CN220456477U

CN220456477U - Composite pole piece, preparation device thereof and lithium ion battery

Info

Publication number: CN220456477U
Application number: CN202321843129.XU
Authority: CN
Inventors: 施展; 冯玉川; 李峥
Original assignee: Suzhou Qingtao New Energy S&T Co Ltd
Current assignee: Suzhou Qingtao New Energy S&T Co Ltd
Priority date: 2023-07-13
Filing date: 2023-07-13
Publication date: 2024-02-06
Anticipated expiration: 2033-07-13

Abstract

The application provides a composite pole piece, a preparation device thereof and a lithium ion battery. The device comprises a shaping roller assembly, a shaping roller assembly and a shaping roller assembly, wherein the shaping roller assembly is used for carrying out rolling compounding on an electrode plate, a solid electrolyte membrane and a protective film to form a composite electrode plate; the electrode pole piece unreeling mechanism is used for conveying the electrode pole piece to pass through a gap between the first shaping roller and the second shaping roller; the solid electrolyte membrane unreeling mechanism is used for conveying the solid electrolyte membrane to pass through a gap between the electrode pole piece and the shaping roller assembly; the protective film unreeling mechanism is used for conveying the protective film to pass through a gap between the solid electrolyte film and the shaping roller assembly; the heating mechanism is used for preheating the electrode pole piece, the solid electrolyte membrane and the protective film; the cooling roller is positioned at the downstream of the shaping roller assembly and is used for cooling the composite pole piece. The preparation device in the application improves the degree of compounding among the electrode pole pieces, the solid electrolyte membrane and the protective film, and improves the consistency of the transverse thickness of the compound pole pieces.

Description

Composite pole piece, preparation device thereof and lithium ion battery

Technical Field

The application relates to the technical field of lithium ion batteries, in particular to a composite pole piece, a preparation device thereof and a lithium ion battery.

Background

With the continuous emergence of new technology in the field of batteries, lithium ion batteries become a main stream energy storage device in the current market due to the excellent battery performance, electrode plates are important components of lithium ion batteries, a wet process is usually adopted to coat a solid electrolyte material layer on the surface of the electrode plates for improving the safety performance of the batteries, but the volatilization of solvents in the coated solid electrolyte layer easily causes shrinkage deformation of the electrode plates, and the battery performance is affected. Therefore, research and development people gradually aim at the composite pole piece of the electrode pole piece and the solid electrolyte membrane prepared by the dry process to improve the safety performance of the battery, however, in the rolling step of preparing the composite pole piece by the dry process, the roll is easy to generate deflection deformation due to the limitations of rigidity of roll press equipment and deformation resistance of rolls, the phenomena of thick middle and thin two ends of the rolled positive pole/negative pole piece can be caused, and further, when the positive pole/negative pole piece and the solid electrolyte membrane are subjected to rolling lamination, the problems of poor lamination effect, inconsistent transverse compaction density and poor transverse thickness consistency of the composite pole piece are easily caused, and the safety performance and quality of the lithium ion battery can be greatly influenced.

Disclosure of Invention

Based on this, the first aspect of the present application provides a preparation device of a composite pole piece, the device includes:

the shaping roller assembly comprises a first shaping roller and a second shaping roller and is used for carrying out rolling compounding on the electrode pole piece, the solid electrolyte membrane and the protective film to form a compound pole piece;

the electrode pole piece unreeling mechanism is positioned at the upstream of the shaping roller assembly and is used for conveying the electrode pole piece so that the electrode pole piece passes through a gap between the first shaping roller and the second shaping roller;

the solid electrolyte membrane unreeling mechanism is positioned at the side edge of the electrode pole piece unreeling mechanism and is used for conveying the solid electrolyte membrane so that the solid electrolyte membrane passes through a gap between the electrode pole piece and the shaping roller assembly;

the protective film unreeling mechanism is positioned between the solid electrolyte film unreeling mechanism and the shaping roller assembly and is used for conveying the protective film so that the protective film passes through a gap between the solid electrolyte film and the shaping roller assembly;

the heating mechanism is positioned between the electrode pole piece unreeling mechanism and the shaping roller assembly and is used for preheating the electrode pole piece, the solid electrolyte membrane and the protective film; and

and the cooling roller is positioned at the downstream of the shaping roller assembly and is used for cooling the composite pole piece.

In some embodiments, the apparatus for preparing a composite pole piece further comprises a composite pole piece winding mechanism positioned downstream of the sizing roller assembly for receiving the composite pole piece.

In some embodiments, the apparatus for preparing a composite pole piece further comprises a substrate winding mechanism, located between the shaping roller assembly and the composite pole piece winding mechanism, for receiving a substrate covered on the solid electrolyte membrane;

the substrate winding mechanism and the solid electrolyte membrane unwinding mechanism are positioned on the same side of the electrode pole piece unwinding mechanism.

In some embodiments, the apparatus for manufacturing a composite pole piece further comprises a protective film winding mechanism positioned between the shaping roller assembly and the substrate winding mechanism for receiving the protective film.

In some embodiments, the protective film is a polymeric film or a nonwoven.

In some embodiments, the heating mechanism preheats the electrode sheet, the solid electrolyte membrane and the protective film for a period of greater than or equal to 2S.

In some embodiments, the number of the heating mechanisms is a plurality of, and the heating mechanisms are used for simultaneously preheating the electrode pole piece, the solid electrolyte membrane and the protective film for a plurality of times, and the preheating temperature is gradually increased.

In some embodiments, the number of the solid electrolyte membrane unreeling mechanisms is two, and the solid electrolyte membrane unreeling mechanisms are symmetrically arranged at two sides of the electrode pole piece unreeling mechanism.

The second aspect of the application provides a composite pole piece, which is prepared by the preparation device of the composite pole piece provided by the first aspect.

A third aspect of the present application provides a lithium ion battery comprising the composite pole piece provided in the second aspect.

The utility model provides a be provided with heating mechanism in the preparation facilities of compound pole piece, preheat electrode pole piece, solid electrolyte membrane and protection film simultaneously through heating mechanism, improved the holistic compliance of electrode pole piece, solid electrolyte membrane and protection film for three's ductility obtains improving simultaneously, and plasticity is better, thereby when shaping roller assembly carries out roll-in complex in-process to electrode pole piece, solid electrolyte membrane and protection film is whole, the interlock is inseparabler between adjacent membrane and the membrane, improved the adhesive strength between membrane and the membrane, improved the compound degree between electrode pole piece, solid electrolyte membrane and the protection film two by two.

According to the preparation device of the composite electrode plate, the protective film is attached to the two sides of the electrode plate and the solid electrolyte membrane before the rolling composite process, so that the protective effect is achieved, and in the rolling composite process, the stress conditions of the electrode plate and the solid electrolyte membrane in the rolling process are regulated through the buffer provided by the protective film, so that the solid electrolyte membrane can better cover the electrode plate; and the stress of the electrode pole piece and the solid electrolyte membrane in the rolling process is uniform, the transverse thickness of the electrode pole piece tends to be consistent after rolling, the adverse effect on the rolling compounding process caused by the phenomena of thick middle and thin two ends of the electrode pole piece is avoided, the electrode pole piece is prevented from being crushed, the compounding degree among the electrode pole piece, the solid electrolyte membrane and the protective film is improved, and the consistency of the transverse thickness of the compound pole piece is improved.

