CN214957015U

CN214957015U - Lithium ion battery preparation system

Info

Publication number: CN214957015U
Application number: CN202120510568.3U
Authority: CN
Inventors: 王宏栋
Original assignee: Qinxin Group Tianjin New Energy Technology Research Institute Co ltd
Current assignee: Qinxin Group Tianjin New Energy Technology Research Institute Co ltd
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2021-11-30
Anticipated expiration: 2031-03-10

Abstract

The utility model relates to a battery field discloses a lithium ion battery preparation system, wherein, lithium ion battery preparation system includes third equipment (300), third equipment (300) are including being used for toasting vacuum tunnel of electricity core toasts unit (310), is used for toasting the back electricity core (400) annotate liquid, become annotate liquid that becomes-become unit (320) and be used for with electricity core (400) are capsulated into encapsulation unit (380) of shell. The battery cell is injected and formed by the third equipment before the battery cell is packaged into the shell, so that the battery cell is not limited by the packaging of the battery cell during the operations such as injection, formation and the like, and the injection and formation effects can be improved.

Description

Lithium ion battery preparation system

Technical Field

The utility model relates to a battery field specifically relates to lithium ion battery preparation system.

Background

In the existing lithium ion battery preparation process, the production process is multiple, and the automation degree is low. Harmful impurities may be brought in during the storage and transportation of raw materials, manual operation and complex manual operation exist in a plurality of processes, and human factors and environmental factors have great influence on the performance and safety performance of the battery.

In addition, in the liquid injection formation stage of the battery cell, the battery cell and the cover plate are generally assembled first, and then the battery cell is placed into the casing and the cover plate are welded to complete the encapsulation (i.e., casing) of the battery cell and form the battery unit. And then, baking, injecting, forming and the like are carried out on the battery unit. During liquid injection, the liquid is injected through a small hole reserved in the cover plate, a rubber plug is plugged in the small hole after the liquid is injected, formation is carried out again, then the rubber plug is taken down for secondary liquid injection and liquid supplementation, and finally the small hole is sealed. After the injection is completed, the priming (i.e., formation) is performed. In other words, the existing pre-charging and liquid injection are performed separately, the duty ratio of the battery core in the shell is designed to be large in order to exert the capacity of the battery, the space reserved for injecting the electrolyte is small, the pole piece soaks and absorbs the electrolyte after only one-time liquid injection, and secondary liquid injection or liquid supplement is performed after the space is reserved. Therefore, the pole piece soaking effect is not uniform, namely, the pole piece is well soaked in the place before pre-charging, and the electrolyte is not available in the place at all, so that the place at all is well activated during pre-charging, and the place at all is not activated, and the formation or stable consistency of an SEI film on an active material interface can not be achieved. In addition, in the existing preparation method of the lithium ion battery, the battery is charged and has higher charge amount during secondary liquid injection or liquid supplement, and the operation process is also very unsafe. Moreover, the preparation method has a very complicated flow, and the battery is seriously polluted by contacting the electrolyte and plugging the rubber plug for many times.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the problem that the degree of automation that prior art exists is low, annotate the liquid activation homogeneity relatively poor, providing a lithium ion battery preparation system.

In order to achieve the above object, an aspect of the present invention provides a lithium ion battery preparation system, wherein the lithium ion battery preparation system includes a third device, the third device includes a vacuum tunnel baking unit for baking the battery cell, a liquid injection-formation unit for injecting, forming and an encapsulation unit for encapsulating the battery cell into the shell, wherein the vacuum tunnel baking unit is used for baking the battery cell.

Optionally, the lithium ion battery preparation system includes a first device, a second device, and the third device that are sequentially arranged, where the first device is used to manufacture a pole piece, and the second device is used to manufacture the pole piece manufactured by the first device into the battery cell.

Optionally, the first equipment comprises a pole piece preparation unit, and the pole piece preparation unit comprises a feeding device, a raw material classifier, a first iron removal device, a raw material buffer tank, a second iron removal device, a stirring device, a slurry storage tank and a coating, rolling and slitting integrated machine which are sequentially connected through a pipeline.

