CN111463497A - Local deformation improvement method of high-energy-density flexible package ion battery and battery - Google Patents
Local deformation improvement method of high-energy-density flexible package ion battery and battery Download PDFInfo
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- CN111463497A CN111463497A CN202010307866.2A CN202010307866A CN111463497A CN 111463497 A CN111463497 A CN 111463497A CN 202010307866 A CN202010307866 A CN 202010307866A CN 111463497 A CN111463497 A CN 111463497A
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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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- 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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- 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
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Abstract
The invention provides a local deformation improving method of a high-energy density flexible package ion battery and the battery, comprising the following steps: setting protection glue parameters and pasting protection glue on the positive plate and the negative plate according to the protection glue parameters; preparing a winding core by using the positive plate and the negative plate which are stuck with the protective adhesive, and preparing the winding core into a battery cell according to a battery cell preparation flow; carrying out formation operation on the battery cell by using a high-temperature pressurization formation cabinet, acquiring the thicknesses of multiple positions of the battery cell in the formation operation process, and adjusting the post-formation surface pressure of the battery cell according to the thicknesses of the multiple positions of the battery cell; calculating the coefficient of free electrolyte of the finished battery cell, setting vacuumizing time according to the coefficient of free electrolyte, vacuumizing the finished battery cell according to the vacuumizing time, and preparing the lithium ion battery by using the vacuumized battery cell. The invention can obviously reduce the local deformation of the battery and enhance the service performance of the battery.
Description
Technical Field
The invention belongs to the technical field of lithium batteries, and particularly relates to a local deformation improvement method of a high-energy-density flexible package ion battery and the battery.
Background
With the development of thinning and intellectualization of mobile phones, the requirement on energy density of mobile phone batteries is higher and higher, and in order to improve the energy density of the batteries, various large battery core manufacturers increasingly use coating diaphragms with base film thicknesses of 4um and 5um, which are coated with polymer materials such as polyvinylidene fluoride or acrylic and the like on the surfaces, use graphite materials with compaction density of 1.9, lithium cobalt oxide materials with compaction density of 4.2 or more than 4.4, use ultrathin aluminum plastic films with thicknesses of 65um and 76um, and meanwhile, the coating surface densities of positive and negative pole pieces are higher and higher. With the use of these materials and high coating areal density processes, new problems are also evident when the energy density of soft-packed lithium ion batteries is increased over and over compared to conventional soft-packed lithium ion batteries. In the circulation process, the positions of the middle of the battery pole lug, the two sides of the pole lug, the bottom angle and the like are easy to generate local deformation, namely, the thickness expansion is obvious in other positions. The reason is that firstly, the polymerization degree of the glue on the diaphragm is different from that of the positive pole piece after high-temperature pressurization formation, so that the serious polarization phenomenon occurs inside the battery. Secondly, the high compaction and high coating surface density of the anode and the cathode can cause the soaking speed of electrolyte on the pole piece to be slow in the standing process after liquid injection, an SEI film formed after the battery which is not fully soaked is unstable, and lithium is easy to be separated in the circulating process to cause the deformation of a lithium separation position and the fast attenuation of the battery capacity. And thirdly, under the conditions of high compaction and high coating amount, because the porosity of the pole piece is low and the liquid absorption speed is low, part of free electrolyte which is not absorbed into the pole piece is inevitably reserved in the battery after secondary sealing. If the amount of free electrolyte in the battery is large, the phenomenon that the free electrolyte which is more remained at the upper part and the lower part of the shell is sucked by the siphonage phenomenon of the diaphragm, so that a diaphragm polymerization layer which is polymerized and adhered with the positive electrode is foamed, the upper part and the bottom part of the battery core are bulged and deformed in the circulating process can occur, and the lithium precipitation can occur at the deformed position, so that the circulating capacity retention rate of the battery is sharply reduced.
Most of the existing mobile phones adopt non-detachable built-in batteries, once the local position of the battery is deformed, the battery is slightly pushed against the screen, white spots appear at certain positions when the screen is touched, and lithium precipitation occurs at the deformed position when the screen is serious, so that the probability of ignition and explosion of the battery in the use process is increased, and most of the accidents are reported in recent years. Therefore, the problem of local position deformation of the high-energy density flexible package lithium ion battery in the using process is also concerned by more and more battery manufacturers.
Disclosure of Invention
In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for improving local deformation of a high energy density flexible package ion battery and a battery, so as to solve the above-mentioned technical problems.
In a first aspect, the present invention provides a method for improving local deformation of a high energy density flexible package ion battery, comprising:
setting protection glue parameters and pasting protection glue on the positive plate and the negative plate according to the protection glue parameters;
preparing a winding core by using the positive plate and the negative plate which are stuck with the protective adhesive, and preparing the winding core into a battery cell according to a battery cell preparation flow;
whether the battery is fully soaked or not is judged by detecting the stability of the soaking voltage of the battery after liquid injection:
if so, carrying out formation operation on the battery cell by using a high-temperature pressurization formation cabinet, acquiring the thicknesses of multiple positions of the battery cell in the formation operation process, and adjusting the post-formation surface pressure of the battery cell according to the thicknesses of the multiple positions of the battery cell;
calculating the coefficient of free electrolyte of the finished battery cell, setting vacuumizing time according to the coefficient of free electrolyte, vacuumizing the finished battery cell according to the vacuumizing time, and preparing the lithium ion battery by using the vacuumized battery cell.