The cooling roller is arranged in the preparation device of the composite pole piece, so that the temperature of the composite pole piece coming out of a gap of the shaping roller assembly can be rapidly reduced, the composite pole piece can be continuously wound, and the production efficiency is improved; meanwhile, the cooling roller also provides shaping treatment for the composite pole piece.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a device for manufacturing a composite pole piece according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a device for manufacturing a second composite pole piece according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a device for preparing a three-composite pole piece according to an embodiment of the present application.

Description of the reference numerals

11. An electrode pole piece unreeling mechanism; 12. a composite pole piece winding mechanism;

21. a solid electrolyte membrane unreeling mechanism; 22. a substrate winding mechanism;

31. A first forming roller; 32. a second shaping roller;

41. a protective film unreeling mechanism; 42. a protective film winding mechanism,

51. a first guide roller; 52. a second guide roller; 53. a third guide roller; 54. a fourth guide roller; 55. a fifth guide roller; 56. a sixth guide roller; 57. a seventh guide roller; 58. an eighth guide roller; 59. a ninth guide roller;

71. a first heating roller; 72. a second heating roller; 73. a third heating roller; 74. and (5) cooling the roller.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that these terms "first," "second," "third," if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature.

In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

When a range of values is disclosed herein, the range is considered to be continuous and includes both the minimum and maximum values for the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values of the range is included. Further, when multiple range description features or characteristics are provided, the ranges may be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to include any and all subranges subsumed therein.

The terms "comprising," "including," "containing," "having," or other variations thereof herein are intended to cover a non-closed inclusion, without distinguishing between these terms. The term "comprising" means that other steps and components may be added that do not affect the end result. The compositions and methods/processes of the present application comprise, consist of, and consist essentially of the essential elements and limitations described herein, as well as additional or optional ingredients, components, steps, or limitations of any of the embodiments described herein.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

Referring to fig. 1-3, the preparation device of the composite pole piece comprises a shaping roller assembly, an electrode pole piece unreeling mechanism 11, a solid electrolyte membrane unreeling mechanism 21, a protective film unreeling mechanism 41, a heating mechanism and a composite pole piece reeling mechanism 12. The shaping roller assembly comprises a first shaping roller 31 and a second shaping roller 32 which are symmetrically arranged on two sides of the electrode pole piece; the connecting line between the axes of the first shaping roller 31 and the second shaping roller 32 is perpendicular to the conveying direction of the electrode sheet.

The electrode sheet unreeling mechanism 11 is located upstream of the shaping roller assembly for unreeling the electrode sheet, and then transporting the electrode sheet so that the electrode sheet passes through a gap between the first shaping roller 31 and the second shaping roller 32.

It is understood that the electrode sheet of the present application is a positive electrode sheet or a negative electrode sheet.

The solid electrolyte membrane unwind mechanism 21 is located upstream of the shaping roller assembly, and more specifically, between the electrode sheet unwind mechanism 11 and the shaping roller assembly. The solid electrolyte film unreeling mechanism 21 is used for unreeling the solid electrolyte film and then conveying the solid electrolyte film so that the solid electrolyte film passes through the gap between the first shaping roller 31 and the second shaping roller 32, and more specifically the solid electrolyte film unreeling mechanism 21 so that the solid electrolyte film passes through the gap between the electrode sheet and the shaping roller assembly.

In some embodiments, the number of the solid electrolyte membrane unreeling mechanisms 21 is two, which are respectively located at both sides of the electrode sheet unreeling mechanism 11, and then the solid electrolyte membrane is transported such that the two layers of the solid electrolyte membrane pass through the gap between the first shaping roller 31 and the second shaping roller 32, respectively, and the electrode sheet is located in the middle of the two layers of the solid electrolyte membrane.

Alternatively, two solid electrolyte membrane unreeling mechanisms 21 are symmetrically arranged on both sides of the electrode sheet unreeling mechanism 11.

The protective film unreeling mechanism 41 is located upstream of the shaping roller assembly, is disposed between the solid electrolyte film unreeling mechanism 21 and the shaping roller assembly, and is used for unreeling the protective film and conveying the protective film so that the protective film passes through a gap between the solid electrolyte film and the shaping roller assembly. More specifically, the protective film is transported through the gap between the sizing roller assembly and the solid electrolyte membrane.

The present application has no particular requirement on the structure of the protective film, and it is known that a film layer capable of being elastically deformed to a certain extent under a certain pressure can be used in the present application without departing from the inventive concept of the present application. By way of illustrative example only, and not limitation of the scope of protection, the protective film may be selected from polymeric films or nonwoven fabrics including, but not limited to, PP-based nonwoven fabrics, PE-based nonwoven fabrics, PET-based nonwoven fabrics, PAN-based nonwoven fabrics, PTFE-based nonwoven fabrics, celgard nonwoven fabrics, and the like; the polymer film may be selected from PVDF film, PE film, PP film, PE/PP/PE film, PP/PE/PP film, PTFE film, silicone oil release film, fluorine release film, PET film, non-silicon release film, etc. It is understood that the protective film may also be a multilayer structure consisting of two or more layers of polymer film and/or nonwoven fabric.

The thickness of the protective film is not particularly limited, and conventional adjustment of the thickness of the protective film for adjusting the rolling effect is considered to be within the scope of the present application without departing from the inventive concept of the present application, and it is understood that when the protective film is a multilayer structure, the thickness of the protective film should be the sum of the thicknesses of the multilayer structure.

The heating mechanism is positioned between the electrode pole piece unreeling mechanism 11 and the shaping roller assembly and is used for preheating the electrode pole piece and/or the solid electrolyte membrane and/or the protective film.

In some embodiments, the heating mechanism is a heated roller.

In some embodiments, the number of heating rollers in the composite pole piece manufacturing device is not particularly limited, and the specific number of heating rollers may be increased or decreased according to actual situations.

In some embodiments, the number of heating rollers may be one, i.e., the first heating roller 71.

In some embodiments, the number of the heating rollers can be multiple, and the temperature of the heating rollers gradually rises along the running direction of the electrode pole pieces, so that the preheating effect is more uniform. Specifically, the heating rollers are a first heating roller 71, a second heating roller 72, and a third heating roller 73 in the running direction of the electrode sheet, wherein the number of the first heating roller 71, the second heating roller 72, and the third heating roller 73 may be 1, 2, or more, respectively, and the number is not particularly limited herein.

In some embodiments, the heated roller is preheated for a period of greater than or equal to 2S.

In some embodiments, heated rollers are used to preheat the electrode sheet, solid electrolyte membrane, and protective film simultaneously.

The composite pole piece winding mechanism 12 is located at the downstream of the shaping roller assembly and is used for providing a pulling force along the movement direction of the electrode pole piece for the electrode pole piece, receiving the composite pole piece obtained after the rolling and compounding by the shaping roller assembly and completing the winding action.

It is understood that the preheating mode is not particularly limited in the present application, and the electrode sheet, the solid electrolyte membrane and the protective film may be preheated by contact type preheating, blast type preheating, radiation type preheating or the like. Preferably, the S-shaped double-roller contact type heating is adopted, and space can be saved through a roller with a large wrap angle or a plurality of heating rollers with smaller volumes. Under lower cost, the preheating device realizes rapid heating, has short preheating stroke and high heat transfer speed, and can realize independent temperature control of any heating roller in contact type preheating.