Optionally, the first device includes two pole piece preparation units for preparing a positive pole piece and a negative pole piece respectively.

Optionally, the second device comprises a winding pre-pressing unit, a hot-press forming unit, a cold-press shaping unit, a tab cutting unit and a battery core assembling unit which are sequentially arranged.

Optionally, the winding pre-pressing unit, the hot press molding unit, the cold press molding unit, the tab cutting unit and the battery cell assembling unit are connected through a conveyer belt.

Optionally, the first device, the second device and the third device are arranged for continuous operation.

Optionally, the liquid injection-formation unit comprises a first tank body with an open top, a first upper cover capable of sealing the open top of the first tank body, a second tank body with an open top, a second upper cover capable of sealing the open top of the second tank body, a tray capable of lifting in the first tank body and a formation device capable of lifting in the second tank body, wherein the first tank body is provided with a first interface for sucking and/or breaking vacuum, and the second tank body is provided with a second interface for sucking and/or breaking vacuum.

Optionally, the liquid injection-formation unit comprises a third tank body for soaking the formed battery core to form a gel polymer electrolyte on the surface of the battery core, and a curing device for curing the gel polymer electrolyte.

Optionally, the third apparatus includes an electrolyte supply unit for supplying electrolyte to the injection-formation unit, a first filtering device disposed between the electrolyte supply unit and the injection-formation unit, an electrolyte buffer tank, an electrolyte recovery unit for recovering the electrolyte of the injection-formation unit, and a second filtering device disposed between the electrolyte recovery unit and the electrolyte buffer tank, where the electrolyte buffer tank has a first inlet and a second inlet respectively connected to the first filtering device and the second filtering device, and an outlet connected to the injection-formation unit.

Through the technical scheme, the battery cell can be subjected to liquid injection and formation treatment before the battery cell is packaged into the shell, so that the liquid injection, formation and other operations can be ensured without being limited by the battery cell packaging, and the liquid injection and formation effects can be improved.

Drawings

Fig. 1 is a schematic structural diagram illustrating an embodiment of a pole piece preparation unit of a first apparatus of the present invention;

FIG. 2 is a schematic diagram illustrating the structure of one embodiment of a second apparatus of the present invention;

FIG. 3 is a schematic diagram illustrating the structure of one embodiment of a third apparatus of the present invention;

fig. 4 is a schematic view of the first tank body of the injection-formation unit in fig. 3 being supplied with an electrolyte for infiltration;

fig. 5 is a schematic diagram of the formation of the battery cell in the second groove.

Description of the reference numerals

100-first equipment, 110-feeding device, 120-raw material classifier, 121-unqualified material storage tank, 130-first iron removal device, 140-raw material buffer tank, 150-second iron removal device, 160-stirring device, 161-conductive agent feeder, 162-adhesive feeder, 163-third iron removal device, 170-slurry storage tank, 180-coating, rolling and slitting integrated machine, 190-pole piece storage, 200-second equipment, 210-winding and prepressing unit, 220-hot press molding unit, 230-cold press molding unit, 240-pole lug cutting unit, 250-electric core assembling unit, 300-third equipment, 310-vacuum tunnel baking unit, 320-liquid injection-molding unit, 321-first groove body, 3211-first interface, 322-first upper cover, 323-second tank, 3231-second interface, 324-second upper cover, 325-tray, 326-formation device, 3261-probe, 3262-lead, 3263-second lifting mechanism, 327-monitoring unit, 328-bracket, 330-electrolyte supply unit, 331-third filtering device, 332-electrolyte barrel, 340-first filtering device, 350-electrolyte buffer tank, 360-electrolyte recovery unit, 361-fourth filtering device, 362-electrolyte recovery barrel, 370-second filtering device, 380-packaging unit, 400-cell, 410-isolation ring, 420-cell upper cover plate.

Detailed Description

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.

