CN115763681A - Method and equipment for supplementing lithium to negative pole piece - Google Patents
Method and equipment for supplementing lithium to negative pole piece Download PDFInfo
- Publication number
- CN115763681A CN115763681A CN202111038881.2A CN202111038881A CN115763681A CN 115763681 A CN115763681 A CN 115763681A CN 202111038881 A CN202111038881 A CN 202111038881A CN 115763681 A CN115763681 A CN 115763681A
- Authority
- CN
- China
- Prior art keywords
- lithium
- pole piece
- negative pole
- rolling
- pressing roller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 186
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 183
- 230000001502 supplementing effect Effects 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 34
- 239000011888 foil Substances 0.000 claims abstract description 85
- 238000005096 rolling process Methods 0.000 claims abstract description 62
- 238000003825 pressing Methods 0.000 claims abstract description 52
- 239000013589 supplement Substances 0.000 claims abstract description 30
- 230000006835 compression Effects 0.000 claims description 28
- 238000007906 compression Methods 0.000 claims description 28
- 238000004804 winding Methods 0.000 claims description 5
- 239000000047 product Substances 0.000 abstract description 10
- 238000002360 preparation method Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 4
- 229910001416 lithium ion Inorganic materials 0.000 description 4
- 239000011149 active material Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000006245 Carbon black Super-P Substances 0.000 description 2
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 150000004820 halides Chemical class 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- ZVLDJSZFKQJMKD-UHFFFAOYSA-N [Li].[Si] Chemical compound [Li].[Si] ZVLDJSZFKQJMKD-UHFFFAOYSA-N 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000011883 electrode binding agent Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000006138 lithiation reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000009469 supplementation Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses a method and equipment for supplementing lithium to a negative pole piece, and relates to the technical field of batteries. The method for supplementing lithium to the negative pole piece comprises the following steps: s1, respectively drawing a lithium foil and a negative pole piece to a rolling area through a first drawing device and a second drawing device; the rolling area is provided with rolling equipment, the rolling equipment comprises a first pressing roller close to the lithium foil and a second pressing roller close to the negative pole piece, and at least part of the surface of the first pressing roller is provided with a structure protruding or sinking towards the surface of the lithium foil to be compensated; s2, rolling the lithium foil and the negative pole piece through a gap between a first pressing roller and a second pressing roller, wherein the lithium foil is positioned between the first pressing roller and the negative pole piece; and S3, respectively rolling the lithium foil after lithium supplement and the negative pole piece after lithium supplement through a first rolling device and a second rolling device. The invention can ensure that the lithium foil and the battery pole piece are tightly combined and are not easy to separate, and the battery pole piece is not easy to extend and deform to scrap the pole piece, thereby improving the product percent of pass of lithium supplement of the lithium foil.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a method and equipment for supplementing lithium to a negative pole piece.
Background
Lithium foil lithium supplement is a battery cathode lithium supplement mode which is easy to realize mass production and high in safety, and the first effect, the battery capacity, the energy density and the cycle performance of the battery can be improved by lithium foil lithium supplement. The lithium foil is usually rolled together with the battery negative electrode by a roll press or a compound machine, so that the lithium metal is transferred from the lining film to the battery negative electrode.
In the prior art, the outer surface of a press roll of a rolling press or a compound machine used for lithium foil lithium supplement is generally smooth, and when the press roll is used for rolling, the problems exist: when the pressure applied on the compression roller is small, the metal lithium and the battery negative electrode are not tightly combined, and the metal lithium and the battery negative electrode are easy to separate; when the pressure applied on the compression roller is large, the battery negative electrode can be subjected to extension deformation, and the pole piece is scrapped. Therefore, the lithium foil lithium supplement final product yield by adopting the smooth pressing roller is lower.