Further, setting the protection glue parameter includes:
calculating the width of the positive pole tab protection glue according to the position of the positive pole tab, wherein the width of the positive pole tab protection glue is equal to the sum of the size of the positive pole folding head and 2 mm;
calculating the width of the positive coating line protective adhesive according to the position of the positive pole lug, wherein the width of the positive coating line protective adhesive is the sum of the size of the positive pole lug metal belt from the positive pole folding line and 2 mm;
calculating the width of a negative pole tab protection glue according to the position of a negative pole tab, wherein the width of the negative pole tab protection glue is the sum of the size of a negative pole folding head and 2 mm;
and calculating the width of the negative pole piece balance glue according to the first folding width of the negative pole winding, wherein the width of the negative pole piece balance glue is the difference between the first folding width of the negative pole winding and 2 mm.
Further, the method further comprises:
the width of the positive electrode tab protection adhesive is 6-70mm, the thickness is 0.06-0.1mm, and the material is polypropylene insulating adhesive tape; when pasting the adhesive, the adhesive is overlapped with the protective adhesive of the positive coating line by 0.5-1mm, the upper end of the adhesive is overlapped with the lower edge of the positive pole tab adhesive by 0-0.5mm, and the lower end of the adhesive exceeds the lower edge of the pole piece by 0-0.5 mm;
the width of the protective adhesive of the positive coating line is 4-72mm, the thickness is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, and the two ends of the protective adhesive exceed the edges of the pole pieces by 0-0.5 mm;
the width of the negative pole tab protection glue is 6-70mm, the thickness is 0.01-0.06mm, the material is polypropylene insulation adhesive tape, the upper end overlaps 0-0.5mm with the lower edge of the negative pole tab glue when gluing, and the lower end exceeds 0-0.5mm of the lower edge of the pole piece;
the width of the negative pole piece balance adhesive tape is 18-138mm, the thickness is 0.01-0.06mm, the material is polyethylene terephthalate insulating adhesive tape, and the thickness is 0.035-0.06 mm; 0-0.5mm from the edge of the negative pole piece, 1-2mm from the negative pole material area, 1-2mm from the negative pole folding line and 1-2mm from the lower edge of the negative pole lug metal belt.
Further, the core is rolled up in positive plate and negative plate preparation that utilizes to paste and have the protection to glue includes:
winding the positive plate and the negative plate stuck with the protective adhesive into a winding core according to the sequence of the diaphragm, the negative electrode, the diaphragm and the positive electrode;
and finally, the winding core is arranged and folded into an aluminum foil, the ending position is arranged at the central position of the distance between the anode and the cathode tabs, and a winding core with the width of 6mm is used for stopping the adhesive tape for fixing.
Furthermore, the thickness of the stop adhesive tape of the winding core is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, the distance from the stop adhesive tape to the upper edge of the diaphragm is 0-2mm, and the distance from the stop adhesive tape to the lower edge of the diaphragm is 0-2 mm; the thickness of the adhesive tape at the top of the winding core is 0.01-0.06mm, the material is a polypropylene insulating adhesive tape, the distance from the upper edge of the diaphragm is 0-2mm, the length of the adhesive tape is 10-30mm, and the width of the adhesive tape is 4-70 mm.
Further, will according to electric core preparation flow roll up core preparation for electric core, include:
and preparing the winding core into the battery cell according to the preparation processes of pressing the battery cell, measuring short circuit, pasting winding core top glue, detecting the center distance of the tabs, packaging, baking the battery cell and injecting liquid.
Further, during the formation operation, the method further comprises:
setting detection interval time from liquid injection to formation;
measuring the wetting voltage of the battery cell according to the interval time;
judging whether the absolute value of the difference value between the infiltration voltage measured at the current time and the infiltration voltage measured at the previous time is not more than a preset stability threshold value:
if so, judging that the current cell soakage voltage change is stable and can be formed;
if not, judging that the current battery core is not soaked by the electrolyte, and continuously placing and soaking the battery core to wait for the next soaking voltage measurement.
Further, the acquiring thicknesses of the plurality of positions of the battery cell in the formation operation process, and adjusting post-formation surface pressure of the battery cell according to the thicknesses of the plurality of positions of the battery cell include:
symmetrically arranging a first measuring point, a second measuring point, a third measuring point, a fourth measuring point, a fifth measuring point and a sixth measuring point on the edge of the battery cell on the surface of the battery cell; the first measurement point and the second measurement point are two end points of the upper edge of the battery cell; the third measuring point and the fourth measuring point are two end points of the lower edge of the battery core; the fifth measuring point and the sixth measuring point are two end points of the central axis of the battery cell;
calculating a first thickness difference between the first measuring point and the second measuring point, a second thickness difference between the third measuring point and the fourth measuring point, and a third thickness difference between the fifth measuring point and the sixth measuring point;
judging whether the first thickness difference, the second thickness difference and the third thickness difference do not exceed a preset thickness threshold value:
if yes, the post-formation surface pressure does not need to be adjusted;
if not, increasing the formation surface pressure to the measurement point area corresponding to the thickness difference exceeding the preset thickness threshold, wherein the formation surface pressure increasing method comprises the following steps: when the thickness difference is 0.05-1mm, the formation surface pressure needs to be increased by 0.5kg/cm 2; when the thickness difference exceeds 1mm, the formation surface pressure is increased by 2kg/cm2, and the formation surface pressure range is 7-17kg/cm 2.
