CN112713318A - Hot-pressing shaping method for winding core - Google Patents
Hot-pressing shaping method for winding core Download PDFInfo
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- CN112713318A CN112713318A CN202011606868.8A CN202011606868A CN112713318A CN 112713318 A CN112713318 A CN 112713318A CN 202011606868 A CN202011606868 A CN 202011606868A CN 112713318 A CN112713318 A CN 112713318A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
- B29C65/4805—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding characterised by the type of adhesives
- B29C65/481—Non-reactive adhesives, e.g. physically hardening adhesives
- B29C65/4815—Hot melt adhesives, e.g. thermoplastic adhesives
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
Abstract
The invention relates to the technical field of batteries, and discloses a hot-pressing shaping method for a winding core, which comprises the following steps: adhering the hot-melt adhesive tape to the bottom of the winding core to obtain a winding core assembly; wherein the hot melt adhesive tape at least comprises a hot melt adhesive layer; and then putting the roll core assembly into hot-pressing shaping equipment for hot pressing, so that the hot-melt adhesive layer is melted to bond the diaphragm layers at the bottom of the roll core. The hot-pressing shaping method of the winding core can not only prevent the pole piece or the diaphragm from being folded before the winding core enters the shell, but also solve the problem of battery drop test failure caused by the powder falling of the pole piece.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a hot-pressing shaping method for a winding core.
Background
The hot-pressing shaping is generally needed before the lithium ion battery winding core is packaged, and the existing winding core hot-pressing shaping method only can play a role in preventing the pole piece or the diaphragm from being folded before the winding core enters the shell. And the lithium ion battery after hot pressing and shaping is often failed in the battery drop test due to the powder falling of the pole piece when the battery drop test is carried out.
In order to reduce the powder falling phenomenon of the battery pole piece, people try many improvements, but only focus on the improvement of the pole piece, so that the preparation process of the pole piece is troublesome to modify, and the quality of the battery is seriously influenced. For example, increasing the binder content in the pole piece coating slurry results in a decrease in the content of the main material, which deteriorates the electrical properties of the battery, such as conductivity; for another example, increasing the content of the pole piece coating slurry leads to thickening and heaviness of the roll core, which is not beneficial to the light development of the battery; and so on.
Therefore, a method for preventing the electrode plate or the diaphragm from being folded before the winding core is inserted into the shell and reducing the powder falling phenomenon of the battery electrode plate is needed at present, so as to improve the quality of the lithium ion battery and promote the development of the lithium ion battery.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a hot-pressing shaping method of a winding core, which can not only prevent a pole piece from being folded or a diaphragm from being folded before the winding core enters a shell, but also solve the problem of battery drop test failure caused by powder falling of the pole piece.
The purpose of the invention is realized by the following technical scheme:
a hot-pressing shaping method for a winding core comprises the following steps:
adhering the hot-melt adhesive tape to the bottom of the winding core to obtain a winding core assembly; wherein the hot melt adhesive tape at least comprises a hot melt adhesive layer;
and then putting the roll core assembly into hot-pressing shaping equipment for hot pressing, so that the hot-melt adhesive layer is melted to bond the diaphragm layers at the bottom of the roll core.
In one embodiment, the hot-melt adhesive tape further comprises an anti-sticking isolation layer, and the anti-sticking isolation layer is stuck on one side surface of the hot-melt adhesive layer far away from the winding core.
In one embodiment, the function formula of the width of the hot melt adhesive layer is as follows: x is a-b; wherein x is the width of the hot melt adhesive layer, a is the width of the roll core, and b is the thickness of the roll core;
the functional formula of the length of the hot melt adhesive layer is as follows: y is b + c, wherein y is the length of the hot melt adhesive layer, and b is the thickness of the winding core; c is 6 mm to 16 mm.
In one embodiment, the thickness of the hot melt adhesive layer is 35 μm to 48 μm.
In one embodiment, the hot melt adhesive layer has a room temperature peel strength of 50N/cm to 150N/cm when cured.
In one embodiment, the bonding temperature of the hot melt adhesive layer is 45-80 ℃.
In one embodiment, the hot pressing operation is performed at a temperature of 45 ℃ to 80 ℃, under a pressure of 0.2MPa to 1.2MPa, and for a time of 5min to 20 min.