In some embodiments, the apparatus for producing a composite pole piece further includes a protective film winding mechanism 42, the protective film winding mechanism 42 being located downstream of the shaping roller assembly, between the shaping roller assembly and the composite pole piece winding mechanism 12, for providing tension to the protective film and winding up and receiving the protective film.

In some embodiments, the apparatus for preparing a composite pole piece further includes a substrate take-up mechanism 22.

When the base material is arranged on the solid electrolyte membrane, the base material covers one side of the solid electrolyte membrane far away from the electrode plate, and the base material is required to be separated after the electrode plate and the solid electrolyte membrane are rolled by the shaping roller assembly to obtain the composite electrode plate. The separation of the substrate from the composite pole piece is accomplished by providing a substrate take-up mechanism 22 downstream of the sizing roller assembly. In the separation process, the substrate winding mechanism 22 provides a pulling force to the substrate covered on the solid electrolyte membrane, so that the substrate is separated from the composite pole piece, and the substrate winding action is completed if necessary.

The number of the substrate winding mechanisms 22 corresponds to the number of the solid electrolyte membrane unwinding mechanisms 21, and the substrate winding mechanisms 22 and the solid electrolyte membrane unwinding mechanisms 21 are located on the same side of the electrode sheet unwinding mechanism 11.

The type of the base material is not particularly limited, and any known material which has a certain supporting effect, can be more beneficial to film formation of electrolyte materials and can be separated from a solid electrolyte membrane after rolling can be used in the application on the basis of not departing from the inventive concept of the application; by way of illustrative example only, and not by way of any limitation of the scope of protection, the substrate is selected from one or more of silicone oil release film, fluorine release film, PET film, PP film, PE/PP film, PP/PE/PP film, PE/PP/PE film, non-silicon release film.

In some embodiments, the apparatus for preparing a composite pole piece further comprises a guide roller.

Optionally, a guiding roller is located between the electrode sheet unreeling mechanism 11 and the shaping roller assembly for providing guiding action for the electrode sheet. A guide roller for providing guiding function to the composite pole piece winding can also be arranged between the shaping roller assembly and the composite pole piece winding mechanism 12.

Alternatively, a guide roller is located between the solid electrolyte membrane unwind mechanism 21 and the shaping roller assembly for providing a guide for the solid electrolyte membrane. A guide roller for guiding the substrate coated on the solid electrolyte membrane separated from the composite pole piece may also be provided between the shaping roller assembly and the substrate winding mechanism 22.

Optionally, a guide roller is located between the protective film unreeling mechanism 41 and the shaping roller assembly for providing a guiding action for the protective film. A guide roller for providing a guide function for the recovery of the protective film may also be provided between the setting roller assembly and the protective film take-up mechanism 42.

In some embodiments, the apparatus for preparing a composite pole piece further includes a chill roll 74 positioned between the sizing roll assembly and the composite pole piece take-up mechanism 12 for cooling the composite pole piece exiting the gap of the sizing roll assembly. The cooling roller 74 is arranged for reducing the temperature of the composite pole piece, so that the composite pole piece can be continuously wound, and the production efficiency is improved; at the same time, chill roll 74 also provides a sizing treatment for the composite pole piece.

In some embodiments, the number of chill rolls 74 may be 1 or more, preferably 2.

In some embodiments, a guide roller is disposed between the sizing roller assembly and the chill roller 74, and/or a guide roller is disposed between the chill roller 74 and the composite pole piece take-up mechanism 12 for adjusting the cooling time of the composite pole piece.

In some embodiments, the number of cooling rollers 74 and guide rollers in the composite pole piece manufacturing apparatus is not particularly limited, and the specific number may be increased or decreased according to the actual situation.

In some embodiments, the composite pole piece preparation device further comprises an unreeling deviation rectifying component, a pole piece static eliminating component and the like which are sequentially arranged along the unreeling route. The unreeling deviation correcting component can correct unreeling and running routes of the electrode pole pieces, the solid electrolyte membrane and the like, so that the starting material line is kept at the same level. The winding and unwinding mechanism of the main material adopts a single-station deviation correction, and the winding and unwinding of the rest materials adopts cantilever type with deviation correction. The static eliminating assembly performs static eliminating treatment on the two sides of the electrode pole piece, so that friction force between the pole piece and the conveying roller can be reduced. It is understood that known functional components or structures may be used in the present application throughout the process of winding, rolling, unwinding without departing from the inventive concepts of the present application.

In some embodiments, the composite pole piece manufacturing apparatus further comprises a tension control device.

In some embodiments, the tension control device includes a plurality of tension control elements disposed upstream of the sizing roller assembly for controlling the unreeling tension of the electrode sheet, the solid electrolyte membrane, and the protective film, respectively.

In some embodiments, the tension control device includes a plurality of tension control elements disposed downstream of the sizing roller assembly for controlling the winding tension of the composite pole piece, the substrate, and the protective film, respectively.

In some embodiments, the composite pole piece preparation device further comprises a thickness measuring mechanism, and after the shaping roller assembly is used for rolling and compounding, the composite pole piece enters the composite pole piece rolling mechanism 12 for rolling after passing through the inspection of the thickness measuring mechanism.

In some embodiments, the heated and cooled rollers 74 described above also include sensors for detecting the surface temperature of the composite pole piece.

In some embodiments, the sizing roller assembly has a width of 500-800mm, including but not limited to 500mm, 550mm, 600mm, 650mm, 700mm, 750mm, 800mm. Preferably 550-650mm.

In some embodiments, the sizing roller assembly has a roller diameter of 300-500mm, including but not limited to 300mm, 350mm, 400mm, 450mm, 500mm. Preferably 350-450mm.

In some embodiments, the tonnage of the sizing roll assembly is 10-15 tons, including but not limited to 11 tons, 12 tons, 13 tons, 14 tons, 15 tons. Preferably 11-13 tons.

In some embodiments, the mechanical speed of the sizing roller assembly is 10-30m/min, including but not limited to 10m/min, 15m/min, 20m/min, 25m/min.

It can be understood that the higher the tape running speed of the whole composite pole piece preparation device is, the higher the production efficiency is, but the higher the tape running speed is, the problems of tape breakage and the like of the tape running pole piece and the solid electrolyte membrane are easily caused. The residence time of the electrode pole piece and the solid electrolyte membrane in the gap of the shaping roller assembly is not particularly required, and the adjustment of the residence time without creative labor on the basis of not deviating from the inventive concept of the application is understood to fall within the protection scope of the application.

In some embodiments, the linear speeds of the first shaping roller 31 and the second shaping roller 32 are kept consistent, the linear speed of unreeling of the electrode pole piece unreeling mechanism 11 and the linear speed of reeling of the composite pole piece reeling mechanism 12 are also kept consistent, the action consistency of the whole composite pole piece rolling preparation process is improved, and the consistency of the composite pole piece is improved.