Further, the calculating the free electrolyte coefficient of the completed battery cell and setting the vacuum-pumping time according to the free electrolyte coefficient includes:
the coefficient of the free electrolyte is the difference obtained by subtracting the quotient of the weight of the shell body after the winding core of the battery is removed and the weight of the electrolyte on the inner wall of the shell body after the electrolyte is wiped off from the design capacity of the battery;
judging whether the coefficient of the free electrolyte is within 0.02-0.06 g/Ah:
if so, setting the vacuumizing time to be 2-3s of the conventional time;
if not, the vacuumizing time is adjusted by a step pitch of 0.5s on the basis of the conventional time, the vacuumizing time is increased when the coefficient of the free electrolyte exceeds 0.06g/Ah, and the vacuumizing time is reduced when the coefficient of the free electrolyte is lower than 0.02 g/Ah.
In a second aspect, the invention provides a high energy density flexible package ion battery prepared by the method provided in the first aspect.
The beneficial effect of the invention is that,
according to the method for improving the local deformation of the high-energy-density flexible package ion battery and the battery, the width of the tab protection glue is attached to the edges of the aluminum foil and the copper foil, so that the thickness of a hollow foil area which is not coated with active substances on two sides of the tab can be increased, the end adhesive tape of the winding core is lengthened to the edge of the diaphragm, a top glue is attached to the back surface of the winding core, the thickness between the two tabs on the winding core can be increased, the thickness gradient formed between the two tabs is reduced, when the battery is formed by a high-temperature clamp, the pressure on the diaphragm in the middle area of the two tabs can be increased, the pressure difference between the position and the tabs is reduced, and the problem that the diaphragm in the middle position of the tab is not polymerized with the positive. The adhesive tape is pasted on the empty foil area which is not coated with the active substance on the outer side of the electrode lug, so that the thickness of the outer side area of the electrode lug can be increased, the pressure difference between the position and the electrode lug is reduced, and the problem that a diaphragm and a positive electrode at the outer side position of the electrode lug are not polymerized due to large thickness gradient is solved. Therefore, the problem of deformation of the middle position and the two sides of the battery tab in the circulating process is solved.
According to the lithium ion battery, the negative electrode balance adhesive tape is pasted, so that the thickness of a tab region which is not welded at the lower end of the pole piece can be increased, the thickness gradient formed between the position and the two tabs is reduced, the pressure on a diaphragm at the tab position which is not welded at the lower end of the pole piece can be increased when the battery is formed by a high-temperature clamp, the pressure difference between the position and the tabs is reduced, and the problem that the tab region which is not welded at the lower end of the pole piece is not polymerized with the positive electrode due to large thickness gradient is solved. Therefore, the problem of deformation of the bottom angle of the battery in the circulating process is solved.
The lithium ion battery provided by the invention has the advantages that the soaking voltage of the battery at high temperature for different times after liquid injection is measured, and the battery formation is carried out after the soaking voltage curve is stable, so that the problems of unstable SEI (solid electrolyte interphase) film caused by insufficient physical soaking of electrolyte with poor liquid absorption of a pole piece and rapid battery deformation and capacity attenuation caused by lithium separation in the circulation process are solved.
According to the lithium ion battery, the thickness of 6 positions of the battery after the pre-formation is measured, and the formal formation surface pressure is determined according to the thickness difference of the pre-formation battery, so that the proper surface pressure can be determined before the formal formation of a large number of batteries, and on one hand, a large number of defective products caused by poor polymerization of the diaphragm and the anode due to the improper surface pressure can be avoided, and on the other hand, the proper surface pressure ensures that the diaphragm and the anode have good polymerization effect, so that the reaction consistency during the formation of the battery is improved, and the cycle performance is more stable.
According to the lithium ion battery, the amount of free electrolyte in the shell after the two-seal of the battery is measured, and the vacuumizing time of the two-seal equipment is determined according to the method for controlling the coefficient of the free electrolyte, so that the phenomena that a diaphragm polymerization layer which is polymerized and adhered with a positive electrode is foamed and deformed at the upper part and the bottom part of a battery cell in the circulation process due to the fact that more free electrolyte remained at the upper part and the lower part of the shell is sucked by the diaphragm siphonage are reduced.
In addition, the invention has reliable design principle, simple structure and very wide application prospect.