In one embodiment, the hot-pressing shaping equipment comprises a hot-pressing shell, a heating bottom plate, a front hot-pressing plate, a rear hot-pressing plate and a driving piece, wherein the heating bottom plate is arranged at the bottom of the hot-pressing shell, the front hot-pressing plate and the rear hot-pressing plate are respectively arranged in the hot-pressing shell, an accommodating groove is formed by enclosing the inner wall of the hot-pressing shell, the front hot-pressing plate and the rear hot-pressing plate together, and the driving piece is connected with the rear hot-pressing plate;
will the operation of putting into hot pressing plastic equipment and carrying out the hot pressing of core assembly specifically is: will roll up the core assembly and put into in the storage tank, through it is right to heat the bottom plate roll up the core assembly and heat, the rethread driving piece drive back hot pressing plywood is right roll up the core assembly and carry out the hot pressing.
In one embodiment, the hot pressing shaping device further includes a plurality of hot pressing movable plates, the plurality of hot pressing movable plates are respectively disposed in the accommodating groove at intervals to divide the accommodating groove into a plurality of separate grooves, and each of the separate grooves is respectively used for accommodating each of the winding core assemblies.
In one embodiment, the front hot-pressing board, the rear hot-pressing board, the heating bottom board and the plurality of hot-pressing movable boards are all provided with a buffering elastic layer on one side surface close to the winding core assembly.
Compared with the prior art, the invention has at least the following advantages:
the hot-pressing shaping method of the winding core is simple to operate, the original battery pole piece preparation process is not required to be changed, the diaphragm of the winding core is bonded with the pole piece through simple improvement of the existing winding core hot-pressing method, the bonding between the diaphragm layers at the bottom of the winding core can be realized, the pole piece can be prevented from being folded or folded before the winding core enters the shell, and meanwhile, the battery short circuit or micro short circuit caused by powder falling of the pole piece at the bottom of the winding core during the battery falling test can be prevented, so that the passing rate of the battery falling test is improved, and the quality of the battery is greatly improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a schematic structural diagram of a winding core assembly according to an embodiment of the present invention.
Fig. 2 is a schematic structural view of a hot melt adhesive tape according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a hot press forming apparatus according to an embodiment of the present invention.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.
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 invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In one embodiment, referring to fig. 1, a method for hot pressing and shaping a winding core includes the following steps: s110, adhering the hot-melt adhesive tape 120 to the bottom of the winding core 110 to obtain a winding core assembly 10; wherein the hot melt adhesive tape 120 at least comprises a hot melt adhesive layer 121; and S120, putting the winding core assembly 10 into hot-pressing shaping equipment for hot pressing, so that the diaphragm of the winding core 110 is bonded with the pole piece, and the hot melt adhesive layer 121 is melted to bond the diaphragm layers at the bottom of the winding core 110.
It should be noted that the hot melt adhesive layer 121 is an adhesive layer formed after the hot melt adhesive is cooled and solidified, and by using the characteristics of the hot melt adhesive and combining the above method steps, the diaphragm of the winding core 110 can be bonded to the pole piece, and the diaphragm layer at the bottom of the winding core 110 is bonded, so that not only can the pole piece be prevented from being folded or the diaphragm can be prevented from being folded before the winding core 110 enters the case, but also the battery short circuit or the micro short circuit caused by the powder falling of the pole piece at the bottom of the winding core 110 during the battery drop test can be prevented, and the passing rate.
Further, the hot melt adhesive tape 120 further includes an anti-adhesion isolation layer 122, and the anti-adhesion isolation layer 122 is adhered to a side of the hot melt adhesive layer 121 away from the winding core 110. Therefore, the hot melt adhesive layer 121 can be isolated by the anti-sticking isolation layer 122, and hot-pressing shaping equipment is prevented from being bonded after the hot melt adhesive layer 121 is melted; meanwhile, the guide and restraint function is also realized on the molten hot melt adhesive, and the expansion of the molten hot melt adhesive along the diaphragm layers is promoted, so that the diaphragm layers at the bottom of the winding core 110 are bonded.
For example, the anti-adhesion isolation layer 122 is made of insulating materials such AS PET, PBT, polyarylate, PI, PC, PP, PE, AS, ABS, PS, PC, PA, PPO, PPs, POM, POK, and LCP, and the thermal deformation temperature thereof should be at least higher than the bonding temperature of the hot melt adhesive layer 121.