On the other hand, although lithium supplement can improve the first efficiency of the battery, the lithium supplement is limited by the current lithium battery equipment, the thickness of the commercialized lithium supplement lithium foil is more than 5 μm, the surface density is high, the lithium supplement exceeds the actual lithium supplement requirement, so that excessive lithium ions are caused, lithium residues exist after the lithium supplement process is finished, and even lithium precipitation of the negative electrode is caused in severe cases.
In order to solve the problem, the current research direction mainly lies in the preparation of ultrathin lithium foil, but the requirement of the method on equipment is too high, and the complete industrialization is difficult at present.
Therefore, how to increase the product yield of lithium foil lithium supplement becomes a technical problem to be solved by those skilled in the art.
Disclosure of Invention
The invention provides a method for supplementing lithium to a negative pole piece, which can ensure that a lithium foil and a battery pole piece are tightly combined and are not easy to separate, and the pole piece is not easy to scrap due to the fact that the battery pole piece is deformed by extension, so that the product percent of pass of lithium supplement to the lithium foil can be improved.
The invention provides the following scheme:
a lithium supplementing method for a negative pole piece comprises the following steps:
s1, respectively drawing a lithium foil and a negative pole piece to a rolling area through a first drawing device and a second drawing device; the rolling area is provided with a rolling device, the rolling device comprises a first pressing roller close to the lithium foil and a second pressing roller close to the negative pole piece, and at least part of area of the surface of the first pressing roller is provided with a structure protruding or sinking towards the surface of the lithium foil to be compensated;
s2, rolling the lithium foil and the negative pole piece through a gap between the first compression roller and the second compression roller, wherein the lithium foil is positioned between the first compression roller and the negative pole piece;
and S3, respectively rolling the lithium foil after lithium supplement and the negative pole piece after lithium supplement through a first rolling device and a second rolling device.
And (3) calendering the lithium foil and the negative pole piece by utilizing a first compression roller and a second compression roller of the rolling equipment, wherein the surface of the first compression roller is provided with a convex or concave structure facing the surface to be compensated with lithium, so that part of the lithium foil and the negative pole piece is stressed during rolling, and the lithium foil is discontinuously adhered to the surface of the negative pole piece to finish lithium compensation.
Optionally, the raised structure comprises one of a textured structure or a striped structure.
Optionally, the area of the raised or recessed features comprises [20-80% of the roll face area of the first press roll ].
Optionally, the height of the raised structures is [2-1000 μm ].
Optionally, the recessed features have a depth of [2-1000 μm ].
Optionally, the first pressing roller comprises a first limiting belt, the second pressing roller comprises a second limiting belt, the first limiting belt and the second limiting belt are arranged oppositely,
optionally, the lithium supplementing method for the negative electrode sheet further includes:
and determining the sum of the thicknesses of the first limiting belt and the second limiting belt according to the sum of the thicknesses of the negative pole piece and the lithium foil.
Optionally, the determining the sum of the thicknesses of the first stopper band and the second stopper band according to the sum of the thicknesses of the pole piece and the lithium foil comprises:
setting the difference between the sum of the thicknesses of the first limit belt and the second limit belt and the sum of the thicknesses of the pole piece and the lithium foil to be larger than a first preset threshold value and smaller than a second preset threshold value.
A second aspect of the present invention provides a lithium supplementing apparatus for implementing the lithium supplementing method described in the first aspect, including:
the device comprises traction equipment, rolling equipment and winding equipment;
the traction equipment comprises a first traction equipment and a second traction equipment, the first traction equipment pulls the lithium foil to the rolling area, and the second traction equipment pulls the negative pole piece to the rolling area;
the rolling equipment comprises a first pressing roller and a second pressing roller, wherein at least partial area of the surface of the first pressing roller is provided with a convex or concave structure facing the second pressing roller.