Referring to fig. 1 to 3, in combination with the structure of the preparation device of the composite pole piece, the preparation process of the composite pole piece of the application specifically comprises the following steps: unreeling the electrode sheet by the electrode sheet unreeling mechanism 11 and conveying the electrode sheet to the composite sheet reeling mechanism 12, so that the electrode sheet sequentially passes through a gap among the heating roller, the first shaping roller 31 and the second shaping roller 32; conveying the solid electrolyte membrane through a solid electrolyte membrane unreeling mechanism 21 positioned at the side edge of the electrode pole piece unreeling mechanism 11, so that the solid electrolyte membrane sequentially passes through a gap between the heating roller and the electrode pole piece, a gap between the shaping roller assembly and the electrode pole piece; unreeling the protective film by a protective film unreeling mechanism 41 positioned between the solid electrolyte film unreeling mechanism 21 and the shaping roller assembly, so that the protective film sequentially passes through a gap between the heating roller and the solid electrolyte film and a gap between the shaping roller assembly and the solid electrolyte film; laminating and preheating the electrode pole piece, the solid electrolyte membrane and the protective film at the heating roller before rolling, and then rolling and compounding the electrode pole piece, the solid electrolyte membrane and the protective film through the first shaping roller 31 and the second shaping roller 32 to prepare a composite membrane; finally, separating the protective film from the composite film sheet by a protective film winding mechanism 42 at the downstream of the shaping roller assembly to obtain a composite pole piece; the composite pole piece is cooled by the cooling roller 74 and then received by the composite pole piece winding mechanism 12.

In some embodiments, the composite electrode sheet comprises an electrode sheet and solid electrolyte membranes respectively positioned at two sides of the electrode sheet. At this time, after the electrode sheet is transported, the solid electrolyte film is unreeled by two solid electrolyte film unreeling mechanisms 21 respectively positioned at two sides of the electrode sheet unreeling mechanism 11 and is conveyed to the shaping roller assembly, so that the two layers of solid electrolyte films respectively pass through gaps among the heating roller, the first shaping roller 31 and the second shaping roller 32 in sequence; unreeling the protective film by two protective film unreeling mechanisms 41 positioned on one side of the solid electrolyte film unreeling mechanism 21 far away from the electrode pole piece, and conveying the protective film to the shaping roller assembly by the protective film unreeling mechanism 41 so that the two layers of protective film respectively pass through gaps among the heating roller, the first shaping roller 31 and the second shaping roller 32 in sequence; the protective film, the solid electrolyte film, the electrode pole piece, the solid electrolyte film and the protective film which are distributed in sequence are adhered to each other and preheated at the heating roller, and the solid electrolyte film is compounded on two sides of the electrode pole piece under the rolling action of the shaping roller assembly; thereby obtaining the composite pole piece.

In some embodiments, the solid electrolyte membrane is formed separately, i.e., the solid electrolyte membrane is formed without the aid of a substrate and the membrane remains intact. At this time, after the electrode pole piece, the solid electrolyte membrane and the protective film enter a gap of the shaping roller assembly, the composite pole piece is obtained under the pressure action of the shaping roller assembly, and the composite pole piece is wound by the electrode pole piece winding mechanism.

In some embodiments, the solid electrolyte membrane is covered with a substrate to provide support to the solid electrolyte membrane. The solid electrolyte membrane unreeling mechanism 21 makes the base material be located at the side of the solid electrolyte membrane far from the electrode plate when the solid electrolyte membrane is transported. And separating the base material from the composite electrode plate after the solid electrolyte membrane and the electrode plate are compounded. Specifically, the substrate can be received by the substrate winding mechanisms 22 respectively positioned at two sides of the composite pole piece winding mechanism 12, and the substrate winding mechanism 22 is positioned between the shaping roller assembly and the composite pole piece winding mechanism 12.

Alternatively, as shown in fig. 1 to 3, in the setting roller assembly and upstream thereof, the electrode sheet on the electrode sheet unreeling mechanism 11 reaches the first heating roller 71 after being guided by the first guide roller 51; the solid electrolyte membrane positioned on the upper side of the electrode sheet unreeling mechanism 11 reaches the first heating roller 71 after being guided by the first guide roller 51; the solid electrolyte membrane positioned at the lower side of the electrode pole piece unreeling mechanism 11 reaches the first heating roller 71 after being guided by the second guide roller 52 and the first guide roller 51; the protective film on the upper side of the electrode sheet unreeling mechanism 11 reaches the first heating roller 71 after being guided by the third guide roller 53; the protective film positioned at the lower side of the electrode pole piece unreeling mechanism 11 reaches the first heating roller 71 after being guided by the third guide roller 53, the second guide roller 52 and the first guide roller 51; the second guide roller 52 is positioned on the side of the first guide roller 51 away from the shaping roller assembly; the first guide roller 51 is located on the side of the third guide roller 53 remote from the setting roller assembly. The protective film, the solid electrolyte film, the electrode pole piece, the solid electrolyte film and the protective film are firstly attached and preheated at the first heating roller 71, then are preheated together through the second heating roller 72 and the third heating roller 73, are guided by the fourth guiding roller 54 and reach the shaping roller assembly, and are pressed by the rollers of the first shaping roller 31 and the second shaping roller 32 through the gap between the first shaping roller 31 and the second shaping roller 32, so that the composite film is obtained.

The electrode pole piece, the solid electrolyte membrane and the protective film are bonded and preheated simultaneously before rolling and compounding to obtain a bonding piece, the preheating temperature is increased, the overall flexibility of the bonding piece is improved, the effect of tight compounding is more easily achieved in the subsequent rolling and compounding process, and the compounding degree among the electrode pole piece, the solid electrolyte membrane and the protective film is improved. The 'simultaneous preheating' ensures that the whole laminating piece is heated to a consistent temperature, is heated uniformly and has higher laminating degree.

The shaping roller assembly applies tension to the electrode pole piece and the solid electrolyte membrane during rolling and compounding, and at the moment, the two layers of protective films are respectively positioned between the shaping roller assembly and the two layers of solid electrolyte membrane to play a role of buffering, so that the forces received by each site of the electrode pole piece and the solid electrolyte membrane are relatively uniform, the solid electrolyte membrane in the composite pole piece almost completely covers the electrode pole piece, the combination between the electrode pole piece and the solid electrolyte membrane is better, the consistency of the transverse thickness of the composite pole piece is improved, and the compaction density is also improved.

In some embodiments, the protective film and the substrate may be separated from the composite membrane simultaneously.

Alternatively, downstream of the sizing roller assembly, as shown in FIG. 1, the protective film is attached to and detached from the substrate. Specifically, the protective film and the substrate are guided by the fifth guide roller 55 and then respectively reach the protective film winding mechanism 42 and the substrate winding mechanism 22, and the protective film and the substrate are separated from the composite film to obtain a composite pole piece; the composite pole piece reaches the cooling roller 74 after being guided by the sixth guide roller 56, and reaches the composite pole piece winding mechanism 12 after being guided by the seventh guide roller 57, so as to finish winding the composite pole piece.

Alternatively, downstream of the sizing roller assembly, the protective film and the substrate may be passed through different guide rollers to the protective film take-up mechanism 42 and the substrate take-up mechanism 22, respectively, as shown in FIG. 2, without controlling the angular separation of the substrate and the composite film sheet. Specifically, the protective film reaches the protective film winding mechanism 42 after being guided by the fifth guide roller 55; the substrate reaches the substrate winding mechanism 22 after being guided by the ninth guide roller 59 and the eighth guide roller 58, and the line between the ninth guide roller 59 and the eighth guide roller 58 is a straight line; the protective film and the substrate are separated from the composite membrane.