In order to promote uniform entry of the molten hot melt adhesive between the separator layers at the bottom of the jellyroll 110, the function of the width of the hot melt adhesive layer 121 is preferably as follows: x is a-b; wherein x is the width of the hot melt adhesive layer 121, a is the width of the winding core 110, and b is the thickness of the winding core 110; the functional formula of the length of the hot melt adhesive layer 121 is as follows: y is b + c, where y is the length of the hot melt adhesive layer 121 and b is the thickness of the winding core 110; c is 6 mm to 16 mm. As another example, c is 6 millimeters, 10 millimeters, 12 millimeters, 14 millimeters, or 16 millimeters. Therefore, the molten hot melt adhesive can be promoted to uniformly enter the diaphragm layer at the bottom of the winding core 110, and the bonding effect between the diaphragm layers at the bottom of the winding core 110 is improved.
It is understood that the thickness of the hot melt adhesive layer 121 needs to be a certain thickness to exert its viscosity well, and if the thickness of the hot melt adhesive layer 121 is too large, the core 110 becomes thick and heavy, so the thickness of the hot melt adhesive layer 121 is preferably 35 μm to 48 μm. For example, the thickness of the hot melt adhesive layer 121 is 35 μm, 38 μm, 40 μm, 42 μm, 44 μm, 46 μm, or 48 μm.
In order to ensure that the bonding firmness between the separator layers at the bottom of the winding core 110 meets the requirement of a battery drop test, the room-temperature peel strength of the hot melt adhesive layer 121 during curing is preferably 50N/cm-150N/cm. For example, the hot melt adhesive layer 121 has a peel strength at room temperature of 50N/cm, 60N/cm, 70N/cm, 80N/cm, 90N/cm, 100N/cm, 110N/cm, 120N/cm, 130N/cm, 140N/cm, or 150N/cm when cured. So, can make hot melt adhesive layer 121 reach the degree of good bonding diaphragm to can guarantee that the bonding fastness between the diaphragm layer of rolling up core 110 bottom reaches the requirement of battery drop test.
It is understood that the high temperature may cause certain damage to the quality of the battery, and in order to reduce the damage of the hot pressing to the battery, the hot melt adhesive layer 121 with a lower melting point should be selected, and preferably, the bonding temperature of the hot melt adhesive layer 121 is 45 ℃ to 80 ℃. For example, the bonding temperature of the hot melt adhesive layer 121 is 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃. It should be noted that this temperature is not only the temperature at which the hot melt adhesive starts to soften and melt, but also the temperature at which the hot melt adhesive melts to such an extent that it bonds well to the membrane, i.e., the temperature at which the viscosity, fluid, viscosity, etc. of the hot melt adhesive are suitable for bonding the membrane. Therefore, the damage to the quality of the battery can be effectively reduced.
Therefore, the selection of the hot melt adhesive layer 121 is one of the keys. The hot melt adhesive layer 121 needs to have the following characteristics: (1) electrolyte corrosion resistance; (2) the room temperature peel strength during curing is 50N/cm-150N/cm; (3) the bonding temperature is 45-80 ℃.
In order to meet the above requirements, the hot melt adhesive tape 120 is a single-sided hot melt adhesive of Australian electronic materials Co.
For another example, the hot melt adhesive layer 121 is formed by curing a hot melt adhesive, and the hot melt adhesive comprises the following components in parts by weight: 15-25 parts of EVA 80015, 9005-15 parts of EVA, 5-7 parts of SBS, 15-25 parts of rosin glyceride, 4-6 parts of 2, 6-di-tert-butyl-p-cresol, 3-5 parts of dibutyl phthalate, 4-6 parts of polyethylene wax and 0-2 parts of glycidyl ether oxypropyltrimethoxysilane. The EVA800, the EVA900 and the SBS are used as main body resins, the rosin glyceride is used as tackifying resin, the 2, 6-di-tert-butyl-p-cresol is used as an antioxidant, the dibutyl phthalate is used as a plasticizer, the polyethylene wax is used as a viscosity regulator, and the glycidyl ether oxypropyl trimethoxysilane is used as a coupling agent.
