Solid-state battery processing method

Abstract

The present application relates to the technical field of solid-state battery, and discloses a solid-state battery processing method.The solid-state battery comprises a negative electrode sheet and a positive electrode sheet, a solid-state electrolyte layer is arranged between the negative electrode sheet and the positive electrode sheet, the positive electrode sheet comprises a positive electrode body and a positive electrode lug arranged on one side of the positive electrode body, a positive electrode body is extended out of the negative electrode sheet on at least one side of the negative electrode sheet close to the positive electrode lug to form a to-be-glued area, the positive electrode lug is extended out of the negative electrode sheet, and an overlapping area is arranged in the to-be-glued area.The solid-state battery processing method comprises the following steps: placing the positive electrode sheet on the solid-state electrolyte layer;gluing the to-be-glued area, and the starting point of gluing is located in the overlapping area;and forming a support after the glue is solidified, and the support can be arranged between adjacent solid-state electrolyte layers.The solid-state battery processing method effectively reduces the possibility of short circuit in the to-be-glued area, and improves the safety and reliability of the solid-state battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid-state batteries, in particular to a solid-state battery processing method. BACKGROUND

[0002] The full-solid-state battery is a battery using a solid-state electrolyte, and generally adopts a traditional negative electrode large positive electrode small electrode sheet. Therefore, a to-be-glued area is formed in the circumferential direction of the positive electrode sheet. A support is formed by gluing and solidifying the to-be-glued area to solve the problem of breakage of shear force generated between electrode sheets caused by pressing during assembly, thereby causing a short circuit problem.

[0003] In the prior art, due to uneven gluing, the thickness of the glue layer is too large, which causes the positive electrode sheet to protrude locally, which can cause poor contact between the positive electrode sheet and the adjacent solid-state electrolyte after the subsequent cell stacking, thereby increasing the impedance of lithium ion transmission.

[0004] Therefore, there is an urgent need for a solid-state battery processing method to solve the above problems. SUMMARY

[0005] Based on the above, the purpose of the present application is to provide a solid-state battery processing method which effectively reduces the possibility of short circuit of the to-be-glued area and improves the safety and reliability of the solid-state battery.

[0006] To achieve the above purpose, the present application adopts the following technical scheme:

[0007] The solid-state battery processing method comprises a negative electrode sheet and a positive electrode sheet, a solid-state electrolyte layer is arranged between the negative electrode sheet and the positive electrode sheet, the positive electrode sheet comprises a positive electrode body and a positive electrode lug arranged on one side of the positive electrode body, the negative electrode sheet extends out of the positive electrode body on at least one side close to the positive electrode lug to form a to-be-glued area, the positive electrode lug extends out of the negative electrode sheet and is provided with an overlapping area penetrating the to-be-glued area, and the solid-state battery processing method comprises:

[0008] Placing the positive electrode sheet on the solid-state electrolyte layer;

[0009] Gluing the to-be-glued area, and the starting point of gluing is located in the overlapping area, and a support is formed after the glue solidifies, the support can be arranged between adjacent solid-state electrolyte layers.

[0010] The present application has the following advantages:

[0011] The solid-state battery of the present application comprises a negative electrode sheet and a positive electrode sheet, and a solid-state electrolyte layer is arranged between the negative electrode sheet and the positive electrode sheet, the positive electrode sheet comprises a positive electrode body and a positive electrode tab, wherein the negative electrode sheet extends beyond the positive electrode body at least on the side close to the positive electrode tab to form a to-be-glued area, and the positive electrode tab is arranged in the to-be-glued area and extends to the negative electrode sheet. When the above solid-state battery is processed, first, the positive electrode sheet is placed on the solid-state electrolyte layer, then glue is applied to the to-be-glued area, and the glue is used to form a support after curing, and when the solid-state battery is finally pressed, the support can play a certain supporting role on the solid-state electrolyte layer, avoiding the situation that the solid-state electrolyte layer beyond the positive electrode sheet part is broken during pressing and short circuit occurs. Specifically, since the positive electrode tab is not provided with an active material layer and has a relatively small thickness, the starting point of the glue application is set in the overlapping area during the glue application process, so that even if the local glue layer is not flat, it will not cause a large protrusion in the overlapping area, and then after stacking, the problem of poor contact between the positive electrode sheet and the adjacent solid-state electrolyte layer will not occur, and the problem of increased lithium ion transmission impedance will not occur. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the contents of the embodiments of the present application and these drawings.