Alternatively, downstream of the sizing roller assembly, the protective film and the substrate may be passed through different guide rollers to the protective film take-up mechanism 42 and the substrate take-up mechanism 22, respectively, as shown in FIG. 3, to control the separation angle separation of the substrate and the composite film sheet. Specifically, the protective film reaches the protective film winding mechanism 42 after being guided by the fifth guide roller 55; the substrate sequentially passes through a ninth guide roller 59 and an eighth guide roller 58 to be guided and then reaches the substrate winding mechanism 22, and the routing between the ninth guide roller 59 and the eighth guide roller 58 is an S-shaped curve; the protective film and the substrate are separated from the composite membrane.

Referring to fig. 1-3, a protective film, a solid electrolyte film, electrode pole pieces, a solid electrolyte film and a protective film are sequentially distributed between the shaping roller assemblies. The protective film is transported from the upstream of the shaping roller assembly to the shaping roller assembly, passes through a gap between the shaping roller assembly and the solid electrolyte membrane and is rolled, and then continuously moves to the downstream of the shaping roller assembly until being recovered. Therefore, the protective film can be repeatedly utilized, reduces the damage to the environment while saving the production and manufacturing cost, and is also beneficial to improving the production efficiency.

In some embodiments, the protective film may be wound up and recovered downstream of the sizing roller assembly by separating the protective film from the composite pole pieces by a protective film winding mechanism 42.

In some embodiments, the recycled substrate may be wound up downstream of the sizing roller assembly by separating the substrate from the composite pole piece by a substrate winding mechanism 22.

In some embodiments, by providing the cooling roller 74 for cooling the composite pole piece, the temperature of the composite pole piece is reduced, and the production efficiency is higher compared with natural air cooling; at the same time, chill roll 74 also provides a sizing treatment for the composite pole piece.

As mentioned in the background art, the conventional shaping roller assembly has high strength and poor deformation resistance, and the electrode sheet is chamfered for smooth rolling process, so as to form a structure with thick middle and thin two ends. Because the transverse thickness of the electrode plate is inconsistent, when the solid electrolyte membrane is attached to the electrode plate, the edge area of the electrode plate is still in a separated state with the solid electrolyte membrane. When the rolling equipment carries out rolling lamination on the electrode pole piece and the solid electrolyte membrane, the electrode pole piece and the solid electrolyte membrane are difficult to be compounded tightly due to the fact that the rolling force of the steel roller is different in the middle area and the edge area of the electrode pole piece, namely ineffective compounding is achieved, the transverse compaction density of the compound pole piece is inconsistent, and meanwhile the consistency of the compound pole piece is poor. The electrode plate is severely broken, so that the safety performance and quality of the lithium ion battery are greatly affected.

The preparation facilities of compound pole piece of this application sets up heating mechanism and is used for carrying out preheating treatment to electrode pole piece, solid electrolyte membrane and protection film before the compound step of roll-in at shaping roller subassembly upper reaches, and the heating up has improved holistic compliance, more easily reaches the effect of inseparable complex in the compound in-process of follow-up roll-in, has improved the compound degree between electrode pole piece, solid electrolyte membrane and the protection film two by two.

By adopting the preparation device of the composite electrode plate, the protective film is attached to the two sides of the electrode plate and the solid electrolyte membrane before the rolling and compounding step, so that the protective effect is achieved, and in the rolling and compounding process, the stress conditions of the electrode plate and the solid electrolyte membrane in the rolling process are regulated through the buffer provided by the protective film, so that the solid electrolyte membrane can better cover the electrode plate; the transverse thickness of the electrode plate tends to be consistent after rolling, so that adverse effects on the rolling composite process caused by the phenomena of thick middle and thin two ends of the electrode plate are avoided, and the electrode plate is prevented from being crushed; and the stress of the electrode pole piece and the solid electrolyte membrane in the rolling process is uniform, the degree of compositing among the electrode pole piece, the solid electrolyte membrane and the protective film is improved, and the consistency of the transverse thickness of the composite pole piece is improved. In addition, the composite pole piece prepared by the preparation method is applied to the battery, so that the situation that the battery possibly falls off powder in the charge-discharge cycle process can be effectively prevented, the cycle performance of the battery is affected, and the overall safety performance of the battery is improved.

The composite process is carried out under dry conditions, which are different from the traditional wet electrode preparation method, wherein the traditional wet preparation method is used for preparing the composite electrode by firstly preparing solid electrolyte slurry, then coating the solid electrolyte slurry on an electrode plate or otherwise preparing the electrode slurry, and then coating the electrode slurry on a solid electrolyte membrane. The preparation process does not use solvent, so that the complicated drying step of the subsequent steps is avoided, and the production cost can be effectively reduced.

It is understood that the dry process refers to the preparation process of the relevant electrode plate and electrolyte membrane without adding solvent; solutions of minor amounts of liquid lubricants or other liquid additives possibly used during rolling are still within the scope of the present application.

In some embodiments, both the electrode sheet and the solid electrolyte membrane are prepared by a dry process.

In some embodiments, at least one of the electrode sheet and the solid electrolyte membrane is prepared by a dry process.

In some embodiments, both the electrode sheet and the solid electrolyte membrane are prepared by a wet process.

It will be appreciated that the electrode sheet and solid electrolyte membrane are preferably prepared under dry conditions, and thus, no solvent is required throughout the electrode preparation process.

It will be appreciated that the preparation process of the electrode sheet and the solid electrolyte membrane is independent of the preparation process of the composite electrode, i.e. if a wet process is used, the electrode sheet is subjected to the coating, baking and rolling processes.

In some embodiments, the electrode sheet is a positive electrode sheet. The positive electrode material, especially the high-nickel ternary material with higher energy density, is easy to generate unexpected side reaction with electrolyte, especially nonaqueous electrolyte, and the side reaction causes the reduction of battery performance and potential safety hazard; and the solid electrolyte layer is compounded on the surface of the positive electrode, so that the safety of the battery is improved.

The positive electrode sheet includes an active material layer and a current collector layer. When preparing the positive plate by a dry method, firstly stirring an active substance, a conductive agent and a binder to obtain a positive mixture; and (3) carrying out fibrosis treatment on the mixture to obtain a fibrosis mixture of the positive electrode, and carrying out rolling compounding on the fibrosis mixture of the positive electrode and a current collector layer to obtain the positive electrode plate.

In some embodiments, the method of fiberizing includes, but is not limited to, air milling, high speed stirring, mechanical fusion, twin screw extrusion, and the like.

The positive electrode active material layer is formed of a positive electrode active material containing one or more transition metal cations, such as manganese (Mn), nickel (Ni), cobalt (Co), chromium (Cr), iron (Fe), vanadium (V), and combinations thereof. The positive electrode active material layer has a thickness of greater than or equal to about 1 μm to less than or equal to about 1,000 μm.