Example 1, the hot melt adhesive layer 121 includes the following components in parts by weight: EVA 80015 parts, EVA 90015 parts, SBS 5 parts, rosin glyceride 15 parts, 2, 6-di-tert-butyl-p-cresol 6 parts, dibutyl phthalate 3 parts, polyethylene wax 6 parts and glycidyl ether oxypropyl trimethoxysilane 0 part.
Embodiment 2, the hot melt adhesive layer 121 includes the following components in parts by weight: EVA 80025 parts, EVA 9005 parts, SBS 7 parts, rosin glyceride 25 parts, 2, 6-di-tert-butyl-p-cresol 4 parts, dibutyl phthalate 5 parts, polyethylene wax 4 parts and glycidyl ether oxypropyl trimethoxysilane 2 parts.
Example 3, the hot melt adhesive layer 121 includes the following components in parts by weight: EVA 80020 parts, EVA 90010 parts, SBS 6 parts, rosin glyceride 20 parts, 2, 6-di-tert-butyl-p-cresol 5 parts, dibutyl phthalate 4 parts, polyethylene wax 5 parts and glycidyl ether oxypropyl trimethoxysilane 1 part.
The 3 embodiments adopt a conventional hot melt adhesive preparation process, and the hot melt adhesive is prepared through the synergistic effect of the components, and has (1) electrolyte corrosion resistance compared with the common hot melt adhesive; (2) the room temperature peel strength during curing is 50N/cm-150N/cm; (3) the bonding temperature is 45-80 ℃; (4) the wettability on the interfaces of the surface of a winding core, the surface of a pole piece, the surface of a diaphragm and the like is good; (5) has good flexibility.
3 comparative examples were designed, differing from example 3 only in the host resin. Wherein, the main resin of comparative example 1 is EVA 80024 parts plus EVA 90012 parts, compared with example 3, the hot melt adhesive of comparative example 1 has higher glass transition temperature and lower flexibility; the main resin of comparative example 2 is EVA 80036 parts, and the hot melt adhesive of comparative example 2 has higher viscosity and poor wettability on the interface compared to example 3; the main resin of comparative example 3 is EVA 90036 parts, and the hot melt adhesive of comparative example 3 has lower viscosity and poor adhesive force and adhesive strength compared to example 3.
It will be appreciated that the hot pressing operation is also intended to bond the separator layer at the bottom of the jellyroll 110, in addition to using a temperature and pressure to bond the separator of the jellyroll 110 to the pole pieces. Therefore, the temperature of the hot pressing operation should be the same as or slightly higher than the bonding temperature of the hot melt adhesive layer 121, for example, the temperature of the hot pressing operation is 45 to 80 ℃. For example, the temperature of the hot pressing operation is 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ or 80 ℃.
Further, the pressure of the hot pressing operation is 0.2MPa to 1.2MPa, and the time is 5min to 20 min. For example, the hot pressing is performed at a pressure of 0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa, 1.0MPa or 1.2MPa for a period of 5min, 7min, 9min, 11min, 13min, 15min, 17min or 20 min. Therefore, in a certain time, the diaphragm of the winding core 110 can be well bonded with the pole piece through hot pressing at a certain temperature and a certain pressure, so that the pole piece or the diaphragm is prevented from being folded before the winding core 110 enters the shell.
Further, the hot press shaping apparatus 20 includes a hot press housing 210, a heating bottom plate 220, a front hot press board 230, a rear hot press board 240, and a driving member 250, wherein the heating bottom plate 220 is disposed at the bottom of the hot press housing 210, the front hot press board 230 and the rear hot press board 240 are respectively disposed in the hot press housing, an inner wall of the hot press housing 210, the front hot press board 230, and the rear hot press board 240 together form a receiving groove, and the driving member 250 is connected to the rear hot press board 240. The driving member 250 is a driving device such as a cylinder, a motor, etc., and can automatically perform a linear reciprocating motion.
The operation of putting the roll core assembly 10 into the hot-pressing shaping device 20 for hot pressing is specifically as follows: will roll up core assembly 10 and put into in the storage tank, through heating bottom plate 220 is right roll up core assembly 10 and heat, the rethread driving piece 250 drive back hot pressing plywood 240 is right roll up core assembly 10 and carry out the hot pressing.