In the present invention, unless otherwise specified, the use of directional terms such as "upper, lower, left, and right" generally means upper, lower, left, and right as illustrated with reference to the accompanying drawings; "inner and outer" refer to the inner and outer relative to the profile of the components themselves. The present invention will be described in detail with reference to the accompanying drawings in conjunction with embodiments.

The utility model provides a lithium ion battery preparation system, wherein, lithium ion battery preparation system includes third equipment 300, third equipment 300 can be including being used for toasting the vacuum tunnel of electricity core toasts unit 310, is used for toasting the back electricity core 400 annotates liquid, the notes liquid that becomes become unit 320 and be used for with electricity core 400 encapsulates the encapsulation unit 380 of income shell.

The utility model discloses can annotate liquid, become the processing to electric core through third equipment 300 before encapsulating the shell with electric core, can ensure to annotate the restriction that does not receive electric core encapsulation when the operation such as liquid, formation, can improve the effect of annotating liquid, formation.

Additionally, the utility model discloses a lithium ion battery preparation system including first equipment 100, second equipment 200 that set gradually and third equipment 300, first equipment 100 is used for making the pole piece, second equipment 200 be used for with the pole piece of first equipment 100 preparation is makeed into electricity core 400. By dividing the preparation of the lithium ion battery into three sections by the first apparatus 100, the second apparatus 200, and the third apparatus 300, the degree of automation can be improved (in the first apparatus, the second apparatus, and the third apparatus, all of which operate continuously).

Wherein the first apparatus 100, the second apparatus 200, and the third apparatus 300 are each continuously operated apparatuses. By setting the operation parameters and the like, the first device 100, the second device 200 and the third device 300 can be set to be operated continuously, that is, the first device 100, the second device 200 and the third device 300 are matched to run continuously, so that the whole lithium ion battery preparation system runs continuously.

The first equipment 100 is used for preparing pole pieces, as shown in fig. 1, the first equipment 100 may include a pole piece preparation unit, and the pole piece preparation unit includes a feeding device 110, a raw material classifier 120, a first iron removal device 130, a raw material buffer tank 140, a second iron removal device 150, a stirring device 160, a slurry storage tank 170, and a coating, rolling, slitting and integrating machine 180, which are sequentially connected by a pipeline.

Specifically, the feeding device 110 may be connected to the raw material classifier 120 through a pipeline to screen the raw material through the raw material classifier 120, the qualified material is sent to the first iron removing device 130 through a pipeline to remove iron in the raw material, and the unqualified material is sent to the unqualified material storage tank 121 to be stored. The first iron removing device 130 is connected to the raw material buffer tank 140 through a pipeline, so as to send the iron-removed raw material to the raw material buffer tank 140 for production and use. When pole pieces are continuously prepared, the raw materials in the raw material buffer tank 140 are conveyed to the second iron removal device 150 through a pipeline for secondary iron removal, and the second iron removal device 150 conveys the iron-removed raw materials to the stirring device 160 through a pipeline. The stirring device 160 comprises a stirring main body, a conductive agent feeder 161, a binder feeder 162 and a third iron removal device 163, the second iron removal device 150 feeds the raw materials to the stirring main body through a pipeline, and the conductive agent feeder 161 and the binder feeder 162 respectively feed the conductive agent and the binder to the stirring main body so as to stir the raw materials, the conductive agent and the binder into slurry through the stirring main body. The outlet of the stirring main body sends the slurry to a third iron removal device 163 for iron removal through a pipeline, and the third iron removal device 163 sends the iron-removed slurry to a slurry storage tank 170 through a pipeline. The slurry in the slurry storage tank 170 is further homogenized and the proportioning of the slurry, including stability, is better improved. The slurry in the slurry storage tank 170 is fed into the coating, rolling and slitting all-in-one machine 180 through a feeding device to complete the processes of coating the slurry on the current collector, rolling and slitting into pole pieces. The prepared pole pieces can be stored in the pole piece storage 190, so that continuous operation can be realized.