Drawings
In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is a schematic front view of a positive electrode sheet according to example 1 of the present invention when it is unrolled;
FIG. 2 is a schematic reverse view of the positive electrode sheet of example 1 according to the present invention when it is expanded;
FIG. 3 is a schematic view of a folded end of a positive plate in the embodiment 1 of the present invention;
fig. 4 is a schematic front view of the cathode sheet in example 2 of the present invention when it is unfolded;
FIG. 5 is a schematic reverse view of the cathode sheet of example 2 according to the present invention when it is unfolded;
fig. 6 is a schematic view of a folded end of a negative electrode sheet in example 2 of the present invention when the negative electrode sheet is unfolded;
FIG. 7 is a schematic front view of a roll core after being glued according to embodiment 3 of the present invention;
FIG. 8 is a schematic view of the back side of a roll core after being glued according to embodiment 3 of the present invention;
FIG. 9 is a graph showing the soaking voltage after the battery of example 4 of the present invention is injected;
FIG. 10 is a schematic diagram of a thickness measurement position after formation of a battery according to example 4 of the present invention;
11, a positive electrode tab; 12. protecting glue for a positive electrode tab; 13. the positive coating line 1 is coated with protective glue; 14. the positive coating line 2 is coated with protective glue; 15. the positive coating line 3 is coated with protective glue; 16. the positive coating line 4 is coated with protective glue; 17 a positive electrode tab tape; 18. a positive electrode material area; 21 a negative electrode tab; 22. protecting glue for a negative pole tab; 23. a negative electrode balance adhesive tape; 24. a negative electrode tab tape; 25. a negative electrode material area; 31. a winding core; 32. winding the core to terminate the tape; 33. and (5) winding core top glue.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a local deformation improving method of a high-energy-density flexible package ion battery, which comprises the following steps:
s1, setting protection glue parameters and pasting protection glue on a positive plate and a negative plate according to the protection glue parameters;
the method specifically comprises the following steps: the width of the protective adhesive of the positive pole tab 11 is calculated according to the position of the positive pole tab 11, and the calculation method is as follows:
the width of the protective glue of the positive electrode tab 11 is equal to the size of the positive electrode folding head plus 2 mm; the width of the protective glue of the positive pole tab 11 is 6-70mm, the thickness is 0.06-0.1mm, and the material is polypropylene insulating tape. When in gluing, the glue is overlapped with the protective glue of the coating line 1 by 0.5-1mm, the upper end of the glue is overlapped with the lower edge of the positive pole tab 11 by 0-0.5mm, and the lower end of the glue exceeds the lower edge of the pole piece by 0-0.5 mm.
The width of the protective adhesive of the positive coating line 1 is calculated according to the position of the positive electrode tab 11, and the calculation method is as follows: the width of the protective glue of the positive electrode coating line 1 is equal to the size of the positive electrode tab 11 metal belt from the positive electrode folding line plus 2 mm; the width of the protective adhesive of the positive coating line 1 is 4-72mm, the thickness is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, and the two ends of the protective adhesive tape exceed the edges of the pole pieces by 0-0.5 mm.
And (3) calculating the width of the protective adhesive of the positive coating line 2 according to the position of the negative pole tab 21 by the following calculation method: the width of the protective glue on the positive electrode coating line 2 is equal to the distance between the metal belt of the negative electrode tab 21 and the negative electrode head folding line +2 mm; the width of the protective adhesive of the positive coating line 2 is 4-72mm, the thickness is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, and the two ends of the protective adhesive tape exceed the edges of the pole pieces by 0-0.5 mm.
And calculating the width of the protective adhesive of the negative pole tab 21 according to the position of the negative pole tab 21 as follows: the width of the protection glue of the negative electrode tab 21 is equal to the size of the negative electrode folding head plus 2 mm; the width of the protective glue of the negative pole tab 21 is 6-70mm, the thickness is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, the upper end is overlapped with the lower edge of the glue of the negative pole tab 21 by 0-0.5mm during gluing, and the lower end exceeds the lower edge of the pole piece by 0-0.5 mm.
Calculating the width of the balance glue of the negative pole piece according to the first folding width of the negative pole winding, wherein the calculation method comprises the following steps: the width of the negative pole piece balance glue is equal to the first folding width of negative pole winding-2 mm; the width of the negative pole piece balance adhesive tape is 18-138mm, the thickness is 0.01-0.06mm, the material is polyethylene terephthalate insulating adhesive tape, and the thickness is 0.035-0.06 mm. 0-0.5mm from the edge of the negative pole piece, 1-2mm from the negative pole material area, 1-2mm from the negative pole folding line and 1-2mm from the lower edge of the metal belt of the negative pole tab 21.