The positive electrode active material is one of layered oxide, spinel, and polyanion. For example, a layered oxide (e.g., a rock salt layered oxide) comprises one or more lithium-based positive electrode active materials selected from the group consisting of: liCoO ₂ (LCO)，LiNi _x Mn _y Co ₁ -x-yO ₂ (wherein x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 1), and LiNi ₁ -x-yCo _x Al _y O ₂ (wherein x is more than or equal to 0 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 1), and LiNi _x Mn _1-x O ₂ (wherein 0.ltoreq.x.ltoreq.1), and Li _1+x MO ₂ (wherein M is one of Mn, ni, co and Al and 0.ltoreq.x.ltoreq.1). The spinel comprises one or more lithium-based positive electrode active materials selected from the group consisting of: liMn ₂ O ₄ (LMO) and LiNi _x Mn _1.5 O ₄ . Olivine-type positive electrode active material LiMPO containing one or more lithium-based positive electrode active materials ₄ (wherein M is at least one of Fe, ni, co and Mn). The polyanionic cation comprises, for example, a phosphate such as LiV ₂ (PO ₄ ) ₃ And/or silicates such as life io ₄ 。

In some embodiments, one or more lithium-based positive electrode active materials may optionally be coated (e.g., by LiNbO ₃ And/or Al ₂ O ₃ ) And/or can be usedDoped (e.g., by magnesium (Mg)). Further, in certain embodiments, one or more lithium-based positive electrode active materials may optionally be mixed with one or more conductive materials that provide an electron conduction path and/or at least one polymeric binder material that improves the structural integrity of the positive electrode. For example, the positive electrode active material layer may include greater than or equal to about 30 wt% to less than or equal to about 99 wt% of one or more lithium-based positive electrode active materials; greater than or equal to about 0 wt% to less than or equal to about 30 wt% of a conductive material; and greater than or equal to about 0 wt% to less than or equal to about 20 wt% of a binder.

In some embodiments, the binder comprises Polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile rubber (NBR), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, lithium alginate, and combinations thereof.

In some embodiments, the conductive material may include a carbon-based material, powdered nickel or other metal particles, or a conductive polymer. Carbon-based materials may include, for example, carbon black, graphite, acetylene black (e.g., KETCHENTM black or denktatm black), carbon fibers and particles of nanotubes, graphene, and the like. Examples of the conductive polymer include polyaniline, polythiophene, polyacetylene, polypyrrole, and the like.

It is to be understood that the above examples of positive electrode active materials, binders, and conductive materials are merely illustrative, and any known positive electrode active materials, binders, and conductive materials can be used in the present application without departing from the inventive concepts of the present application. And the addition of known additives based on actual use needs is also considered to be within the scope of the present application.

In some embodiments, both the front and back sides of the current collector layer comprise an active material layer.

In some embodiments, the current collector layer may employ a metal foil or a composite current collector.

For example, aluminum foil may be used as the metal foil.

The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base material.

Studies have shown that wet coating is often used in the conventional art, but since the positive electrode active slurry is a water-based slurry, protrusions are often generated at the edges of the active material layer during drying due to fluidity and surface tension of the slurry. Meanwhile, when the positive electrode active material layer is rolled, the edges of the active material layer are cracked directly due to rolling stress, so that the positive electrode active material layer is cracked, and finally the performance of the battery is influenced. In addition, the problems of expansion, too fast performance decay and the like occur in the long-time circulation process of the battery due to the fact that the moisture content is too high in wet coating.

In some embodiments, the electrode sheet is a negative electrode sheet.

The negative electrode tab is formed of a lithium host material (e.g., a negative electrode active material) that can be used as a negative electrode terminal of a lithium ion battery. In various aspects, the negative electrode tab may be defined by a plurality of negative electrode active material particles. Such anode active material particles may be disposed in one or more layers so as to define the three-dimensional structure of the anode. In certain embodiments, the negative electrode may also include an electrolyte 50, such as a plurality of electrolyte particles (not shown).

In some embodiments, the negative electrode tab may be a negative electrode active material comprising lithium, including, for example, lithium metal and/or lithium alloy.

The negative electrode sheet may be a silicon-based negative active material comprising, for example, a silicon alloy, silicon oxide, or a combination thereof, which may also be mixed with graphite in some cases.

The negative electrode sheet may be a carbonaceous-based negative electrode active material comprising one or more of graphite, graphene, carbon Nanotubes (CNT), and combinations thereof.

The negative electrode sheet may also include one or more negative active materials that accept lithium, such as lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ ) One or more transition metals (e.g., tin (Sn)), one or more metal oxides (e.g., vanadium oxide (V) ₂ O ₅ ) Tin oxide (SnO), titanium dioxide (TiO) ₂ ) Titanium niobium oxide (TixNbyOz, where 0.ltoreq.x.ltoreq.2, 0.ltoreq.y.ltoreq.24, and 0.ltoreq.z.ltoreq.64), metal alloys (such as copper-tin alloys (Cu) ₆ Sn ₅ ) And one or more metal sulfides such as iron sulfide (FeS).

Alternatively, the negative active material in the negative electrode sheet may be doped with one or more conductive materials that provide an electron conduction path and/or at least one polymeric binder material that improves the structural integrity of the negative electrode. For example, the anode active material may be doped with a binder such as: poly (tetrafluoroethylene) (PTFE), sodium carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), nitrile-butadiene rubber (NBR), styrene-butylene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, lithium alginate, and combinations thereof.

The conductive material may include carbon-based materials, powdered nickel or other metallic particles, or conductive polymers. The carbon-based material may include, for example, particles of carbon black, graphite, superP, acetylene black (such as KETCHENTM black or denktatm black), carbon fibers and nanotubes, graphene, and the like. Examples of the conductive polymer include polyaniline, polythiophene, polyacetylene, polypyrrole, poly (3, 4-ethylenedioxythiophene) polysulfstyrene, and the like.

The negative electrode sheet may include greater than or equal to about 50 wt% to less than or equal to about 99 wt% of a negative electrode active material, alternatively greater than or equal to about 0 wt% to less than or equal to about 60 wt% of a solid state electrolyte, alternatively greater than or equal to about 0 wt% to less than or equal to about 15 wt% of a conductive material, and alternatively greater than or equal to about 0 wt% to less than or equal to about 10 wt% of a binder.

In some embodiments, the solid electrolyte membrane includes a solid electrolyte and a binder.

When preparing the solid electrolyte membrane, firstly, stirring and mixing the solid electrolyte and the binder, and carrying out fibrosis treatment on the mixture to obtain a fibrosis solid electrolyte mixture, wherein the fibrosis solid electrolyte mixture is pressed by rolling to obtain the solid electrolyte membrane.

In some embodiments, the solid state electrolyte is an inorganic solid state electrolyte including one or more of an oxide solid state electrolyte, a sulfide solid state electrolyte, a halide solid state electrolyte, a hydride solid state electrolyte, a boride solid state electrolyte, and a nitride solid state electrolyte.