[0013] Fig. 1 is a schematic view of the relationship between the solid-state battery negative electrode sheet, the positive electrode sheet, the solid-state electrolyte layer and the to-be-glued area;

[0014] Fig. 2 is a schematic view of the solid-state battery processing method provided by the specific embodiment of the present application, which starts to apply glue to the positive electrode sheet in the clockwise direction;

[0015] Fig. 3 is a flowchart of the solid-state battery processing method provided by the specific embodiment of the present application.

[0016] In the drawings:

[0017] 101, to-be-glued area; 102, overlapping area; 110, negative electrode sheet; 120, positive electrode sheet; 121, positive electrode body; 122, positive electrode tab; 130, solid-state electrolyte layer;

[0018] 200, glue gun;

[0019] 300, doctor blade. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters throughout the figures denote the same or like components or elements having the same or similar functions. The embodiments described below are exemplary and intended to provide an explanation of the present application and are not intended to restrict the present application.

[0021] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0022] Unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "over", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0024] The technical solutions of the present application are further illustrated below in conjunction with the drawings and through specific embodiments.

[0025] As Figs. 1-3As shown, the embodiment provides a solid-state battery processing method. The solid-state battery includes a negative electrode sheet 110 and a positive electrode sheet 120, and a solid-state electrolyte layer 130 is arranged between the negative electrode sheet 110 and the positive electrode sheet 120. The positive electrode sheet 120 includes a positive electrode body 121 and a positive electrode tab 122 arranged on one side of the positive electrode body 121. The negative electrode sheet 110 extends beyond the positive electrode body 121 on at least one side close to the positive electrode tab 122 to form a to-be-glued area 101. The positive electrode tab 122 extends beyond the negative electrode current collector 140 and is arranged in an overlapping area 102 of the to-be-glued area 101. The solid-state battery processing method includes: placing the positive electrode sheet 120 on the solid-state electrolyte layer 130; gluing the to-be-glued area 101, and the starting point of the gluing is located in the overlapping area 102. After the glue is cured, a support is formed, and the support can be located between adjacent solid-state electrolyte layers 130.

[0026] The solid-state battery includes a negative electrode sheet 110 and a positive electrode sheet 120, and a solid-state electrolyte layer 130 is arranged between the negative electrode sheet 110 and the positive electrode sheet 120. The positive electrode sheet 120 includes a positive electrode body 121 and a positive electrode tab 122. The negative electrode sheet 110 extends beyond the positive electrode body 121 on at least one side close to the positive electrode tab 122 to form a to-be-glued area 101. The positive electrode tab 122 extends beyond the negative electrode sheet 110 and is arranged in the to-be-glued area 101. When processing the above-mentioned solid-state battery, first, the positive electrode sheet 120 is placed on the solid-state electrolyte layer 130, and at this time, the negative electrode sheet 110 extends beyond the positive electrode body 121 on at least one side close to the positive electrode tab 122. Then, the to-be-glued area 101 is glued. The gluing is used to form a support after the glue is cured. When the solid-state battery is finally pressed, the support can play a certain supporting role for the solid-state electrolyte layer 130, avoiding the situation that the solid-state electrolyte layer 130 is broken during pressing and short-circuiting. Specifically, since the positive electrode tab 122 is not provided with an active material layer and has a relatively small thickness, the starting point of the gluing is arranged in the overlapping area 102 during the gluing process. Even if the local glue layer is not flat, it will not cause a large protrusion in the overlapping area 102, and thus after stacking, the problem that the positive electrode sheet 120 does not contact the adjacent solid-state electrolyte layer 130 well will not occur, and the problem that the lithium ion transmission impedance is increased will not occur.

