is higher than the liquid level of the molten salt and lithium source R in the main box 1231.

[0071] In some embodiments, the electrode pre-lithiation equipment 10 also includes a preheating platform 210, and the preheating platform 210 and the pre-lithiation platform 110 are arranged at intervals along a preset conveying direction X. The preheating platform 210 and the pre-lithiation platform 110 jointly provide support for the electrode strip 20, and are used to adjust the position of the electrode strip 20 so that the electrode strip 20 can move along the preset conveying direction X. The preheating platform 210 can heat the active material coating of the electrode strip 20 carried thereon, so as to preset the active material coating and transfer it to the pre-lithiation platform 110 for subsequent pre-lithiation treatment.

[0072] In some embodiments, the electrode pre-lithiation equipment 10 may include a group of pre-lithiation units 100 and a preheating platform 210 , and a pre-lithiation unit 100 sequentially performs pre-lithiation treatment on multiple active material coatings of the electrode strip 20 .

[0073] In some embodiments, the electrode pre-lithiation equipment 10 may include multiple groups of pre-lithiation units 100, which are arranged at intervals along a preset conveying direction X. The active material coating of the electrode strip 20 is pre-lithiated by the multiple groups of pre-lithiation units 100 to improve the pre-lithiation efficiency.

[0074] Optionally, see Figure 1 The electrode pre-lithiation equipment 10 may include multiple groups of pre-lithiation units 100 and a group of preheating platforms 210. After being preheated by the preheating platforms 210, the active material coatings of the electrode strip 20 pass through the multiple pre-lithiation units 100 in sequence. Each time, the active material coating contacts the pre-lithiation surface of the electrolyte layer 121 of at least one pre-lithiation unit 100 for at least one pre-lithiation treatment, thus completing the pre-lithiation treatment of the active material coating. In addition, along the preset conveying direction X, the spacing between the preheating platform 210 and the pre-lithiation platform 110, as well as the spacing between two adjacent pre-lithiation platforms 110, are equal.

[0075] In some embodiments, as Figure 7 As shown, the electrode pre-lithiation equipment 10 may include multiple groups of pre-lithium units 100 and multiple preheating platforms 210, which can divide the multiple active material coatings of the electrode strip 20 into one group, move the multiple active material coatings of the same group to a one-to-one correspondence with the multiple preheating platforms 210 and preheat, and then move along the preset conveying direction X to a one-to-one correspondence with the multiple pre-lithium units 100. After the electrolyte layers 121 of the multiple pre-lithium units 100 are pre-lithium treated one-to-one with the multiple active material coatings of the same group, the pre-lithium treatment of the multiple active material coatings of the group is completed. While the pre-lithium treatment of the multiple active material coatings of the group is being carried out, the multiple active material coatings of the next group are moved to a one-to-one correspondence with the multiple preheating platforms 210 for preheating, and multiple groups of active material coatings are moved in sequence for preheating and pre-lithium treatment. Among them, the spacing between two adjacent preheating platforms 210 and the spacing between two adjacent pre-lithium platforms 110 can be selected according to the spacing between two adjacent active material coatings.

[0076] When there are multiple pre-lithium units 100, the multiple pre-lithium units 100 include multiple pre-lithium platforms 110 and multiple pre-lithium cavities 120, wherein the multiple pre-lithium platforms 110 are arranged in sequence along the preset conveying direction X, that is, the pre-lithium platform 110 has a carrying surface for carrying the electrode strip 20, and the carrying surfaces of the multiple pre-lithium platforms 110 are distributed on the same straight line and in the same plane, so that the electrode strip 20 can be transported in a straight direction to prevent the position of the electrode strip 20 from being offset.