Optionally, the first pressing roller comprises a first limiting belt, the second pressing roller comprises a second limiting belt, the first limiting belt and the second limiting belt are arranged oppositely, and the thickness of the first limiting belt and the thickness of the second limiting belt are determined according to the thickness sum of the pole piece and the lithium foil.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
at least part of the surface of the first pressing roller of the rolling device used in the lithium supplementing method is provided with a convex or concave structure facing the surface to be supplemented with lithium, and the convex or concave structure enables partial contact between the lithium foil and the negative pole piece in the rolling process, so that the lithium supplementing density can be adjusted, and excessive lithium ions cannot be caused. And partial contact between the lithium foil and the negative pole piece enables the lithium foil and the negative pole piece to be tightly combined under smaller applied pressure, the lithium foil and the negative pole piece are not easy to separate, and the battery pole piece is not easy to extend and deform to cause pole piece scrap. Therefore, the problems caused by the smooth surface compression roller in the prior art can be solved, and the product percent of pass is improved. In some preferred cases, the lithium supplementing method provided by the embodiment is adopted to increase the product yield from less than 50% to more than 95%.
Of course, embodiments of the invention need not achieve all of the above-described advantages at the same time.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly described below, 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 the drawings without creative efforts.
Fig. 1 is a block flow diagram of a method for supplementing lithium to a pole piece according to an 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 only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived from the embodiments of the present invention by a person skilled in the art, are within the scope of the present invention.
Fig. 1 is a block flow diagram of a method for supplementing lithium to a pole piece according to an embodiment of the present invention. The invention provides a method for supplementing lithium to a negative pole piece, which is used for supplementing lithium to a lithium battery and generally comprises the following steps:
s1, respectively drawing a lithium foil and a negative pole piece to a rolling area through first drawing equipment and second drawing equipment; the rolling area is provided with rolling equipment, the rolling equipment comprises a first pressing roller close to the lithium foil and a second pressing roller close to the negative pole piece, and at least part of the surface of the first pressing roller is provided with a structure protruding or sinking towards the surface of the lithium foil to be compensated;
s2, rolling the lithium foil and the negative pole piece through a gap between a first pressing roller and a second pressing roller, wherein the lithium foil is positioned between the first pressing roller and the negative pole piece;
and S3, respectively rolling the lithium foil after lithium supplement and the negative pole piece after lithium supplement through a first rolling device and a second rolling device.
Set up protruding or sunk structure through the first compression roller roll surface that is close to lithium paper tinsel one side for the effort that the compression roller was exerted on the lithium paper tinsel is partly acted on the lithium paper tinsel surface, and then makes the lithium paper tinsel partly with the contact of negative pole piece, and this makes the roll-in-process, under less applied pressure, can make lithium paper tinsel and negative pole piece combine closely, and both are difficult to break away from, and are difficult to make battery pole piece take place to extend and warp and cause the pole piece to scrap.
The proportion of depressions and/or projections can be adjusted according to the desired lithium supplementation, preferably the area of the projections or depressions represents [20-80% ] of the surface area of the first roll.
In one embodiment, the convex or concave structures are uniformly arranged, so that the lithium foil is non-continuously and uniformly adhered to the negative electrode sheet.
Preferably, the number of the convex or concave structures per inch of the length of the surface of the first press roll is [30-1000], and the number of the convex and/or concave structures is 30, 50, 80, 100, 300, 500, 600, 800 or 1000.
It should be noted that, in some embodiments, the negative electrode pole piece is wound on an unwinding roller, the unwinding roller is disposed upstream of the first traction device, and correspondingly, a winding roller for collecting the pole piece after lithium supplement is further disposed downstream of the rolling device. When lithium is supplemented, the unwinding roller, the rolling equipment and the winding roller work simultaneously.