[0027] Specifically, the positive electrode sheet 120 includes a positive electrode current collector and a positive electrode active material layer, the positive electrode tab 122 can be cut from the positive electrode current collector, or can be a separate conductive piece, and the positive electrode tab 122 is used for transmission of the cell current. Exemplarily, the positive electrode tab 122 has a thickness ranging from 8 μm to 16 μm; the opposite two surfaces of the positive electrode current collector are both provided with the positive electrode active material layer, and thus the thickness of the positive electrode active material layer ranges from 70 μm to 500 μm. That is, the thickness of the positive electrode tab 122 is much smaller than the thickness of the positive electrode active material layer, and thus the starting point of the gluing is located in the overlapping area 102, which can effectively avoid causing the active material area to locally protrude; at the same time, the starting point of the gluing is located in the overlapping area 102, which can also support the positive electrode tab 122, and avoid the problem of the positive electrode tab 122 being broken during pressing due to the positive electrode tab 122 being relatively thin.

[0028] Further, the positive electrode current collector is not particularly limited as long as it has conductivity and does not cause adverse chemical changes in the battery, and for example, stainless steel, aluminum, nickel, titanium, baked carbon, or aluminum or stainless steel treated on the surface with one of carbon, nickel, titanium, silver, etc. can be used. The positive electrode active material layer includes a positive electrode active material, and the positive electrode active material includes nickel-cobalt-manganese ternary material, lithium iron phosphate material, lithium manganese iron phosphate material, etc. The negative electrode sheet 110 includes a negative electrode current collector and a negative electrode active material layer. The negative electrode current collector can be made of copper, stainless steel, nickel, titanium, etc. The negative electrode active material layer includes a negative electrode active material, and the negative electrode active material includes artificial graphite, natural graphite, silicon-based material, etc. The solid-state electrolyte includes sulfide, oxide, and polymer solid-state electrolyte; specifically, the sulfide in the solid-state electrolyte can be Li7P3S11, Li3PS4, or 80Li2S-20P2S5; the polymer solid-state electrolyte can be polyethylene oxide PEO, polyacrylonitrile PAN, polyvinylidene fluoride PVDF, polymethyl methacrylate PMMA, polypropylene oxide PPO, polyvinylidene chloride PVDC, etc.; and the oxide solid-state electrolyte includes lithium oxide, zirconium oxide, lanthanum oxide, etc.

[0029] In this embodiment, the circumferential direction of the negative electrode sheet 110 extends out of the positive electrode body 121, and the end point of the gluing is located in the overlapping area 102. This makes the end point not to cause a large protrusion in the overlapping area 102 even if the glue layer is uneven, and thus does not cause the problem of the positive electrode sheet 120 not being in good contact with the adjacent solid-state electrolyte layer 130 after stacking, and does not cause the problem of increased lithium ion transmission impedance.

[0030] Preferably, the end point of the gluing is coincidentally arranged with the starting point of the gluing, so as to arrange the positive electrode tab 122 to also be provided with a glue layer, increase the strength of the positive electrode tab 122, and avoid the positive electrode tab 122 being broken during pressing.

[0031] Optionally, the ratio of the width of the support extending in the direction away from the positive electrode body 121 to the length of the positive electrode tab 122 extending in the direction away from the positive electrode body 121 is 0.01-0.3. Specifically, it can be 0.1, 0.15, 0.2, 0.25, etc. Illustratively, the width of the support is 0.1-8mm, so as to avoid the width of the support being too large and affecting the subsequent flow. It can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, etc.

[0032] In one embodiment, the gluing includes: starting from the beginning of the overlapping area 102, gluing the to-be-glued area 101 in the clockwise or counterclockwise direction. That is, gluing the to-be-glued area 101 in only one direction. This gluing method has better continuity of glue, so that the consistency of the thickness of the support after curing is better.