S2, preparing a winding core 31 by using the positive plate and the negative plate which are pasted with the protective glue, and preparing the winding core 31 into an electric core according to an electric core preparation flow, which specifically comprises the following steps:
except that the width of the adhesive tape in the step S1 needs to be calculated according to a formula, the width of the protective adhesive of other coating lines of the positive electrode is obtained by a method which is commonly used in the industry, and the pole piece pasted with the adhesive tape is wound into a winding core 31 according to the sequence of a diaphragm, a negative electrode, the diaphragm and the positive electrode. The last folding of the winding core 31 is aluminum foil, the ending position is at the center position of the distance between the anode and the cathode tabs 21, and the winding core 31 with the width of 6mm is used for stopping the adhesive tape for fixing. The thickness of the stop adhesive tape of the winding core 31 is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, the distance from the upper edge of the diaphragm is 0-2mm, and the distance from the lower edge of the diaphragm is 0-2 mm. The thickness of the adhesive tape on the top of the winding core 31 is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, the distance from the upper edge of the diaphragm is 0-2mm, the length of the adhesive tape is 10-30mm, and the width of the adhesive tape is 4-70 mm.
The manufactured core 31 is pressed, short circuit is measured, the top glue of the core 31 is pasted, the center distance of the tabs is detected, the battery cell is packaged, the battery cell is baked, and liquid is injected, so that the post-injection battery cell is obtained.
S3, judging whether the battery is fully soaked by detecting the stability of the battery soaking voltage after liquid injection: if yes, the electric core is subjected to formation operation by using a high-temperature pressurization formation cabinet, the thicknesses of multiple positions of the electric core are collected in the formation operation process, and the post-formation surface pressure of the electric core is regulated according to the thicknesses of the multiple positions of the electric core, so that the method specifically comprises the following steps:
after liquid injection, the battery core is placed in a high-temperature room, the battery voltage, namely the soaking voltage, is measured every 2 hours, the battery with the stable soaking voltage change curve and meeting the stability requirement is subjected to pre-formation operation on a high-temperature pressurization forming cabinet.
And measuring the thickness of 6 positions on the surface of the battery, calculating the thickness difference, and determining the formation surface pressure according to the thickness difference. The positions 1 and 2 are two end points of the upper edge of the battery cell, the positions 3 and 4 are two end points of the lower edge of the battery cell, and the positions 5 and 6 are two end points of the central axis of the battery cell. The thickness difference between the position 1 and the position 2, the thickness difference between the position 3 and the position 4, and the thickness difference between the position 5 and the position 6 are less than or equal to 0.05mm, the formation surface pressure is not required to be adjusted, batch formation operation can be carried out according to the pre-formation surface pressure in formal formation, when the thickness difference is 0.05-1mm, the surface pressure in formal formation needs to be increased by 0.5kg/cm2, when the thickness difference exceeds 1mm, the surface pressure needs to be increased by 2kg/cm2, and the formation surface pressure range is 7-17kg/cm 2.
S4, calculating the coefficient of free electrolyte of the finished battery cell, setting vacuumizing time according to the coefficient of free electrolyte, vacuumizing the finished battery cell according to the vacuumizing time, and preparing the lithium ion battery by using the vacuumized battery cell, wherein the method specifically comprises the following steps:
and (4) determining the secondary sealing vacuumizing time according to the coefficient of free electrolyte before the formal secondary sealing of the battery cell after the formal formation is finished. The free electrolyte coefficient calculation formula is as follows:
coefficient of free electrolyte (weight of case after removal of winding core 31 from battery-weight after wiping off electrolyte on inner wall of case/design capacity of battery
If the calculated coefficient of the free electrolyte is within the range of 0.02-0.06g/Ah, setting the vacuumizing time to be 2-3s of the conventional time; if the free electrolyte coefficient is not within the range of 0.02-0.06g/Ah, the vacuumizing time is adjusted by a step pitch of 0.5s on the basis of the conventional time, the vacuumizing time is increased when the free electrolyte coefficient exceeds 0.06g/Ah, and the vacuumizing time is reduced when the free electrolyte coefficient is lower than 0.02 g/Ah.
In order to facilitate understanding of the present invention, the method for improving local deformation of a high energy density flexible package ion battery provided by the present invention is further described below by using the principle of the method for improving local deformation of a high energy density flexible package ion battery of the present invention and combining the processes of improving local deformation of a high energy density flexible package ion battery in the embodiments.
Example 1
Referring to fig. 1-3, the method for improving local deformation of a high energy density flexible package ion battery provided in this embodiment adopts a different positive electrode plate compared to the conventional method.
A positive pole piece comprises a positive pole tab 11, positive pole tab protective glue 12, positive pole coating line 1 protective glue 13, positive pole coating line 2 protective glue 14, positive pole coating line 3 protective glue 15, positive pole coating line 4 protective glue 16, a positive pole piece belt 17 and a positive pole material area 18.
Anodal pole piece, anodal book head size is 16mm, book head back anodal strap is 5mm apart from book head line size, anodal utmost point ear 11 width is 6mm, anodal utmost point ear protection 12 glues the width and is 18mm, anodal coating line 1 protection is glued 13 width and is 7mm, anodal coating line 2 protection is glued width 14 and is 19mm, anodal coating line 3 protection is glued 15 and is glued 16 widths with coating line 4 protection and is 6mm, the protection is glued the thickness and is 16 um.
Example 2
Referring to fig. 4-6, the present embodiment provides a method for improving local deformation of a high energy density flexible package ion battery, which is different from the conventional battery preparation method in that the following negative electrode plate is adopted.