In the first equipment 100, all devices are connected through pipelines, and materials are conveyed through pipelines to reduce pollution and simultaneously obtain secondary treatment, so that the consistency of raw material indexes is ensured, and the consistency of the performance of the lithium ion battery is facilitated.

Wherein, in order to continuously operate the whole system, the first apparatus 100 includes two of the pole piece preparation units for preparing a positive pole piece and a negative pole piece, respectively. The pole piece reservoirs 190 of the two pole piece preparation units may provide the positive pole piece and the negative pole piece, respectively, to the subsequent second device 200.

As shown in fig. 2, the second device 200 includes a winding pre-pressing unit 210, a hot press forming unit 220, a cold press shaping unit 230, a tab cutting unit 240 and a battery core assembling unit 250, which are sequentially disposed. The winding prepressing unit 210 is used for winding the positive electrode sheet, the negative electrode sheet and the separator into the battery cell 400 and prepressing the battery cell. The hot press molding unit 220 is configured to hot press mold the pre-pressed battery cell 400. The cold press molding unit 230 is configured to cold press mold the battery cell 400 formed by hot press molding, so that the battery cell 400 reaches a desired size. The tab cutting unit 240 is used for cutting the positive electrode and the negative electrode of the battery cell 400 to form a tab. The cell assembling unit 250 is configured to weld a positive electrode tab and a negative electrode tab, mount a plastic casing on the welded cell 400, and weld a battery cap on the tabs.

In order to facilitate continuous operation among the units, the winding pre-pressing unit 210, the hot press molding unit 220, the cold press molding unit 230, the tab cutting unit 240 and the cell assembling unit 250 are connected through a conveyer belt.

The utility model discloses an in the third equipment 300, the vacuum tunnel toasts unit 310 can include the vacuum tunnel toasts the stove, and electric core 400 gets rid of moisture at the in-process that passes the vacuum tunnel toasts the stove.

The liquid injection-formation unit 320 may take various suitable forms, and in the embodiment shown in fig. 4 and 5, the liquid injection-formation unit 320 may include a first groove 321 having an open top, a first upper cover 322 capable of sealing the opening of the first groove 321, a second groove 323 having an open top, a second upper cover 324 capable of sealing the opening of the second groove 323, a tray 325 capable of being lifted and lowered in the first groove 321, and a formation device 326 capable of being lifted and lowered in the second groove 323, the first groove 321 is provided with a first port 3211 for sucking and/or breaking vacuum, and the second groove 323 is provided with a second port 3231 for sucking and/or breaking vacuum.

In this embodiment, the infiltration and formation are performed within the first and

second channel bodies

321, 323, respectively. Specifically, as shown in fig. 4 and 5, the tray 325 is used to support the battery cell 400. By setting the tray 325 to be capable of lifting, the position of the battery cell 400 can be lowered to a proper position in the first tank 321 during infiltration, for example, the isolation ring 410 of the battery cell 400 is just above the liquid level L of the electrolyte S in the first tank 321 during infiltration, so as to expose the upper cover plate 420 of the battery cell; prior to formation, the cell 400 may be lifted off of the electrolyte.

Among them, the tray 325 may include a tray main body and a first elevating mechanism for elevating the tray main body. The tray main body is driven to ascend and descend by the first lifting mechanism, so that the position of the battery cell 400 in the first groove body 321 can be conveniently adjusted.

In addition, the top opening of the first groove 321 can be covered by the first upper cover 322, so as to keep the inside of the first groove 321 in a sealed state during infiltration, and the inside of the first groove 321 is vacuumized or pressurized through the first port 3211.