[0077] In some embodiments, a plurality of pre-lithiation cavities 120 are provided on the same side of a plurality of pre-lithiation platforms 110 along a direction perpendicular to a preset conveying direction X. In some embodiments, when a plurality of active material coatings of the electrode strip 20 are provided on the same side of the current collector substrate 21, the plurality of active material coatings are moved along the preset conveying direction X, and a pre-lithiation treatment is performed on each active material coating, thereby completing the single-sided pre-lithiation treatment of the electrode strip 20. In some other embodiments, when a plurality of active material coatings of the electrode strip 20 are distributed on opposite sides of the current collector substrate 21, the electrode strip 20 is moved along the preset conveying direction X, and after all the plurality of active material coatings on one side of the electrode strip 20 are pre-lithiation treated, the electrode strip 20 is rewound, and the electrode strip 20 is moved again along the preset conveying direction X, and after all the plurality of active material coatings on the other side of the electrode strip 20 are pre-lithiation treated, the double-sided pre-lithiation treatment of the electrode strip 20 is completed. Optionally, the preset transport direction X is horizontal, and the pre-lithiation surface of the electrolyte layer 121 is a plane parallel to the horizontal direction. In this case, the pre-lithiation cavities 120 of the multiple pre-lithiation units 100 can be vertically arranged above the multiple pre-lithiation platforms 110; or, the pre-lithiation cavities 120 of the multiple pre-lithiation units 100 can be vertically arranged below the multiple pre-lithiation platforms 110. The multiple pre-lithiation cavities 120 arranged on the same side of the multiple pre-lithiation platforms 110 can be arranged side by side in a direction parallel to the preset transport direction X.

[0078] In some embodiments, as Figure 8 As shown, along the direction perpendicular to the preset conveying direction X, a part of the pre-lithium cavities 120 are arranged on the same side of the multiple pre-lithium platforms 110, and the other part of the pre-lithium cavities 120 are arranged on the other side of the multiple pre-lithium platforms 110. In this way, double-sided pre-lithiation can be performed. When the multiple active material coatings of the electrode strip 20 are distributed on the opposite sides of the current collector substrate 21, the electrode strip 20 is directly moved along the preset conveying direction X, and the pre-lithium cavities 120 distributed on the opposite sides of the multiple pre-lithium platforms 110 can perform pre-lithiation treatment on the active material coatings on the corresponding side, thereby improving the pre-lithiation efficiency.

[0079] In some more specific embodiments, when a portion of the pre-lithium cavities 120 are disposed on one side of the plurality of pre-lithium platforms 110 and another portion of the pre-lithium cavities 120 are disposed on the other side of the plurality of pre-lithium platforms 110, the pre-lithium cavities 120 located on the upper and lower sides of the plurality of pre-lithium platforms 110 may be arranged crosswise, that is, each pre-lithium unit 100 has a pre-lithium cavity 120 and a pre-lithium platform 110, and the pre-lithium cavities 120 of two adjacent pre-lithium units 100 are disposed on opposite sides of the pre-lithium platform 110. Optionally, the preset transport direction X is a horizontal direction, and the pre-lithium surface of the electrolyte layer 121 is a plane parallel to the horizontal direction. In this case, the pre-lithium cavities 120 of a portion of the pre-lithium units 100 are disposed vertically above the plurality of pre-lithium platforms 110, and the pre-lithium cavities 120 of the remaining portion of the pre-lithium units 100 are disposed vertically below the plurality of pre-lithium platforms 110.

[0080] In some more specific embodiments, when a portion of the pre-lithium cavities 120 are arranged on one side of multiple pre-lithium platforms 110 and another portion of the pre-lithium cavities 120 are arranged on the other side of the multiple pre-lithium platforms 110, it is also possible that n consecutive pre-lithium cavities 120 are all arranged on the same side of the multiple pre-lithium platforms 110, and n adjacent consecutive pre-lithium cavities 120 are all arranged on the other side of the multiple pre-lithium platforms 110. In this way, n consecutive surfaces to be pre-lithiumed on the same side can be pre-lithiumed at the same time, and then the corresponding surfaces to be pre-lithiumed on the other side can be pre-lithiumed at the same time to complete double-sided pre-lithiation.

[0081] In some embodiments, the pre-lithium cavity 120 further includes a liquid level detector 126, which is installed in the pre-lithium box 123. The liquid level detector 126 is arranged above the electrolyte layer 121 along the direction of gravity. The liquid level detector 126 is used to obtain the liquid level of the molten salt and the lithium source R in the pre-lithium cavity 120, and generate a liquid level signal. According to the liquid level signal, the molten salt and the lithium source R are replenished into the main box 1231 to prevent the amount of the molten salt and the lithium source R in the main box 1231 from being too small, resulting in the molten salt and the lithium source R failing to fully cover the electrolyte layer 121. When the support structure 124 is located above or below the electrolyte layer 121, the liquid level detector 126 is located above the support structure 124 to detect the liquid level of the molten salt and the lithium source R between the support structure 124 and the electrolyte layer 121, so as to replenish the molten salt and the lithium source R into the pre-lithium box 123.