A negative pole piece comprises a negative pole tab 21, a negative pole tab protection glue 22, a negative pole balance adhesive tape 23, a negative pole piece tape 24 and a negative pole material area 25.
The negative pole piece, negative pole dog-ear size is 17mm, the positive pole strap is 7mm apart from dog-ear line size behind the dog-ear, negative pole utmost point ear 21 width is 6mm, negative pole utmost point ear protection glue 22 width is 17mm, the balanced gluey 23 width of negative pole is 28 mm.
Example 3
Referring to fig. 7 to 8, a winding core 31 was prepared by winding the positive electrode sheet and the negative electrode sheet obtained in examples 1 and 2, with a separator added.
The distance between the pole lugs of the winding core is 10mm, and the length of the winding core termination adhesive tape 32 is 89 mm. Roll up core, roll up core top gum 33 width and be 8mm, length is 20mm
Example 4
After the packaging of the winding core in example 3 was completed and the baking was completed, the liquid injection was performed, and the soaking voltage was measured once at an interval of 2 hours after the liquid injection, and the soaking voltage curve was obtained as shown in fig. 9. And after 24h of liquid injection, measuring that the absolute value of the change of the soaking voltage is less than or equal to 2mV, and forming the battery 22h after the liquid injection. The formation surface pressure was 11kg/cm2, and after formation, the thickness difference between 6 positions of the battery was measured, and the positions were selected as shown in fig. 10, i.e., the thickness difference between position 1 and position 2 was 0.02mm, the thickness difference between position 3 and position 4 was 0.06mm, and the thickness difference between position 5 and position 6 was 0.07 mm. The formation surface pressure does not need to be adjusted according to the thickness of less than or equal to 0.05mm, when the thickness difference is 0.05-1mm, the formation surface pressure needs to be increased by 0.5kg/cm2, when the thickness difference exceeds 1mm, the formation surface pressure needs to be increased by 2kg/cm2, and when the large-batch batteries are formed, the surface pressure is executed according to 11.51kg/cm 2. And (4) adjusting the secondary sealing vacuum-pumping time to be 2S and the vacuum degree to be-90 kPa according to the coefficient of free electrolyte to be less than or equal to 0.06g/Ah of the battery after the formation is finished. And cutting edges and folding edges to obtain the flexibly packaged lithium ion battery.
Comparative example 1
The flexible package lithium ion battery of example 4 except that:
the widths of the positive pole piece tab protection glue 12 and the coating lines 1 and 2 protection glue 13 and 14 are the calculation method commonly used in the industry, the width 12 of the positive pole tab protection glue is the tab width +2mm, namely 8mm, and the widths of the coating lines 1 and 2 protection glue 13 and 14 are 6 mm.
Comparative example 2
The flexible package lithium ion battery of example 4 except that:
the width 22 of the tab protection adhesive of the negative pole piece is a calculation method which is universal in the industry, the tab width is +2mm, and the negative pole balance adhesive tape 23 is not pasted.
Comparative example 3
The flexible package lithium ion battery of example 4 except that:
the winding core is not pasted with the top glue 33.
Comparative example 4
The flexible package lithium ion battery of example 4 except that:
the negative electrode piece belt 21 is not adhered with the negative electrode balance adhesive tape 23.
Comparative example 5
The flexible package lithium ion battery of example 4 except that:
the soft package lithium ion battery does not detect the infiltration voltage after being injected with liquid
Comparative example 6
The flexible package lithium ion battery of example 4 except that:
and the free electrolyte amount of the flexible package lithium ion battery is not controlled during secondary sealing.
Comparative example 7
The flexible package lithium ion battery of example 4 except that:
the soft package lithium ion battery does not adjust the formation surface pressure according to the pre-formation result.
Examples of the experiments
The soft pack lithium ion batteries manufactured in example 4, comparative example 1, comparative example 2, comparative example 3, comparative example 4, comparative example 5, comparative example 6 and comparative example 7 were subjected to electrical property data tests, and the results are shown in table 1 and fig. 6.
TABLE 1 data of thickness variation and capacity retention after 500 weeks cycling of the batteries obtained in examples 4 and 7 comparative examples
As can be seen from the comparison of the data in table 1, the flexible package lithium ion battery manufactured according to the present invention has a smaller range of thickness change rate at 6 positions, and the capacity retention rate of the battery after cycling is also higher.
Example 5
This example provides a high energy density flexible package ion battery prepared using the method provided in example 4.
Although the present invention has been described in detail by referring to the drawings in connection with the preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made on the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and these modifications or substitutions are within the scope of the present invention/any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A local deformation improving method of a high-energy density flexible package ion battery is characterized by comprising the following steps:
setting protection glue parameters and pasting protection glue on the positive plate and the negative plate according to the protection glue parameters;
preparing a winding core by using the positive plate and the negative plate which are stuck with the protective adhesive, and preparing the winding core into a battery cell according to a battery cell preparation flow;
whether the battery is fully soaked or not is judged by detecting the stability of the soaking voltage of the battery after liquid injection:
if so, carrying out formation operation on the battery cell by using a high-temperature pressurization formation cabinet, acquiring the thicknesses of multiple positions of the battery cell in the formation operation process, and adjusting the post-formation surface pressure of the battery cell according to the thicknesses of the multiple positions of the battery cell;
calculating the coefficient of free electrolyte of the finished battery cell, setting vacuumizing time according to the coefficient of free electrolyte, vacuumizing the finished battery cell according to the vacuumizing time, and preparing the lithium ion battery by using the vacuumized battery cell.