In the rolling apparatus used in the lithium supplementing method provided in this embodiment, at least a partial region of the surface of the first roller is provided with a convex or concave structure facing the lithium surface to be supplemented, and during the rolling process, a convex portion (when the surface of the first roller is provided with a convex structure, the convex portion is formed by the convex structure, and when the surface of the first roller is provided with a concave structure, the convex portion is a portion other than the concave structure) contacts the lithium foil, so as to bond the lithium foil to the lithium surface to be supplemented. The contact area between the lithium foil and the first compression roller is reduced by the aid of the convex or concave structures, and under the condition that the pressure applied to the first compression roller is the same, the pressure acting on the lithium foil is larger, so that the lithium foil and the battery pole piece are tightly combined and are not easy to separate, and the battery pole piece is not easy to extend and deform to cause pole piece scrapping. Therefore, the problems caused by the smooth surface compression roller in the prior art can be solved, and the product percent of pass is improved. In some preferred cases, the lithium supplementing method provided by the embodiment is adopted to increase the product yield from less than 50% to more than 95%.
The shape of the concave and/or convex structures is not particularly limited, and any common shape can be used in the present application without departing from the inventive concept of the present application, including but not limited to one or more of circular, oval, linear, and curved.
In a preferred embodiment, the raised structure comprises one of a textured structure or a striped structure. The cross-hatched structure generally refers to a structure formed by lines extending in different directions crossing each other, and the striped structure generally refers to a structure formed by an arrangement of lines extending in substantially the same direction.
The height or the depth of the convex and/or concave structure is not particularly required, and the lithium foil can be ensured to be in contact with the negative pole piece part on the basis of not departing from the inventive concept of the application. The height and/or depth may have a value of 2-1000 μm, it being understood that when using a raised structure, the height represents the distance of the roll surface of the first pressure roll to the top surface of the raised structure, and when using a recessed structure, the depth represents the distance of the roll surface of the first pressure roll to the bottom surface of the recessed structure. The height or depth of the raised and/or recessed structures is 2 μm, 3 μm, 5 μm, 10 μm, 20 μm, 50 μm, 100 μm, 300 μm, 500 μm or 1000 μm.
The type of the lithium foil is not particularly limited in the present application, and it is understood that any known foil covered on the negative electrode tab and capable of supplementing lithium to the negative electrode through a specific lithium supplementing process can be used in the present application, including but not limited to elemental lithium, lithium silicon alloy, and the like.
The cathode can be applied to a liquid battery, a solid battery or a solid-liquid mixed battery, and the battery further comprises a positive pole piece, electrolyte and/or solid electrolyte.
Preferably, the negative active material comprises one or more of Si-based material, sn-based material, si/C, siO/C, sn/C, si halide, sn halide, si alloy and Sn alloy.
The positive electrode plate includes a positive electrode current collector and a positive electrode active material, and as an embodiment of the present application, there is no particular limitation on an application system, and any known positive electrode active material and positive electrode plate can be used in the present application on the basis of not violating the inventive concept of the present application.
The specific types of the separator, solid electrolyte, and electrolyte in the battery are not particularly limited, and may be any material used in existing batteries without departing from the inventive concept of the present application.
In a specific embodiment, the first pressing roller includes a first limiting belt, the second pressing roller includes a second limiting belt, the first limiting belt and the second limiting belt are arranged oppositely, and the method for supplementing lithium to the negative electrode plate further includes:
and determining the sum of the thicknesses of the first limit band and the second limit band according to the sum of the thicknesses of the negative pole piece and the lithium foil.
Preferably, the first limit belt and the second limit belt are both arranged at positions corresponding to the battery tabs of the pole pieces. The compression roller in the prior art is adopted for lithium supplement, so that metal lithium is adhered to the pole lug of the battery easily, and the subsequent welding of the pole lug is influenced. In order to solve the problem, the first limiting belt or the second limiting belt is arranged at the position, corresponding to the pole lug, of the compression roller, so that the pole lug is prevented from being adhered with metal lithium, and the problem in the prior art is solved.
More preferably, in some embodiments, only the first stop band may be provided, or only the second stop band may be provided. Specifically, the first limiting belt and the second limiting belt are arranged along the circumferential direction of the press roller.