[0033] In another embodiment, the gluing includes: starting from the beginning of the overlapping area 102, gluing the to-be-glued area 101 in the clockwise and counterclockwise directions at the same time. That is, gluing in two directions at the same time. This gluing method is more efficient. Optionally, both directions are 180° around the to-be-glued area 101, so that the two directions can complete the gluing at the same time.

[0034] Specifically, the glue gun 200 is used to glue the to-be-glued area 101, and the glue gun 200 is in communication with the glue supply device, or the glue gun 200 stores glue. The glue outlet of the glue gun 200 is adapted to the width of the to-be-glued area 101. Illustratively, the ratio of the width of the glue outlet to the width of the to-be-glued area 101 is 0.6-1, specifically 0.7, 0.8, 0.9, etc., which is beneficial to improve the consistency of the glue in the width direction of the to-be-glued area 101.

[0035] Further, the glue outlet of the glue gun 200 forms an angle with the to-be-glued area 101, and the direction of movement of the glue gun 200 is inclined, which is convenient for the operator to observe the glue outlet. Illustratively, the angle is 10°-80°, specifically 20°, 30°, 40°, 50°, 60°, 70°, etc., and the glue gun 200 moves at a preset speed to ensure that the support formed after the glue solidifies can have a good supporting effect. Illustratively, the preset speed is 40-200mm / s, specifically 50mm / s, 70mm / s, 90mm / s, 110mm / s, 130mm / s, 150mm / s, 170mm / s, 190mm / s, etc. It can be understood that the preset speed is related to the viscosity of the glue, and those skilled in the art can set it according to the actual situation, which is not limited here.

[0036] Preferably, after the glue gun 200 is used to apply glue to the to-be-glued area 101, the glue outside the to-be-glued area 101 is scraped off. This avoids the glue outside the to-be-glued area 101 affecting the normal use of the solid-state battery. The outside of the to-be-glued area 101 includes the surface beyond the positive electrode sheet 120 and the side beyond the negative electrode current collector 140. Accordingly, the scraper 300 can be provided in an L shape.

[0037] Illustratively, the outer diameter of the support is not greater than the outer diameter of the solid-state electrolyte layer 130, so as to avoid the support extending beyond the edge of the negative electrode sheet 110, occupying extra space, and, if the support is folded to the back side of the negative electrode sheet 110, causing the negative electrode sheet 110 and the adjacent positive electrode sheet 120 to not contact well, thereby affecting the normal use of the solid-state battery.

[0038] In this embodiment, after the to-be-glued area 101 is glued, the formed battery cell monomer is solidified, i.e., the battery cell monomer includes the negative electrode sheet 110, the positive electrode sheet 120, the solid-state electrolyte layer 130, and the support located circumferentially around the positive electrode sheet 120.

[0039] Specifically, the glue is provided as a solid-state electrolyte slurry, which has the same material as the solid-state electrolyte layer 130 and plays a role in conducting lithium ions. It can be understood that the solid-state electrolyte slurry has the same material properties as the solid-state electrolyte layer 130 after solidification, i.e., the to-be-glued area 101 can be used as the solid-state electrolyte layer 130, which is conducive to improving the performance of the solid-state battery. The solid-state electrolyte slurry can include sulfide, oxide, and polymer solid-state electrolyte.

[0040] Illustratively, the glue is provided as hot melt glue, and the solidification time of the hot melt glue is about 3 seconds, so that the surface can be solidified, and the battery cell monomer can be stacked after the surface is solidified, thereby improving the processing efficiency. Optionally, the hot melt glue can include polyolefin hot melt glue, ethylene and copolymer hot melt glue, polyester hot melt glue, polyimide hot melt glue, polyurethane hot melt glue, styrene and block copolymer hot melt glue, etc.