The oxide solid electrolyte comprises one or more garnet ceramics, LISICON-type oxides, NASICON-type oxides, and perovskite-type ceramics. For example, one or more garnet ceramics include, but are not limited to, li _6.5 La ₃ Zr _1.75 Te _0.25 O ₁₂ 、Li ₇ La ₃ Zr ₂ O ₁₂ 、Li _6.2 Ga _0.3 La _2.95 Rb _0.05 Zr ₂ O ₁₂ 、Li _6.85 La _2.9 Ca _0.1 Zr _1.75 Nb _0.25 O ₁₂ 、Li _6.25 Al _0.25 La ₃ Zr ₂ O ₁₂ 、Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂ One or more of the following. One or more LISICON-type oxides include, but are not limited to, li ₁₄ Zn(GeO ₄ ) ₄ 、Li _3+x (P ₁ -xSi _x )O ₄ (wherein 0<x<1)、Li _3+x Ge _x V ₁ -xO ₄ (wherein 0<x<1) One or more of the following. One or more NASICON-type oxides may be formed from LiMM' (PO ₄ ) ₃ And a definition wherein M and M' are independently selected from Al, ge, ti, sn, hf, zr and La. For example, in certain variations, the one or more NASICON-type oxides include, but are not limited to, li _1+x Al _x Ge ₂ -x(PO ₄ ) ₃ (LAGP) (wherein 0.ltoreq.x.ltoreq.2), li _1+x Al _x Ti ₂ -x(PO ₄ ) ₃ (LATP) (where 0.ltoreq.x.ltoreq.2), li ₁₊ _x Y _x Zr ₂ -x(PO ₄ ) ₃ (LYZP) (wherein 0.ltoreq.x.ltoreq.2), li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ 、LiTi ₂ (PO ₄ ) ₃ 、LiGeTi(PO ₄ ) ₃ 、LiGe ₂ (PO ₄ ) ₃ 、LiHf ₂ (PO ₄ ) ₃ One or more of the following. One or more perovskite-type ceramics including, but not limited to, li _3.3 La _0.53 TiO ₃ 、LiSr _1.65 Zr _1.3 Ta _1.7 O ₉ 、Li _2x-y Sr _1-x Ta _y Zr _1-y O ₃ (wherein x=0.75 y and 0.60<y<0.75)、Li _3/8 Sr _7/16 Nb _3/4 Zr _1/4 O ₃ 、Li _3x La _(2/3-x) TiO ₃ (wherein 0<x<0.25 One or more of the following).

Sulfide solid state electrolytes include, but are not limited to, li ₂ S-P ₂ S ₅ 、Li ₂ S-P ₂ S ₅ -MS _x (wherein M is Si, ge and Sn and 0.ltoreq.x.ltoreq.2), li _3.4 Si _0.4 P _0.6 S ₄ 、Li ₁₀ GeP ₂ S _11.7 O _0.3 、Li _9.6 P ₃ S ₁₂ 、Li ₇ P ₃ S ₁₁ 、Li ₉ P ₃ S ₉ O ₃ 、Li _10.35 Si _1.35 P _1.65 S ₁₂ 、Li _9.81 Sn _0.81 P _2.19 S ₁₂ 、Li ₁₀ (Si _0.5 Ge _0.5 )P ₂ S ₁₂ 、Li(Ge _0.5 Sn _0.5 )P ₂ S ₁₂ 、Li(Si _0.5 Sn _0.5 )PsS ₁₂ 、Li ₁₀ GeP ₂ S ₁₂ (LGPS)、Li ₆ PS ₅ X (wherein X is Cl, br or I), li ₇ P ₂ S ₈ I、Li _10.35 Ge _1.35 P _1.65 S ₁₂ 、Li _3.25 Ge _0.25 P _0.75 S ₄ 、Li ₁₀ SnP ₂ S ₁₂ 、Li ₁₀ SiP ₂ S ₁₂ 、Li _9.54 Si _1.74 P _1.44 S _11.7 C _l0.3 、 _(1-x) P ₂ S _5-x Li ₂ S (wherein 0.5.ltoreq.x.ltoreq.0.7).

Halide solid electrolyteIncluding but not limited to Li ₂ CdC _l4 、Li ₂ MgC _l4 、Li ₂ Cd _I4 、Li ₂ ZnI ₄ 、Li ₃ OCl、LiI、Li ₅ ZnI ₄ 、Li ₃ OCl _1-x Br _x (wherein 0<x<1) One or more of (a) and (b).

Boride solid state electrolytes include, but are not limited to, li ₂ B ₄ O ₇ 、Li ₂ O-(B ₂ O ₃ )-(P ₂ O ₅ ) One or more of (a) and (b).

Nitride solid state electrolytes including but not limited to Li ₃ N、Li ₇ PN ₄ 、LiSi ₂ N ₃ One or more of LiPON.

The hydride solid state electrolyte includes, but is not limited to, li ₃ AlH ₆ 、LiBH ₄ 、LiBH ₄ -LiX (wherein X is one of Cl, br and I), liNH ₂ 、Li ₂ NH、LiBH ₄ -LiNH ₂ One or more of (a) and (b).

In some embodiments, the inorganic solid state electrolyte may be one or more metal oxide particles or lithium-containing compounds, including but not limited to Al ₂ O ₃ 、SiO ₂ 、TiO ₂ 、LiNbO ₃ 、Li ₄ Ti ₅ O ₄ 、Li ₃ PO ₄ One or more of the following.

In some embodiments, the solid state electrolyte further includes a portion of a polymer solid state electrolyte, a composite solid state electrolyte comprised of a polymer solid state electrolyte and an inorganic solid state electrolyte. In the embodiment of the application, the mass ratio of the inorganic solid electrolyte and the polymer solid electrolyte in the composite solid electrolyte is not particularly required, and a user can design according to actual needs. Wherein, the polymer solid electrolyte can be at least one of polyvinyl chloride (PVC), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA) and polyethylene oxide (PEO).

In some embodiments, the lithium salt is included in the polymer solid electrolyte.

In some embodiments, the lithium salt includes, but is not limited toLithium hexafluorophosphate (LiPF) ₆ ) The method comprises the steps of carrying out a first treatment on the surface of the Lithium perchlorate (LiClO) ₄ ) Lithium tetrachloroaluminate (LiAlCl) ₄ ) Lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF) ₄ ) Lithium difluorooxalato borate (LiBF) ₂ (C ₂ O ₄ ) (LiODFB), lithium tetraphenylborate (LiB (C) ₆ H ₅ ) ₄ ) Lithium bis (oxalato) borate (LiB (C) ₂ O ₄ ) ₂ ) Lithium tetrafluorooxalate phosphate (LiPF) ₄ (C ₂ O ₄ ) (LiFeP), lithium nitrate (LiNO) ₃ ) Lithium hexafluoroarsenate (LiAsF) ₆ ) Lithium triflate (LiCF) ₃ SO ₃ ) Lithium bis (trifluoromethanesulfonyl imide) (LITFSI) (LiN (CF) ₃ SO ₂ ) ₂ ) Lithium bis (fluorosulfonyl imide) (LiN (FSO) ₂ ) ₂ ) (LIFSI) and combinations thereof. In certain variations, the lithium salt is selected from lithium hexafluorophosphate (LiPF ₆ ) Lithium bis (trifluoromethanesulfonyl imide) (LiTFSI) (LiN (CF) ₃ SO ₂ ) ₂ ) Lithium bis (fluorosulfonyl imide) (LiN (FSO) ₂ ) ₂ ) (LiFSI), lithium fluoroalkylphosphonate (LiFAP), lithium phosphate (Li) ₃ PO ₄ ) One or more of the following.