The formation device 326 may be disposed at an appropriate position of the second groove 323 as needed. For convenience of operation, the forming device 326 is preferably liftably mounted to the second upper cover 324. Thus, the chemical conversion device 326 can be lowered during chemical conversion, and the chemical conversion device 326 can be raised during wetting so as not to interfere with each other. Specifically, as shown in fig. 5, the formation device 326 may include a probe 3261 for connecting with the battery cell 400, a wire 3262 for connecting the probe 3261 with an external power supply, and a second lifting mechanism 3263 for lifting the probe 3261. The second elevating mechanism 3263 includes a fixed portion attached to the second upper cover 324, and an elevating portion movable relative to the fixed portion, and the probe 3261 and the lead wire 3262 are fixed to the movable portion. When the device is used, the second lifting mechanism 3263 lifts the probe 3261 and the lead 3262 to avoid interference and infiltration during infiltration; during formation, the second lifting mechanism 3263 lowers the probe 3261 and the wire 3262 so that the probe 3261 contacts with the electrode column of the battery cell 400, and formation is performed; after formation is completed, the second elevating mechanism 3263 raises the probe 3261 and the wire 3262 to separate the probe 3261 from contact with the electrode.

To perform formation in the second groove 323, the second groove 323 is provided with a second port 3231 to evacuate. In addition, in order to facilitate the placement of the battery cell 400, a bracket 328 is disposed in the second groove 323, and the bracket 328 may be fixedly disposed or disposed in a liftable structure similar to the tray 325. In addition, in order to supplement the loss of the electrolyte at the time of infiltration, the third apparatus 300 includes an electrolyte supply unit 330 for supplying the electrolyte to the injection-formation unit (the first tank 321), and a first filtering device 340 disposed between the electrolyte supply unit 330 and the injection-formation unit. The first filtering device 340 is used for filtering the gas in the electrolyte, and in addition, Li + Al in the first filtering device 340 can pass through₂O₃Replenishing the aluminum in the electrolyte and removing moisture.

The third apparatus 300 may include an electrolyte buffer tank 350, an electrolyte recovery unit 360 for recovering the electrolyte of the injection-formation unit, and a second filtering device 370 disposed between the electrolyte recovery unit 360 and the electrolyte buffer tank 350, the electrolyte buffer tank 350 having a first inlet and a second inlet respectively connecting the first filtering device 340 and the second filtering device 370, and an outlet connecting the injection-formation unit. The electrolyte recovered by the electrolyte recovery unit 360 is purified and supplied with lithium through the second filtering device 370 to meet the standard of reuse, so that it can be merged with the electrolyte filtered by the first filtering device 340 and supplied from the electrolyte supply unit 330 in the electrolyte buffer tank 350 for standby.

In addition, the third apparatus 300 includes a monitoring unit 327 for monitoring a liquid level in the first tank 321, and the electrolyte supply unit 330 is operated according to a signal of the monitoring unit 327. Here, the first lifting mechanism may be configured to move within a predetermined height range, for example, the lowest position is such that the isolation ring 410 of the battery cell 400 is located above the liquid level L. According to the stroke of the first lifting mechanism and the specific specification of the battery cell 400, a predetermined liquid level in the first tank 321 may be set so as to be monitored by the monitoring unit 327, so that the electrolyte is supplied into the first tank 321 through the electrolyte supply unit 330 when the actual liquid level L is lower than the predetermined liquid level.

The monitoring unit 327 may be a proximity switch, etc. The electrolyte supply unit 330 may include a receiving chamber receiving the electrolyte, a pumping part pumping the electrolyte, and a liquid inlet pipe and a liquid delivery pipe connected to the first tank 321, respectively.

In addition, in order to further improve the impregnation effect, the battery cell 400 may be immersed in the electrolyte for a predetermined time in a vacuum state, and then high-purity nitrogen gas may be introduced to break the vacuum and sufficiently impregnate the battery cell 400.

By immersing the battery cell 400 in a vacuum state, it is possible to substantially exhaust gas remaining in the micropores of the separator of the battery cell 400 so as to inject the electrolyte into the micropores. The predetermined time may be set according to the type of the battery, and may be, for example, 10 seconds or less. In addition, before being soaked in the electrolyte, the battery cell 400 may be kept in a vacuum state for a certain time (which may be set according to the type of the battery, etc., and may be, for example, 8 hours or less) to completely remove moisture inside the battery cell 400.