[0041] Finally, the plurality of battery cell monomers are stacked in sequence to form a battery cell unit, and the battery cell unit is pressed at a preset pressure to form a solid-state battery. Optionally, the preset pressure is set to 400 Mpa-800 Mpa to ensure that the contact between the positive electrode sheet 120 and the negative electrode sheet 110 can meet the normal discharge of the solid-state battery. The number of stacked battery cell monomers and the preset pressure can be set by those skilled in the art according to actual needs, and are not specifically limited herein.

[0042] It is worth noting that, under the preset pressure, the shrinkage rate of the plurality of supports is greater than or equal to the shrinkage rate of the battery cell unit, so as to ensure that the solid-state electrolyte layer 130 is not damaged due to excessive shrinkage of the support during the pressing process.

[0043] The above description is only preferred embodiments of the present application, and those skilled in the art can make changes in the specific implementation and application range according to the idea of the present application. The content of the description should not be understood as a limitation of the present application.

Claims

1. A method of processing a solid-state battery, characterized by, The solid-state battery comprises a negative electrode sheet (110) and a positive electrode sheet (120), a solid-state electrolyte layer (130) is arranged between the negative electrode sheet (110) and the positive electrode sheet (120), the positive electrode sheet (120) comprises a positive electrode body (121) and a positive electrode tab (122) arranged on one side of the positive electrode body (121), the negative electrode sheet (110) extends outward from the positive electrode body (121) in the circumferential direction to form a to-be-glued area (101), the positive electrode tab (122) extends outward from the negative electrode sheet (110) and is provided with an overlapping area (102) penetrating the to-be-glued area (101), and the solid-state battery processing method comprises the following steps: placing the positive electrode sheet (120) on the solid-state electrolyte layer (130); gluing the to-be-glued area (101), and the starting point and the ending point of gluing are arranged coincidentally and are both located in the overlapping area (102), and a support is formed after the glue solidifies, and the support can be arranged between adjacent solid-state electrolyte layers (130).

2. The solid-state battery processing method of claim 1, wherein, The width of the support along the direction in which the positive electrode tab (122) extends outward from the positive electrode body (121) is 0.01-0.3 times the length of the positive electrode tab (122) extending outward from the positive electrode body (121).

3. The solid-state battery processing method of claim 1, wherein, The gluing comprises the following steps: starting from the starting point located in the overlapping area (102), gluing the to-be-glued area (101) in the clockwise or counterclockwise direction.

4. The solid-state battery processing method of claim 1, wherein, The gluing comprises the following steps: starting from the starting point located in the overlapping area (102), gluing the to-be-glued area (101) in the clockwise and counterclockwise directions at the same time.

5. The solid-state battery processing method of claim 1, wherein, Gluing the to-be-glued area (101) by using a glue gun (200), and the glue outlet of the glue gun (200) is matched with the width of the to-be-glued area (101).

6. The solid-state battery processing method of claim 5, wherein, The glue outlet of the glue gun (200) forms an angle with the to-be-glued area (101) and moves to glue at a preset speed, and after gluing the to-be-glued area (101) by using the glue gun (200), the method further comprises the following steps: scraping off the glue outside the to-be-glued area (101).

7. The solid-state battery processing method of claim 6, wherein, The angle is set to 10°-80°, and the preset speed is set to 40 mm / s-200 mm / s.

8. The solid-state battery processing method of claim 1, wherein, The outer diameter of the support is not greater than the outer diameter of the solid-state electrolyte layer (130).

9. The solid-state battery processing method of claim 1, wherein, The glue is set as a solid-state electrolyte slurry.

10. The solid-state battery processing method of any one of claims 1-9, wherein, After gluing the circumferential direction of the positive electrode sheet (120), the method further comprises the following steps: solidifying to form a single battery cell.

11. The solid-state battery processing method of claim 10, wherein, Stacking a plurality of single battery cells in sequence to form a battery cell unit, and pressing the battery cell unit at a preset pressure to form the solid-state battery.

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