It is to be understood that the above-mentioned terms including oxide solid electrolyte, sulfide solid electrolyte, halide solid electrolyte, hydride solid electrolyte, nitride solid electrolyte, polymer solid electrolyte, etc. are all known in the art, and the above-mentioned materials are merely illustrative examples, and not limiting the scope of protection, and any known solid electrolyte type can be used in the present application without departing from the inventive concept of the present application.

Preferably, the thickness of the solid electrolyte membrane is 1 to 30 μm; preferably 3-20 μm; more preferably 3-15 μm.

The application of a solid electrolyte coating to the electrode surface, particularly the surface of a positive electrode of high capacity, can effectively improve the safety performance of the battery. But is limited by the energy density, the thickness of the solid electrolyte membrane is generally thin, which is an order of magnitude smaller than the dry-process electrode sheet, which makes the solid electrolyte membrane susceptible to cracking when the electrode sheet is dry-process compounded.

In some embodiments, the solid electrolyte membrane is formed separately, i.e., the solid electrolyte membrane is formed without the aid of a substrate and the membrane remains intact.

In some embodiments, the side of the solid electrolyte membrane remote from the electrode pads is covered with a substrate having a lower binding force to the solid electrolyte membrane than to the electrode pads. After rolling, at least a portion of the solid electrolyte is transferred to the electrode and separated from the substrate.

In some embodiments, the electrode sheet and solid electrolyte membrane may also be purchased.

The application also provides a composite pole piece, which is prepared according to the preparation method of the composite pole piece.

The application also provides a lithium ion battery, which comprises the composite pole piece.

The process of manufacturing the composite pole piece based on the manufacturing apparatus of the composite pole piece of the present application will be described more specifically by way of examples. However, embodiments of the present application are not limited to these examples only.

Example 1.

The preparation device of the composite pole piece shown in fig. 1 is used for compositing the positive pole piece and two layers of solid electrolyte membranes, so that the solid electrolyte membranes are composited on the positive active material layers on the two sides of the positive pole piece at the same time. The solid electrolyte membrane is covered with a base material. Wherein the protective film is PE-based non-woven fabric.

The electrode pole piece starts from the electrode pole piece unreeling mechanism 11 and passes through the first guide roller 51 to reach the first heating roller 71; the solid electrolyte membrane positioned on the upper side of the electrode pole piece unreeling mechanism 11 starts from the solid electrolyte membrane unreeling mechanism 21, is guided by the first guide roller 51 and reaches the first heating roller 71; the solid electrolyte membrane positioned at the lower side of the electrode pole piece unreeling mechanism 11 starts from the solid electrolyte membrane unreeling mechanism 21, is guided by the second guide roller 52 and the first guide roller 51 and then reaches the first heating roller 71; the protective film on the upper side of the electrode sheet unreeling mechanism 11 starts from the protective film unreeling mechanism 41, and reaches the first heating roller 71 after being guided by the third guide roller 53; the protective film positioned at the lower side of the electrode pole piece unreeling mechanism 11 starts from the protective film unreeling mechanism 41, and reaches the first heating roller 71 after being guided by the third guide roller 53, the second guide roller 52 and the first guide roller 51; the protective film, the solid electrolyte film, the electrode pole piece, the solid electrolyte film and the protective film are firstly attached and preheated at the first heating roller 71 to obtain an attaching piece; then the bonding sheet is preheated by a second heating roller 72 and a third heating roller 73, guided by a fourth guiding roller 54, reaches a shaping roller assembly, and is pressed down by rollers of the first shaping roller 31 and the second shaping roller 32 through a gap between the first shaping roller 31 and the second shaping roller 32 to complete the compounding of the protective film, the solid electrolyte film, the electrode pole piece, the solid electrolyte film and the protective film, so as to obtain a composite membrane; the protective film and the base material are guided by a fifth guide roller 55 and then respectively reach the protective film winding mechanism 42 and the base material winding mechanism 22, and the protective film and the base material are separated from the composite membrane to obtain a composite pole piece; the composite pole piece reaches the cooling roller 74 after being guided by the sixth guide roller 56, and reaches the composite pole piece winding mechanism 12 after being guided by the seventh guide roller 57, so as to finish winding the composite pole piece.

Example 2.

This example differs from example 1 only in the manner in which the base material is separated from the composite pole piece downstream of the sizing roller assembly.

As shown in fig. 2, downstream of the shaping roller assembly, the protective film is guided by the fifth guide roller 55 and then reaches the protective film winding mechanism 42, and the protective film winding mechanism 42 separates the protective film from the composite film sheet and completes winding; the substrate reaches the substrate winding mechanism 22 after being guided by the ninth guide roller 59 and the eighth guide roller 58, the wiring between the ninth guide roller 59 and the eighth guide roller 58 is a straight line, and the substrate winding mechanism 22 separates the substrate from the composite membrane and completes winding.

Example 3.

As shown in fig. 3, downstream of the shaping roller assembly, the protective film is guided by the fifth guide roller 55 and then reaches the protective film winding mechanism 42, and the protective film winding mechanism 42 separates the protective film from the composite film sheet and completes winding; the substrate reaches the substrate winding mechanism 22 after being guided by the ninth guide roller 59 and the eighth guide roller 58, the routing between the ninth guide roller 59 and the eighth guide roller 58 is in an S-shaped curve, and the substrate winding mechanism 22 separates the substrate from the composite membrane and completes winding.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims

1. A device for preparing a composite pole piece, the device comprising:

the shaping roller assembly comprises a first shaping roller and a second shaping roller, and is used for carrying out rolling compounding on the electrode pole piece, the solid electrolyte membrane and the protective film to form the composite pole piece;

2. The apparatus for preparing a composite pole piece of claim 1, further comprising a composite pole piece winding mechanism downstream of the sizing roller assembly for receiving the composite pole piece.

3. The apparatus for preparing a composite pole piece according to claim 2, further comprising a substrate winding mechanism positioned between the shaping roller assembly and the composite pole piece winding mechanism for receiving a substrate coated on the solid electrolyte membrane;

4. The device for manufacturing a composite pole piece according to claim 3, further comprising a protective film winding mechanism positioned between the shaping roller assembly and the base material winding mechanism for receiving the protective film.

5. The apparatus for producing a composite pole piece according to any one of claims 1 to 4, wherein the protective film is a polymer film or a nonwoven fabric.

6. The apparatus according to any one of claims 1 to 4, wherein the time for preheating the electrode sheet, the solid electrolyte membrane, and the protective film by the heating mechanism is not less than 2S.

7. The apparatus according to any one of claims 1 to 4, wherein the number of the heating means is plural, and the heating means is configured to preheat the electrode sheet, the solid electrolyte membrane and the protective film simultaneously plural times, and the preheating temperature is successively increased.

8. The apparatus for manufacturing a composite pole piece according to any one of claims 1 to 4, wherein the number of the solid electrolyte membrane unreeling mechanisms is two, and the solid electrolyte membrane unreeling mechanisms are symmetrically arranged at both sides of the electrode pole piece unreeling mechanism.

9. A composite pole piece, characterized in that it is produced by the production device according to any one of claims 1-8.

10. A lithium ion battery comprising the composite pole piece of claim 9.