Vacuum can be broken through introducing high-purity nitrogen, pressure is applied to the electrolyte, the electrolyte is sucked into the micropores of the diaphragm under the action of the high-purity nitrogen, and therefore the effect of full infiltration is achieved. After the cell 400 is sufficiently wetted, the unabsorbed electrolyte may be pumped away.

In order to facilitate the immersion of the battery cell 400 in a vacuum state and the subsequent formation of a high-purity nitrogen environment, preferably, the bottom of the first groove body 321 may be provided with a drain hole, and after sufficient immersion, vacuum may be provided to the closed first groove body 321 again to draw the electrolyte away from the drain hole. The first tank 321 is closed to form a vacuum and high purity nitrogen environment.

In addition, alternatively, the injection-chemical formation unit 320 may include a third tank for soaking the battery cell 400 after chemical formation to form a gel polymer electrolyte on the surface of the battery cell 400, and a curing device for curing the gel polymer electrolyte.

By forming and curing the gel polymer electrolyte on the surface of the battery cell 400, on one hand, the formed battery cell 400 can be replenished with liquid, and on the other hand, the gel polymer electrolyte can be cured to fix the electrolyte in the battery cell 400.

In order to realize the fluid replacement of the battery cell 400 and simultaneously form the gel polymer electrolyte, the gel electrolyte may contain the electrolyte, a monomer, a cross-linking agent and an initiator. Wherein, the percentage content and the type of the electrolyte, the monomer, the cross-linking agent and the initiator can be selected according to the requirement.

Specifically, the electrolyte may contain a lithium salt, a nonaqueous organic solvent, and an additive, as in the case of the impregnation.

The lithium salt is at least one selected from LiPF6, LiBF4, LiAsF6, LiClO4, LiBOB (lithium dioxalate borate), lidob (lithium difluorooxalate borate), LiCF3SO3, LiC4F9SO3, Li (CF3SO2)2N, and Li (C2F5SO2) 2N. The molar concentration of the lithium salt is 0.85 mol/L-1.3 mol/L.

The non-aqueous organic solvent includes at least one of carbonate, carboxylate, ether compound and aromatic compound.

The carbonate comprises cyclic carbonate and chain carbonate, and the mass ratio of the cyclic carbonate to the chain carbonate is 3: 1-1: 10.

The cyclic carbonate is at least one of ethylene carbonate EC, propylene carbonate PC and butylene carbonate, and the chain carbonate is at least one of dimethyl carbonate DMC, diethyl carbonate DEC, methyl ethyl carbonate EMC, dipropyl carbonate DPC, methyl propyl carbonate MPC, methyl isopropyl carbonate MiPC, methyl butyl carbonate BMC and dibutyl carbonate DBC.

The carboxylic acid ester includes unsubstituted carboxylic acid ester and halogenated carboxylic acid ester. The unsubstituted carboxylic acid ester is selected from: at least one of methyl formate MF, ethyl formate, n-propyl formate, isopropyl formate, methyl acetate MA, ethyl acetate, n-propyl acetate, isopropyl acetate, methyl propionate MP, ethyl propionate, methyl butyrate, ethyl butyrate, gamma-butyrolactone GBL, gamma-valerolactone, and caprolactone; the halogenated carboxylic acid ester is selected from: at least one of methyl fluorocarboxylate, ethyl fluorocarboxylate, methyl monofluoroacetate, methyl difluoroacetate, ethyl monofluoroacetate, ethyl difluoroacetate, ethyl trifluoroacetate, propyl fluorocarboxylate, methyl 3-fluoropropionate, methyl 3, 3-difluoropropionate, methyl 3,3, 3-trifluoropropionate, ethyl 3-fluoropropionate, ethyl 3, 3-difluoropropionate, and ethyl 3,3, 3-trifluoropropionate.