[0082] In some embodiments, the electrode pre-lithiation equipment 10 also includes a strip retracting mechanism, which includes an unwinding assembly 310 and a rewinding assembly 320 arranged relatively to each other along a preset conveying direction X. A preheating platform 210 and a pre-lithiation unit 100 are provided between the unwinding assembly 310 and the rewinding assembly 320. The unwinding assembly 310 and the rewinding assembly 320 pull the two ends of the electrode strip 20, thereby tensioning the electrode strip 20 between the unwinding assembly 310 and the rewinding assembly 320, and conveying the electrode strip 20 from the unwinding assembly 310 to the rewinding assembly 320, so that the electrode strip 20 is in a stretched state, so that the active material coating can contact the preheating platform 210 and the pre-lithiation platform 110 in turn in a smooth manner, thereby improving the pre-lithiation effect and preventing the electrode strip 20 from slacking and causing the tape to shift.

[0083] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A pre-lithium chamber, characterized in that: include: Pre-lithium box; An electrolyte layer is installed in the pre-lithium box, and the electrolyte layer and the pre-lithium box are surrounded to form a containing space, and the surface of the electrolyte layer facing away from the containing space is used to contact with the active material coating of the pole piece strip; and A support structure is provided in the accommodation space, the support structure comprises a support body and a plurality of support parts, and the support body is installed in the pre-lithium box; Wherein, a plurality of the support parts are arranged at intervals, and a portion of each support part away from the electrolyte layer forms a connecting section, and the connecting section is used to connect the support body; The portion of each support portion close to the electrolyte layer forms a support segment, and the support segment has a support end surface, and the support end surface is in contact with the electrolyte layer to provide support for the electrolyte layer.

2. The pre-lithium chamber according to claim 1, characterized in that: The thickness of the electrolyte layer is A1, and the width of the support end surface is B1; Among them, A1 and B1 satisfy: 0.2≤B1 / A1≤1.

0.

3. The pre-lithium chamber according to claim 1, characterized in that: The width of the supporting end surface is B1, and the width of the connecting section is B2; Wherein, the support portion meets the following conditions: 1.0≤B2 / B1≤2.5; Preferably, it satisfies: 1.5≤B2 / B1≤2.

5.

4. The pre-lithium chamber according to claim 1, characterized in that: The width of the connecting section is B2, and the distance between two adjacent connecting sections is C2; Among them, it satisfies that 0.5≤C2 / B2≤1.

5.

5. The pre-lithium chamber according to claim 1, characterized in that: The support body and the support portion are stacked along the thickness direction of the electrolyte layer; The support portion is a strip-shaped first support rib, the support body includes a plurality of strip-shaped second support ribs, and the plurality of the first support ribs and the plurality of the second support ribs are stacked and staggered to form a grid-like structure; or, The support part is a support column, the support body is a support grid, and each of the support columns is arranged at the intersection of the support grid.

6. The pre-lithium chamber according to claim 1, characterized in that: The supporting body includes a plurality of connecting bars, and the connecting bars are connected to the side wall surface of the connecting section; The supporting portion is a strip-shaped first supporting rib, and two adjacent first supporting ribs are connected by a plurality of connecting strips; or, The supporting part is a supporting column, and two adjacent supporting columns are connected by a connecting strip.

7. The pre-lithium chamber according to claim 1, characterized in that: A plurality of the support parts are integrally provided with the support body; or, The plurality of support parts are detachably mounted on the support body.

8. The pre-lithium chamber according to any one of claims 1 to 7, characterized in that: The supporting end surface is a plane or a curved surface.

9. A pole piece pre-lithiation device, characterized in that: A pre-lithium unit is included, wherein the pre-lithium unit includes a pre-lithium platform and a pre-lithium cavity as described in any one of claims 1 to 8; The pre-lithium platform is used to carry the pole piece strip, the pre-lithium cavity is arranged corresponding to the pre-lithium platform, and the electrolyte layer is used to contact the active material coating of the pole piece strip located on the pre-lithium platform.

10. The electrode pre-lithiation equipment according to claim 9, characterized in that: The thickness direction of the electrolyte layer is the gravity direction; The electrolyte layer is located above the electrode strip and contacts the active material coating; or, The electrolyte layer is located below the pole piece strip and contacts the active material coating.

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