2. The method of claim 1, wherein the setting of the protective adhesive parameters comprises:
calculating the width of the positive pole tab protection glue according to the position of the positive pole tab, wherein the width of the positive pole tab protection glue is equal to the sum of the size of the positive pole folding head and 2 mm;
calculating the width of the positive coating line protective adhesive according to the position of the positive pole lug, wherein the width of the positive coating line protective adhesive is the sum of the size of the positive pole lug metal belt from the positive pole folding line and 2 mm;
calculating the width of a negative pole tab protection glue according to the position of a negative pole tab, wherein the width of the negative pole tab protection glue is the sum of the size of a negative pole folding head and 2 mm;
and calculating the width of the negative pole piece balance glue according to the first folding width of the negative pole winding, wherein the width of the negative pole piece balance glue is the difference between the first folding width of the negative pole winding and 2 mm.
3. The method of claim 2, further comprising:
the width of the positive electrode tab protection adhesive is 6-70mm, the thickness is 0.06-0.1mm, and the material is polypropylene insulating adhesive tape; when pasting the adhesive, the adhesive is overlapped with the protective adhesive of the positive coating line by 0.5-1mm, the upper end of the adhesive is overlapped with the lower edge of the positive pole tab adhesive by 0-0.5mm, and the lower end of the adhesive exceeds the lower edge of the pole piece by 0-0.5 mm;
the width of the protective adhesive of the positive coating line is 4-72mm, the thickness is 0.01-0.06mm, the material is polypropylene insulating adhesive tape, and the two ends of the protective adhesive exceed the edges of the pole pieces by 0-0.5 mm;
the width of the negative pole tab protection glue is 6-70mm, the thickness is 0.01-0.06mm, the material is polypropylene insulation adhesive tape, the upper end overlaps 0-0.5mm with the lower edge of the negative pole tab glue when gluing, and the lower end exceeds 0-0.5mm of the lower edge of the pole piece;
the width of the negative pole piece balance adhesive tape is 18-138mm, the thickness is 0.01-0.06mm, the material is polyethylene terephthalate insulating adhesive tape, and the thickness is 0.035-0.06 mm; 0-0.5mm from the edge of the negative pole piece, 1-2mm from the negative pole material area, 1-2mm from the negative pole folding line and 1-2mm from the lower edge of the negative pole lug metal belt.
4. The method according to claim 1, wherein the preparing of the winding core by using the positive plate and the negative plate pasted with the protective adhesive comprises:
winding the positive plate and the negative plate stuck with the protective adhesive into a winding core according to the sequence of the diaphragm, the negative electrode, the diaphragm and the positive electrode;
and finally, the winding core is arranged and folded into an aluminum foil, the ending position is arranged at the central position of the distance between the anode and the cathode tabs, and a winding core with the width of 6mm is used for stopping the adhesive tape for fixing.
5. The method of claim 4, wherein the roll core termination tape has a thickness of 0.01-0.06mm, is made of polypropylene insulation tape, and is 0-2mm from the upper edge of the separator and 0-2mm from the lower edge of the separator; the thickness of the adhesive tape at the top of the winding core is 0.01-0.06mm, the material is a polypropylene insulating adhesive tape, the distance from the upper edge of the diaphragm is 0-2mm, the length of the adhesive tape is 10-30mm, and the width of the adhesive tape is 4-70 mm.
6. The method of claim 1, wherein the preparing the winding core into the battery cell according to the battery cell preparation process comprises:
and preparing the winding core into the battery cell according to the preparation processes of pressing the battery cell, measuring short circuit, pasting winding core top glue, detecting the center distance of the tabs, packaging, baking the battery cell and injecting liquid.
7. The method of claim 1, wherein during the formation operation, the method further comprises:
setting detection interval time from liquid injection to formation;
measuring the wetting voltage of the battery cell according to the interval time;
judging whether the absolute value of the difference value between the infiltration voltage measured at the current time and the infiltration voltage measured at the previous time is not more than a preset stability threshold value:
if so, judging that the current cell soakage voltage change is stable and can be formed;
if not, judging that the current battery core is not soaked by the electrolyte, and continuously placing and soaking the battery core to wait for the next soaking voltage measurement.