The ether compound comprises a non-substituted ether compound and a halogenated ether compound, wherein the non-substituted ether compound is selected from the following: one or more of dibutyl ether, dimethoxymethane, dimethoxyethane DME, diethoxymethane, diethoxyethane, tetrahydrofuran THF, and dimethyl tetrahydrofuran 2 Me-THG; the halogenated ether compound is selected from: monofluorodimethoxymethane, monofluorodimethoxyethane, monofluorodiethoxymethane, monofluorodiethoxyethane.

The aromatic compound is selected from: toluene, fluorobenzene, o-fluorotoluene, trifluorotoluene, 4-fluorotoluene, p-fluoromethoxybenzene, o-difluoromethoxybenzene, 1-fluoro-4-tert-butylbenzene, fluorobiphenyl.

The additive comprises at least one of vinylene carbonate VC, vinyl ethylene carbonate VEC, fluoroethylene carbonate FEC and 1, 3-propane sultone. The total weight of the additive accounts for 1-10 wt% of the total mass of the liquid electrolyte.

According to one embodiment of the invention, the gel electrolyte comprises 90-99.4 wt% of electrolyte, 0.5-3 wt% of monomer, 0.25-0.6 wt% of cross-linking agent and 0.1-1.5 wt% of initiator. Preferably, the gel electrolyte comprises 93-98 wt% of the electrolyte, 1-2 wt% of the monomer, 0.75-0.4 wt% of the cross-linking agent and 0.2-1 wt% of the initiator.

Wherein the monomer may be modified polyvinyl alcohol and its derivatives, the modified polyvinyl alcohol and its derivatives have an average molecular weight of 5 × 10⁴g/mol～15×10⁴g/mol (preferably 8X 10)⁴g/mol～12×10⁴g/mol); the modified polyvinyl alcohol and the derivative thereof are polyvinyl alcohol and the derivative thereof which are modified by a silane coupling agent containing double bonds. The derivative comprises at least one of polyvinyl acetal, polyvinyl butyral and polyvinyl formal.

The preparation method of the modified polyvinyl alcohol and the derivative thereof comprises the following steps: firstly, preparing a mixed solvent from water and ethanol according to the mass ratio of (1-9) to (9-1), heating while stirring, then adding polyvinyl alcohol or derivatives thereof accounting for 5-30% of the total mass of the mixed solvent, after completely dissolving, adding a silane coupling agent, separating out a generated oily polymer from the mixed solvent until an oil-free polymer is separated out, stopping adding the silane coupling agent, filtering out the oily polymer, and cleaning and purifying to obtain pure silane-modified polyvinyl alcohol or derivatives thereof.

Wherein the silane coupling agent comprises at least one of gamma- (methacryloyloxy) propyltrimethoxysilane, vinyltriisopropoxysilane, vinyldibutoxymethylsilane and vinyldimethylethoxysilane.

The crosslinking agent comprises at least one of diallyl carbonate, trimethylolpropane triacrylate, polyoxyethylene diacrylate, dipentaerythritol pentaacrylate, N' -methylenebisacrylamide, N-dimethylacrylamide, diacetone acrylamide, divinylbenzene, and crotonic acid.

The initiator includes at least one of Azobisisobutyronitrile (AIBN), azobisisoheptonitrile, azobisisovaleronitrile, azobiscyclohexylcarbonitrile, Benzoyl Peroxide (BPO), hydrogen peroxide, lauroyl peroxide, isobutyryl peroxide, and cumyl peroxide.

The third tank may be in a form similar to the first tank, and a third interface for sucking and/or breaking vacuum may be provided in the third tank, so that the third tank is repeatedly sucked and broken to obtain effects of sufficient fluid infusion and uniform gel polymer electrolyte formation on the surface of the battery cell 400.

In the present invention, the gel polymer electrolyte may be cured by various forms of curing means, and alternatively, the curing means may include an ultraviolet irradiation tunnel including a tunnel body and an ultraviolet irradiation assembly disposed within the tunnel body. In use, the uv irradiation assembly irradiates the gel polymer electrolyte to cure the gel polymer electrolyte as the cell 400 passes through the tunnel body.