So, through heating bottom plate 220 makes hot pressing shell 210's inside temperature heaies up to required hot pressing temperature, and hot pressing plywood 240 moves to the direction that is close to preceding hot pressing plywood 230 after the rethread driving piece 250 drive, carries out the hot pressing to rolling up core assembly 10, enables to roll up the diaphragm and the pole piece of core assembly 10 and well bonds, also enables to roll up the diaphragm layer of core assembly 10 bottom simultaneously and bonds well.
Further, the hot press shaping apparatus 20 further includes a plurality of hot press movable plates 260, for example, 3 to 30 hot press movable plates 260. The plurality of hot pressing movable plates 260 are respectively disposed in the accommodating groove at intervals so as to partition the accommodating groove into a plurality of separate grooves 211, and each separate groove 211 is respectively used for accommodating each winding core assembly 10. So, can hold a plurality of book core assemblies 10 respectively through a plurality of branch put grooves 211, at the hot pressing in-process, back hot pressing plywood 240 promotes the hot pressing fly leaf 260 of rear end and gos forward, and the hot pressing fly leaf 260 of rear end promotes the hot pressing fly leaf 260 of front end in proper order and gos forward, can once accomplish the hot pressing to a plurality of book core assemblies 10, improves hot pressing efficiency.
Further, the heating bottom plate 220, the front hot pressing plate 230, the rear hot pressing plate 240, and the plurality of hot pressing plates 260 are provided with a buffering elastic layer on a side surface thereof close to the winding core assembly 10. Thus, the deformation of the roll core assembly 10 in the hot pressing process is avoided through the buffering performance of the buffering elastic layer. For example, the buffering elastic layer is made of elastic material such as silicone rubber, etc., and the thermal deformation temperature thereof should be at least higher than the bonding temperature of the hot melt adhesive layer 121.
The battery drop test is carried out on 100 common lithium ion batteries and 100 lithium ion batteries prepared by adopting the winding core hot-pressing shaping method according to enterprise standards, the enterprise standards are more strict than the test requirements of the current national standard GB31241-2014 in the industry, and the specific test method is as follows: after the lithium ion battery is fully charged, the roller falling is carried out in a steel plate roller machine according to the falling height of 1m, the falling frequency is ten times per minute, and 100 experiments are carried out totally. The voltage change of the lithium ion battery after the experiment is required to be less than 0.1v, the internal resistance change is less than 50m omega, and the phenomena of liquid leakage, smoke, fire and explosion are avoided. The experimental results are as follows: the qualification rate of the common lithium ion battery is 50%, and the qualification rate of the lithium ion battery prepared by the winding core hot-pressing shaping method can reach more than 95%.
Compared with the prior art, the invention has at least the following advantages:
the hot-pressing shaping method of the winding core 110 is simple to operate, the original battery pole piece preparation process is not required to be changed, the existing hot-pressing method of the winding core 110 is simply improved, when the diaphragm and the pole piece of the winding core 110 are bonded, the diaphragm layer at the bottom of the winding core 110 can also be bonded, the pole piece can be prevented from being folded or folded before the winding core 110 enters the shell, and meanwhile, the battery short circuit or the micro short circuit caused by the powder falling of the pole piece at the bottom of the winding core 110 during the battery falling test can also be prevented, so that the passing rate of the battery falling test is improved, and the quality of the battery is greatly.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A hot-pressing shaping method for a winding core is characterized by comprising the following steps:
adhering the hot-melt adhesive tape to the bottom of the winding core to obtain a winding core assembly; wherein the hot melt adhesive tape at least comprises a hot melt adhesive layer;
and then putting the roll core assembly into hot-pressing shaping equipment for hot pressing, so that the hot-melt adhesive layer is melted to bond the diaphragm layers at the bottom of the roll core.
2. The method for hot-pressing and shaping the winding core according to claim 1, wherein the hot-melt adhesive tape further comprises an anti-adhesion isolation layer, and the anti-adhesion isolation layer is adhered to one side surface of the hot-melt adhesive layer, which is far away from the winding core.