In a specific embodiment, determining the sum of the thicknesses of the first position-limiting band and the second position-limiting band according to the sum of the thicknesses of the negative electrode pole piece and the lithium foil comprises:
setting the difference between the thickness sum of the first limiting belt and the second limiting belt and the thickness sum of the negative pole piece and the lithium foil to be larger than a first preset threshold value and smaller than a second preset threshold value.
The gap size between the first pressing roller and the second pressing roller is smaller than the sum of the thicknesses of the negative pole piece and the lithium foil, and the rolling equipment rolls the lithium foil and the negative pole piece in a corresponding state, so that the lithium foil is discontinuously adhered to the negative pole piece. And the remaining portion of the lithium foil except for the portion intermittently adhered to the negative electrode tab is intermittently remained on the lithium foil.
It is understood that other known lining films can be arranged between the first pressing roller, the lithium foil, the negative pole piece and the second pressing roller without departing from the inventive concept of the present application, and the meaning of the lining film is understood to be an auxiliary film which is not substantially used for supplementing lithium and is only arranged for the purpose of smoother rolling process. The present invention is not particularly limited in the kind of the backing film, and any known backing film can be used in the present application.
The negative electrode sheet includes a current collector and an active material layer, and it is understood that a lithium foil is disposed on one side of the active material layer, in contact with the active material layer. In the lithium replenishing step, electrons spontaneously move to the negative electrode due to the potential difference, and Li + is inserted into the negative electrode.
Specifically, assuming that the sum of the thicknesses of the lithium foil and the pole piece is H1, the thicknesses of the first limiting band and the second limiting band are H2 and H3, respectively, and a first preset threshold value < H2+ H3-H1< a second preset threshold value is set, wherein the first preset threshold value is-200 μm, and the second preset threshold value is 200 μm, so that the yield of the product can be further improved.
In a specific embodiment, before S1, the method for supplementing lithium to the negative electrode tab further includes:
and adjusting the gap between the first compression roller and the second compression roller to ensure that the lithium surface to be compensated is attached to the lithium foil, wherein the gap between the first compression roller and the second compression roller is slightly smaller than the sum of the thicknesses of the pole piece and the lithium foil, so that a certain pressure is formed between the lithium surface to be compensated and the lithium foil.
In a specific embodiment, the step of placing the lithium foil on the lithium surface to be compensated of the pole piece comprises the following steps:
the invention also provides equipment special for realizing the method for supplementing lithium to the negative pole piece in the embodiment, which comprises traction equipment, rolling equipment and winding equipment;
the traction equipment comprises a first traction equipment and a second traction equipment, the first traction equipment pulls the lithium foil to the rolling area, and the second traction equipment pulls the negative pole piece to the rolling area. The rolling device comprises a first pressing roller and a second pressing roller, wherein at least partial area of the surface of the first pressing roller is provided with a convex or concave structure facing the second pressing roller. The arrangement ratio of the concave and/or convex can be adjusted according to the required lithium supplement amount, and preferably, the area of the convex/concave structure accounts for [20-80% ] of the roll surface area of the first press roll.
The height or the depth of the convex and/or concave structure is not particularly required, and the lithium foil can be ensured to be in contact with the negative pole piece part on the basis of not departing from the inventive concept of the application. The height and/or depth may have a value of 2-1000 μm, it being understood that when a raised structure is used, the height represents the distance of the roll surface of the press roll to the top surface of the raised structure, and when a recessed structure is used, the depth represents the distance of the roll surface of the press roll to the bottom surface of the recess. The height or depth of the raised and/or recessed structures is 2 μm, 3 μm, 5 μm, 10 μm, 20 μm, 50 μm, 100 μm, 300 μm, 500 μm or 1000 μm. At least a partial area of the surface of the first pressing roll of the rolling device used in the lithium pole piece lithium supplementing device provided by this embodiment is provided with a convex structure facing the lithium surface to be supplemented, and in the rolling process, the convex structure is in contact with the lithium foil, so as to combine the lithium foil with the lithium surface to be supplemented. Therefore, the problems caused by the smooth surface compression roller in the prior art can be solved, and the product percent of pass is improved. In some preferred cases, the lithium supplementing method provided by the embodiment is adopted to increase the product yield from less than 50% to more than 95%.