8. The method of claim 1, wherein the acquiring the thicknesses of the plurality of locations of the cell during the formation operation, and adjusting the post-formation pressure on the cell according to the thicknesses of the plurality of locations of the cell comprises:
symmetrically arranging a first measuring point, a second measuring point, a third measuring point, a fourth measuring point, a fifth measuring point and a sixth measuring point on the edge of the battery cell on the surface of the battery cell; the first measurement point and the second measurement point are two end points of the upper edge of the battery cell; the third measuring point and the fourth measuring point are two end points of the lower edge of the battery core; the fifth measuring point and the sixth measuring point are two end points of the central axis of the battery cell;
calculating a first thickness difference between the first measuring point and the second measuring point, a second thickness difference between the third measuring point and the fourth measuring point, and a third thickness difference between the fifth measuring point and the sixth measuring point;
judging whether the first thickness difference, the second thickness difference and the third thickness difference do not exceed a preset thickness threshold value:
if yes, the post-formation surface pressure does not need to be adjusted;
if not, increasing the formation surface pressure to the measurement point area corresponding to the thickness difference exceeding the preset thickness threshold, wherein the formation surface pressure increasing method comprises the following steps: when the thickness difference is 0.05-1mm, the formation surface pressure needs to be increased by 0.5kg/cm 2; when the thickness difference exceeds 1mm, the formation surface pressure is increased by 2kg/cm2, and the formation surface pressure range is 7-17kg/cm 2.
9. The method of claim 1, wherein calculating the free electrolyte coefficient of the completed cell and setting the evacuation time according to the free electrolyte coefficient comprises:
the coefficient of the free electrolyte is the difference obtained by subtracting the quotient of the weight of the shell body after the winding core of the battery is removed and the weight of the electrolyte on the inner wall of the shell body after the electrolyte is wiped off from the design capacity of the battery;
judging whether the coefficient of the free electrolyte is within 0.02-0.06 g/Ah:
if so, setting the vacuumizing time to be 2-3s of the conventional time;
if not, the vacuumizing time is adjusted by a step pitch of 0.5s on the basis of the conventional time, the vacuumizing time is increased when the coefficient of the free electrolyte exceeds 0.06g/Ah, and the vacuumizing time is reduced when the coefficient of the free electrolyte is lower than 0.02 g/Ah.
10. A high energy density flexible packaged ionic cell prepared by the method of any of claims 1-9.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112635714A (en) * | 2020-12-15 | 2021-04-09 | 东莞维科电池有限公司 | Preparation method of pole piece, pole piece and lithium ion battery |
| CN112665693A (en) * | 2020-12-25 | 2021-04-16 | 浙江锂威能源科技有限公司 | Method for measuring quality of free electrolyte in lithium ion battery |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202172092U (en) * | 2011-08-05 | 2012-03-21 | 山东齐星新能源科技有限责任公司 | Rubberizing structure for reeling core of lithium ion battery |
| CN203218346U (en) * | 2013-05-06 | 2013-09-25 | 山东齐星新能源科技有限责任公司 | Lithium ion battery wound core termination adhesive tape coating structure |
| CN104157914A (en) * | 2014-09-02 | 2014-11-19 | 山东齐星新能源科技有限责任公司 | High-power flexible packaged lithium ion battery and processing process thereof |
| CN106898823A (en) * | 2017-04-17 | 2017-06-27 | 深圳瑞隆新能源科技有限公司 | A kind of preparation method of water storage type flexible packing lithium ion electric core and battery |
| KR20180113819A (en) * | 2017-04-07 | 2018-10-17 | 주식회사 엘지화학 | Method and apparatus of manufacturing for battery cell |
| CN109830638A (en) * | 2019-01-16 | 2019-05-31 | 山东聚信新能源科技有限公司 | A kind of high rigidity soft package lithium ion cell polar piece and core preparation method |
-
2020
- 2020-04-17 CN CN202010307866.2A patent/CN111463497B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202172092U (en) * | 2011-08-05 | 2012-03-21 | 山东齐星新能源科技有限责任公司 | Rubberizing structure for reeling core of lithium ion battery |
| CN203218346U (en) * | 2013-05-06 | 2013-09-25 | 山东齐星新能源科技有限责任公司 | Lithium ion battery wound core termination adhesive tape coating structure |
| CN104157914A (en) * | 2014-09-02 | 2014-11-19 | 山东齐星新能源科技有限责任公司 | High-power flexible packaged lithium ion battery and processing process thereof |
| KR20180113819A (en) * | 2017-04-07 | 2018-10-17 | 주식회사 엘지화학 | Method and apparatus of manufacturing for battery cell |
| CN106898823A (en) * | 2017-04-17 | 2017-06-27 | 深圳瑞隆新能源科技有限公司 | A kind of preparation method of water storage type flexible packing lithium ion electric core and battery |
| CN109830638A (en) * | 2019-01-16 | 2019-05-31 | 山东聚信新能源科技有限公司 | A kind of high rigidity soft package lithium ion cell polar piece and core preparation method |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112635714A (en) * | 2020-12-15 | 2021-04-09 | 东莞维科电池有限公司 | Preparation method of pole piece, pole piece and lithium ion battery |
| CN112665693A (en) * | 2020-12-25 | 2021-04-16 | 浙江锂威能源科技有限公司 | Method for measuring quality of free electrolyte in lithium ion battery |
| CN112665693B (en) * | 2020-12-25 | 2023-08-15 | 浙江锂威能源科技有限公司 | Method for measuring free electrolyte quality in lithium ion battery |
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