The battery cell 400 passing through the ultraviolet irradiation tunnel may reach the encapsulation unit 380, and the battery cell 400 may be case-welded in the encapsulation unit 380.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. The technical scheme of the utility model in the technical conception scope, can be right carry out multiple simple variant. The present invention includes any combination of the specific features described herein in any suitable manner. In order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations. These simple variations and combinations should also be considered as disclosed in the present invention, all falling within the scope of protection of the present invention.

Claims

1. The lithium ion battery preparation system is characterized by comprising third equipment (300), wherein the third equipment (300) comprises a vacuum tunnel baking unit (310) for baking a battery cell, a liquid injection-formation unit (320) for injecting and forming the baked battery cell (400), and an encapsulation unit (380) for encapsulating the battery cell (400) into a shell.

2. The lithium ion battery preparation system according to claim 1, comprising a first apparatus (100), a second apparatus (200) and the third apparatus (300) which are arranged in sequence, wherein the first apparatus (100) is used for manufacturing a pole piece, and the second apparatus (200) is used for manufacturing the pole piece manufactured by the first apparatus (100) into the battery cell (400).

3. The lithium ion battery preparation system of claim 2, wherein the first equipment (100) comprises a pole piece preparation unit, and the pole piece preparation unit comprises a feeding device (110), a raw material classifier (120), a first iron removal device (130), a raw material buffer tank (140), a second iron removal device (150), a stirring device (160), a slurry storage tank (170) and a coating, rolling and slitting integrated machine (180) which are sequentially connected through a pipeline.

4. A lithium ion battery production system according to claim 3, characterized in that the first apparatus (100) comprises two said pole piece production units for producing a positive pole piece and a negative pole piece, respectively.

5. The lithium ion battery preparation system of claim 2, wherein the second apparatus (200) comprises a winding pre-pressing unit (210), a hot press molding unit (220), a cold press molding unit (230), a tab cutting unit (240) and a cell assembling unit (250) which are arranged in sequence.

6. The lithium ion battery preparation system of claim 5, wherein the winding prepressing unit (210), the hot press molding unit (220), the cold press molding unit (230), the tab cutting unit (240) and the cell assembling unit (250) are connected through a conveyer belt.

7. The lithium ion battery production system of claim 2, wherein the first apparatus (100), the second apparatus (200), and the third apparatus (300) are configured for continuous operation.

8. The lithium ion battery preparation system according to any one of claims 1 to 7, wherein the liquid injection-formation unit (320) comprises a first tank (321) having an open top, a first upper cover (322) capable of sealing the opening of the first tank (321), a second tank (323) having an open top, a second upper cover (324) capable of sealing the opening of the second tank (323), a tray (325) capable of being lifted in the first tank (321), and a formation device (326) capable of being lifted in the second tank (323), wherein the first tank (321) is provided with a first interface (3211) for sucking and/or breaking vacuum, and the second tank (323) is provided with a second interface (3231) for sucking and/or breaking vacuum.

9. The lithium ion battery preparation system of claim 8, wherein the injection-formation unit (320) comprises a third tank for soaking the cells (400) after formation to form a gel polymer electrolyte on the surfaces of the cells (400) and a curing device for curing the gel polymer electrolyte.

10. The lithium ion battery production system of any one of claims 1-7, characterized in that the third apparatus (300) comprises an electrolyte supply unit (330) for supplying electrolyte to the injection-formation unit, a first filtering device (340) disposed between the electrolyte supply unit (330) and the injection-formation unit, an electrolyte buffer tank (350), an electrolyte recovery unit (360) for recovering electrolyte of the injection-formation unit, and a second filtering device (370) disposed between the electrolyte recovery unit (360) and the electrolyte buffer tank (350), the electrolyte buffer tank (350) has a first inlet and a second inlet connected to the first filtering device (340) and the second filtering device (370), respectively, and an outlet connected to the injection-formation unit.