In a specific embodiment, the first pressing roller comprises a first limiting belt, the second pressing roller comprises a second limiting belt, the first limiting belt and the second limiting belt are arranged oppositely, and the thickness sum of the first limiting belt and the second limiting belt is determined according to the thickness sum of the pole piece and the lithium foil. The lithium equipment is mended to pole piece that this embodiment provided can mend lithium to the two sides of pole piece simultaneously.
Preparation of the Battery
(1) Preparation of positive electrode
Mixing and dissolving LCO, super-P and PVDF in a solvent NMP according to a ratio of 96.
(2) Negative pole piece
Dissolving SiO/C (SiO material which is not subjected to pre-lithiation treatment), super-P and a negative electrode binder (SBR + CMC) in a solvent according to a ratio of 95.
(3) Negative electrode lithium supplement
Preparing a lithium foil with the thickness of 8 microns, and respectively drawing the lithium foil and a negative pole piece to a rolling area through a first drawing device and a second drawing device, wherein the rolling device comprises a first pressing roller and a second pressing roller, and the first pressing roller is provided with a convex structure with the height of 30 microns or a concave structure with the depth of 30 microns;
the lithium foil and the negative pole piece pass through a gap between the first compression roller and the second compression roller through the action of the first traction device and the second traction device to complete rolling, wherein the lithium foil is in contact with the first compression roller, the negative pole piece is in contact with the second compression roller, and the rolling pressure is 8T.
(4) Preparation of lithium ion battery
And (4) laminating the positive pole piece, the negative pole piece treated in the step (3) and the diaphragm, placing the laminated positive pole piece, the negative pole piece and the diaphragm into an aluminum-plastic film, and injecting liquid to form the lithium ion battery.
Preparation of comparative example cell: compared with the preparation method of the embodiment, the difference is that the first press roller and the second press roller are the same only in the step (3), and the rollers are both smooth rollers, and the rest are the same as the embodiment.
And (3) performance testing:
(1) Lithium replenishment interface observation
And (3) performing formation on the battery by using 1C charging and discharging current, removing the battery core after the formation is completed, observing the formation interface, wherein if metallic lithium residues exist on the interface, the lithium supplement amount is excessive, and if no metallic lithium residues exist, the lithium supplement amount is moderate.
(2) First charge-discharge efficiency
Charging was carried out at room temperature at 1/3C to the end voltage, the current was cut off at 0.05C, the charge capacity was recorded, and the mixture was allowed to stand for 30min. Discharging to the end voltage at 1/3C, recording the discharge capacity, and obtaining the first charge-discharge efficiency by using the discharge capacity to the charge capacity.
(3) 500 cycle efficiency
1. Charging at room temperature at 1C or specified current to stop voltage, stopping current at 0.05C, and standing for 30min;
2. discharging at 1C to discharge final voltage, recording discharge capacity, and standing for 30min;
circulating for 500 times (1) - (2);
3. the 500-cycle performance was calculated.
The test results are given in the following table:
by comparing examples 1-4 with comparative example 1, it can be shown that the lithium battery prepared by the lithium supplement method of the present application greatly improves the first charge-discharge efficiency of the battery, and also overcomes the problem of metal lithium residue caused by excessive lithium supplement.