3. The core hot-pressing reshaping method of claim 1, wherein a function formula of the width of the hot melt adhesive layer is as follows: x is a-b; wherein x is the width of the hot melt adhesive layer, a is the width of the roll core, and b is the thickness of the roll core;
the functional formula of the length of the hot melt adhesive layer is as follows: y is b + c, wherein y is the length of the hot melt adhesive layer, and b is the thickness of the winding core; c is 6 mm to 16 mm.
4. The hot-pressing reshaping method for the winding core according to claim 1, wherein the thickness of the hot-melt adhesive layer is 35-48 μm.
5. The hot-pressing reshaping method for the winding core according to claim 1, wherein the room-temperature peel strength of the hot melt adhesive layer during curing is 50N/cm-150N/cm.
6. The hot-pressing reshaping method for the winding core according to claim 1, wherein the bonding temperature of the hot-melt adhesive layer is 45-80 ℃.
7. The hot-pressing reshaping method for the winding core according to claim 6, wherein the hot-pressing operation is performed at a temperature of 45-80 ℃, under a pressure of 0.2-1.2 MPa, and for a time of 5-20 min.
8. The hot-pressing shaping method for the winding core according to claim 1, wherein the hot-pressing shaping equipment comprises a hot-pressing shell, a heating bottom plate, a front hot-pressing plate, a rear hot-pressing plate and a driving piece, the heating bottom plate is arranged at the bottom of the hot-pressing shell, the front hot-pressing plate and the rear hot-pressing plate are respectively arranged in the hot-pressing shell, an accommodating groove is formed by enclosing the inner wall of the hot-pressing shell, the front hot-pressing plate and the rear hot-pressing plate together, and the driving piece is connected with the rear hot-pressing plate;
will the operation of putting into hot pressing plastic equipment and carrying out the hot pressing of core assembly specifically is: will roll up the core assembly and put into in the storage tank, through it is right to heat the bottom plate roll up the core assembly and heat, the rethread driving piece drive back hot pressing plywood is right roll up the core assembly and carry out the hot pressing.
9. The core hot-pressing shaping method according to claim 8, wherein the hot-pressing shaping device further comprises a plurality of hot-pressing movable plates, the hot-pressing movable plates are respectively disposed in the accommodating groove at intervals to divide the accommodating groove into a plurality of separate grooves, and each separate groove is respectively used for accommodating each core assembly.
10. The method for hot press shaping of the winding core according to claim 9, wherein the front hot press plate, the rear hot press plate, the heating base plate and the hot press plates are provided with a buffering elastic layer on one side surface close to the winding core assembly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011606868.8A CN112713318A (en) | 2020-12-28 | 2020-12-28 | Hot-pressing shaping method for winding core |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011606868.8A CN112713318A (en) | 2020-12-28 | 2020-12-28 | Hot-pressing shaping method for winding core |
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| CN112713318A true CN112713318A (en) | 2021-04-27 |
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| CN (1) | CN112713318A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204407402U (en) * | 2014-12-30 | 2015-06-17 | 东莞市澳中电子材料有限公司 | A kind of lithium ion battery of architecture advances |
| CN105390627A (en) * | 2015-10-16 | 2016-03-09 | 广东烛光新能源科技有限公司 | Electrochemical cell and preparation method thereof |
| CN209418699U (en) * | 2019-03-08 | 2019-09-20 | 易佰特新能源科技有限公司 | A kind of soft bag lithium ionic cell single side Hot melt adhesive plaster plastic structure |
| CN209515904U (en) * | 2019-01-30 | 2019-10-18 | 合肥国轩高科动力能源有限公司 | Device for hot-pressing and shaping of winding core |
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2020
- 2020-12-28 CN CN202011606868.8A patent/CN112713318A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204407402U (en) * | 2014-12-30 | 2015-06-17 | 东莞市澳中电子材料有限公司 | A kind of lithium ion battery of architecture advances |
| CN105390627A (en) * | 2015-10-16 | 2016-03-09 | 广东烛光新能源科技有限公司 | Electrochemical cell and preparation method thereof |
| CN209515904U (en) * | 2019-01-30 | 2019-10-18 | 合肥国轩高科动力能源有限公司 | Device for hot-pressing and shaping of winding core |
| CN209418699U (en) * | 2019-03-08 | 2019-09-20 | 易佰特新能源科技有限公司 | A kind of soft bag lithium ionic cell single side Hot melt adhesive plaster plastic structure |
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Application publication date: 20210427 |