The technical solutions provided by the present invention are described in detail above, and specific examples are applied in this document to explain the structure and the implementation of the present invention, and the descriptions of the above examples are only used to help understanding the method and the core ideas of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (10)
1. A method for supplementing lithium to a negative pole piece is characterized by comprising the following steps:
s1, respectively drawing a lithium foil and a negative pole piece to a rolling area through a first drawing device and a second drawing device; the rolling area is provided with a rolling device, the rolling device comprises a first pressing roller close to the lithium foil and a second pressing roller close to the negative pole piece, and at least part of the surface of the first pressing roller is provided with a structure protruding or sinking towards the surface of the lithium foil to be compensated;
s2, rolling the lithium foil and the negative pole piece through a gap between the first compression roller and the second compression roller, wherein the lithium foil is positioned between the first compression roller and the negative pole piece;
and S3, respectively rolling the lithium foil after lithium supplement and the negative pole piece after lithium supplement through a first rolling device and a second rolling device.
2. The method for supplementing lithium to the negative electrode sheet of claim 1, wherein the raised or recessed structure comprises one of a cross-hatched structure or a striped structure.
3. The negative pole piece lithium supplementing method of claim 2, wherein the area of the convex or concave structure accounts for [20-80% of the roll surface area of the first press roll ].
4. The method for supplementing lithium to the negative electrode plate of any one of claims 1 to 3, wherein the height of the raised structure is [2-1000 μm ].
5. The method for supplementing lithium to the negative electrode sheet of any one of claims 1 to 3, wherein the depth of the recessed structure is [2-1000 μm ].
6. The negative pole piece lithium supplementing method according to any one of claims 1 to 3, wherein the first pressing roller comprises a first limiting belt, the second pressing roller comprises a second limiting belt, and the first limiting belt and the second limiting belt are arranged oppositely.
7. The negative pole piece lithium supplementing method according to claim 6, further comprising:
and determining the sum of the thicknesses of the first limit band and the second limit band according to the sum of the thicknesses of the negative pole piece and the lithium foil.
8. The method for supplementing lithium to the negative pole piece according to claim 7, wherein the determining the sum of the thicknesses of the first position limiting belt and the second position limiting belt according to the sum of the thicknesses of the negative pole piece and the lithium foil comprises:
and setting the difference between the thickness sum of the first limit belt and the second limit belt and the thickness sum of the negative pole piece and the lithium foil to be larger than a first preset threshold value and smaller than a second preset threshold value.
9. The utility model provides a lithium equipment is mended to negative pole piece which characterized in that includes:
the device comprises traction equipment, rolling equipment and winding equipment;
the traction equipment comprises a first traction equipment and a second traction equipment, the first traction equipment pulls the lithium foil to the rolling area, and the second traction equipment pulls the negative pole piece to the rolling area;
the rolling equipment comprises a first pressing roller and a second pressing roller, wherein at least partial area of the surface of the first pressing roller is provided with a convex or concave structure facing the second pressing roller.
10. The negative pole piece lithium supplementing device of claim 9, wherein the first pressing roller comprises a first limiting belt, the second pressing roller comprises a second limiting belt, and the first limiting belt and the second limiting belt are arranged oppositely.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111038881.2A CN115763681A (en) | 2021-09-06 | 2021-09-06 | Method and equipment for supplementing lithium to negative pole piece |
| PCT/CN2022/081325 WO2023029437A1 (en) | 2021-09-06 | 2022-03-17 | Lithium replenishment method for negative electrode plate, and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111038881.2A CN115763681A (en) | 2021-09-06 | 2021-09-06 | Method and equipment for supplementing lithium to negative pole piece |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115763681A true CN115763681A (en) | 2023-03-07 |
Family
ID=85332751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111038881.2A Pending CN115763681A (en) | 2021-09-06 | 2021-09-06 | Method and equipment for supplementing lithium to negative pole piece |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115763681A (en) |
| WO (1) | WO2023029437A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116773607A (en) * | 2023-08-24 | 2023-09-19 | 宁德时代新能源科技股份有限公司 | Method and equipment for detecting lithium supplementing quantity |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116960266A (en) * | 2023-09-21 | 2023-10-27 | 河南锂动电源有限公司 | Pole piece lithium supplementing device, pole piece lithium supplementing system and pole piece lithium supplementing method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5493656B2 (en) * | 2009-09-30 | 2014-05-14 | 日本ゼオン株式会社 | Electrode device electrode manufacturing method and manufacturing apparatus |
| CN207038628U (en) * | 2017-07-12 | 2018-02-23 | 宁德时代新能源科技股份有限公司 | Pole piece mends lithium device |
| CN206878097U (en) * | 2017-07-12 | 2018-01-12 | 宁德时代新能源科技股份有限公司 | Pole piece mends lithium device |
| CN107819104B (en) * | 2017-09-27 | 2020-06-26 | 天津力神电池股份有限公司 | Preparation method of lithium-copper composite negative electrode foil |
| CN208127310U (en) * | 2018-04-10 | 2018-11-20 | 宁德时代新能源科技股份有限公司 | Pole piece mends lithium device |
| CN112736216B (en) * | 2021-01-13 | 2024-10-15 | 深圳市镭煜科技有限公司 | Lithium belt calendaring and shearing mechanism |
| CN114030929A (en) * | 2022-01-10 | 2022-02-11 | 天津中能锂业有限公司 | Pole piece strip-shaped interval pre-lithiation device |
-
2021
- 2021-09-06 CN CN202111038881.2A patent/CN115763681A/en active Pending
-
2022
- 2022-03-17 WO PCT/CN2022/081325 patent/WO2023029437A1/en active Application Filing
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116773607A (en) * | 2023-08-24 | 2023-09-19 | 宁德时代新能源科技股份有限公司 | Method and equipment for detecting lithium supplementing quantity |
| CN116773607B (en) * | 2023-08-24 | 2024-04-12 | 宁德时代新能源科技股份有限公司 | Method and equipment for detecting lithium supplementing quantity |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023029437A1 (en) | 2023-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112397682B (en) | Negative pole piece for lithium supplement and lithium ion battery thereof | |
| CN111540880B (en) | Negative plate, preparation method and lithium ion battery comprising negative plate | |
| CN115763681A (en) | Method and equipment for supplementing lithium to negative pole piece | |
| CN110098377B (en) | Lithium ion battery with high capacity retention rate, preparation method and charge-discharge mode thereof | |
| CN113839084A (en) | Battery core and battery | |
| CN114695968B (en) | Lithium ion battery with NP ratio less than 1 and preparation method thereof | |
| CN109718999B (en) | Preparation method of lithium ion battery pole piece and preparation method of lithium ion battery | |
| CN113871572B (en) | Positive plate and lithium ion battery | |
| EP3923384B1 (en) | Device and method for replenishing lithium on pole piece | |
| CN112713258A (en) | Lithium ion battery | |
| CN113871571B (en) | Negative plate, battery cell and battery | |
| AU2019442510A1 (en) | Charging and discharging method for high-capacity retention rate lithium ion battery | |
| CN214956957U (en) | Battery with a battery cell | |
| CN113140697B (en) | Positive plate, lithium ion battery and preparation method of positive plate | |
| CN111540909A (en) | Pole piece, battery core and battery | |
| CN110676518A (en) | Method for preventing lithium precipitation of lithium ion battery cathode | |
| CN113421996A (en) | Negative plate, battery and manufacturing method of negative plate | |
| CN210628412U (en) | Manufacturing equipment for alkali metal composite cathode | |
| CN216015424U (en) | Pole piece and battery comprising same | |
| CN113889597B (en) | Pole piece and lithium ion battery | |
| CN114361563A (en) | Battery cell structure and battery | |
| CN112993208B (en) | Lithium ion energy storage device, pre-lithiation method thereof and preparation method thereof | |
| CN220382154U (en) | Secondary battery and electronic device | |
| CN111786010A (en) | Multiplying power type lithium ion battery | |
| CN112397684A (en) | Multi-tab battery pole piece and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |