CN109781775A - The measurement method of lithium ion battery separator shrinking percentage - Google Patents
The measurement method of lithium ion battery separator shrinking percentage Download PDFInfo
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- CN109781775A CN109781775A CN201811502319.9A CN201811502319A CN109781775A CN 109781775 A CN109781775 A CN 109781775A CN 201811502319 A CN201811502319 A CN 201811502319A CN 109781775 A CN109781775 A CN 109781775A
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- lithium ion
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- ion battery
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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
Abstract
The present invention relates to lithium ion battery separator detection technique fields, specifically provide a kind of measurement method of lithium ion battery separator shrinking percentage.The measurement method is that diaphragm is assembled into simulated battery, and then the simulated battery is placed in different temperatures and is toasted, the diaphragm size after obtaining baking, and is compared with the diaphragm size before baking, thus to obtain different temperatures lower diaphragm plate shrinking percentage.Measurement method of the invention can measure the diaphragm retracts rate under different temperatures, more importantly shrinking percentage of the high temperature lower diaphragm plate in finished battery can be measured effectively, measurement precision is high, can accurately react the shrinkage of diaphragm in actual use.
Description
Technical field
The invention belongs to lithium ion battery separator detection technique fields more particularly to a kind of lithium ion battery separator to shrink
The measurement method of rate.
Background technique
Lithium ion battery is common energy storage and conversion equipment in the modern life.With renewable energy and electronic
The development of automobile proposes increasingly higher demands to the energy density of lithium ion battery, in the requirement for meeting energy density
Under, cost decreases instead, this phenomenon makes being more widely applied for lithium ion battery.However, the peace of lithium ion battery
Full problem is always an important factor for perplexing people, since especially high capacity and power-type lithium ion battery are commercialized, lithium from
The security performance of sub- battery more people are paid attention to.
The safety of lithium ion battery depends on the thermal stability of lithium ion battery material after all.Lithium ion battery
Material mainly includes anode, cathode, diaphragm, electrolyte.The main component of diaphragm is polyolefin, and most commonly used at present is to apply
Diaphragm is covered, i.e., coats the high material of one layer of high temperature resistant, mechanical properties strength at polyolefin film surface (single or double).Diaphragm
Effect be placed between positive/negative plate, on the one hand prevent positive plate and negative electrode tab from directly contacting and causing short circuit, on the other hand permit
Perhaps ion passes freely through, but electronics cannot.There is microcellular structure, microcellular structure is as electrolyte inside common diaphragm
Carrier, adsorb a certain amount of electrolyte.
Lithium ion battery can generally undergo following exothermic reaction: decomposition → anode of SEI film during heat spent
The thermal decomposition of electrolyte and organic electrolyte are on positive and negative electrode on thermal decomposition → negative electrode material thermal decomposition → anode of material
Redox reaction.And then battery failure, explosion.And the reason of causing transient failure is exactly diaphragm because heat shrinkable is made
It is shorted at positive/negative plate or since the double action of battery core internal high temperature, high pressure makes diaphragm lose original buffer action.
Therefore the shrinking percentage test of finished product battery core septation is particularly important.
But the diaphragm that the method for assessment lithium ion battery separator shrinking percentage substantially provides supplier at present is straight
Connect be placed in baking oven toast certain time tested, it is true in finished battery that this measurement method fails feedback diaphragm
Shrinkage.Also there are Some Enterprises that will be assembled into finished battery after diaphragm and positive/negative plate winding poling group to test, still
Since finished product battery core septation has the supporting role of some tension and positive/negative plate of external application to it in winding, and
And the battery core of full electricity is easy to happen explosion at 150 DEG C；No battery core diaphragm at 160 DEG C is easy to be ejected, electroless liquid electricity
The diaphragm that core is pasted on pole piece at 145 DEG C is not readily separated, and causes dimensional measurement difficult.Due to the knot of conventional separator test
The shrinking percentage of fruit and finished product battery core septation difference, this, which is also resulted in, fails to finished product electric core membrane shrinking percentage under high temperature
Effectively detection.
Summary of the invention
The present invention provides a kind of measurement method of lithium ion battery separator shrinking percentage, it is intended to solve existing test method inspection
The lithium ion battery separator shrinking percentage and finished battery diaphragm retracts rate of survey differ greatly and can not really reflect lithium ion battery
The problems such as diaphragm shrinking percentage in application process.
The present invention is implemented as follows:
A kind of measurement method of lithium ion battery separator shrinking percentage, the measurement method are that diaphragm is assembled into simulation electricity
The simulated battery is then placed in different temperatures and toasts by Chi Zhong, obtains the diaphragm size of each baking temperature, and with baking
Diaphragm size before roasting compares, thus to obtain different temperatures lower diaphragm plate shrinking percentage.
Beneficial effects of the present invention are as follows:
Compared with the existing technology, the measurement method of lithium ion battery separator shrinking percentage provided by the invention passes through simulation electricity
Diaphragm is assembled into the shrinking percentage test that simulated battery carries out diaphragm again by pool environment, guarantees the measurement result energy of diaphragm retracts rate
The shrinkage of enough true reflection finished batteries in use, and accuracy of measurement is high, and deviation is small.
Detailed description of the invention
The technical solution in example is applied in order to illustrate more clearly of the present invention, it below will be to needed in the embodiment
Attached drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the invention, for this
For the those of ordinary skill of field, without creative efforts, it can also be obtained according to these attached drawings others
Attached drawing.
Fig. 1 be in the measurement method of lithium ion battery separator shrinking percentage provided by the invention lithium ion battery assembling after
Vertical section schematic diagram；
Fig. 2 is that embodiment 1 provided by the invention, the measurement method of 2 lithium ion battery separator shrinking percentage of embodiment measure
The shrinking percentage curve that diaphragm varies with temperature；
Wherein, 1- lithium ion battery case；The first gasket of 2-；The second gasket of 3-；4- diaphragm；5- positive plate；6- negative electrode tab.
Specific embodiment
In order to which technical problems, technical solutions and advantageous effects to be solved by the present invention are more clearly understood, below in conjunction with
Embodiment, the present invention will be described in further detail.It should be appreciated that specific embodiment described herein is only used to solve
The present invention is released, is not intended to limit the present invention.
It is worth noting that present invention sectional side elevation shown in FIG. 1, is for the simplified structure of lithium ion battery along lithium
The cross-sectional view in ion battery centre, since it needs to observe inside lithium ion cell structure, those skilled in the art are known
Its slice location is center position, thus no longer needs to draw top view, does not also need to provide the cutting along plan structure again
Line.
The present invention provides a kind of measurement method of lithium ion battery separator shrinking percentage.
The measurement method is that diaphragm is assembled into simulated battery, and the simulated battery is then placed in different temperatures
Middle baking obtains the diaphragm size of each baking temperature, and compares with the diaphragm size before baking, thus to obtain not equality of temperature
Spend lower diaphragm plate shrinking percentage.
Wherein, simulated battery diaphragm being assembled into is that positive plate, negative electrode tab, diaphragm are wound to poling group and filled
Enter in lithium ion battery case.Positive plate that simulated battery is related to, negative electrode tab are the pole piece that technical field of lithium ion uses,
Electrolyte is then substituted by solvent.
Preferably, the measurement method includes the following steps:
Step S01. places the first gasket into lithium ion battery case, and battery pole is assembled into the lithium ion battery
In shell；
Step S02. injects the solvent that boiling point is higher than highest baking temperature into the lithium ion battery case, and described
The second gasket of pole group upper surface placement, sealing treatment, and it is still aging, so that the solvent is sufficiently infiltrated the pole group, obtains institute
State simulated battery；
Step S03. at different temperatures toasts the simulated battery, and each baking temperature takes out described in a batch
The diaphragm of simulated battery, and the diaphragm size measured before its size, with baking compares, thus to obtain different temperatures lower diaphragm plate
The data of shrinking percentage.
In specific measurement process, can according to battery size, battery diaphragm, lithium ion battery case, assembling pressure into
Row is tested respectively, can also be used the lithium ion battery case of some general model, be made with the lithium ion battery case of the model
For standard.
Referring to Fig. 1, by taking the battery case of 18650 type lithium ion batteries as an example.In step S01,18650 type lithium ions are taken
Battery case 1 places the first gasket 2 in the lithium ion battery case 1, then will be according to the production work of 18650 type lithium ion batteries
The pole of winding is assembled into lithium ion battery case 1 by skill, and pole group includes diaphragm 4, positive plate 5, negative electrode tab 6.The pole group enters shell
Terminate, the second gasket 3 is placed at the top of the group of pole, it is ensured that the first gasket 2 and the second about 3 gasket clamp pole group, it is ensured that diaphragm is molten
Gasket does not melt when change, avoids the fusing of high temperature lower gasket and the diaphragm of fusing from being adhered together, causes diaphragm separation tired
It is difficult.Certainly, measurement method of the invention is not limited to 18650 type lithium ion batteries.
The fusing point of first gasket 2 of the present invention and the second gasket 3 is above highest baking temperature.Preferably, first
Gasket 2 is polyethylene terephthalate (PET), polybutylene terephthalate (PBT) (PBT), any in glass fibre
Kind.Wherein, the fusing point of PET is 260 DEG C, and the fusing point of PBT is between 225~235 DEG C, and the softening temperature of glass fibre is at 500 DEG C
More than, it can be used as gasket in the test of diaphragm retracts rate.Certainly, the first gasket 2 of the invention is not limited to listed
These types, be also possible to other fusing points, softening point reaches the material of requirement.
Preferably, the second gasket 3 is polyethylene terephthalate (PET), polybutylene terephthalate (PBT)
(PBT), any one of glass fibre.Wherein, the fusing point of PET is 260 DEG C, and the fusing point of PBT is between 225~235 DEG C, glass
The softening temperature of glass fiber is all satisfied condition at 500 DEG C or more.Certainly, the second gasket 3 of the invention is not limited to listed
These types, be also possible to other fusing points or softening point reach the material of requirement.
In step S02, to avoid in measurement process, the presence of electrolyte is not easy to dismantling and the interference to measurement, this
In the measurement of invention lithium ion battery separator shrinking percentage, in solvent alternative electrolyte injection battery core.Due to measure not equality of temperature
Shrinking percentage under degree, it is ensured that the solvent of injection does not occur explosive evaporation in maximum temperature, do not explode, do not spray, therefore has
Necessary guarantee solvent is liquid at normal temperature, and boiling point is higher than the maximum temperature of baking.Preferably, boiling point >=180 of solvent
DEG C, test request can be met, during actual test, select boiling point to meet the requirements according to the maximum temperature of baking molten
Agent.Used solvent should meet room temperature to be existed in liquid form, and during Baking out, it does not chemically react.
Preferably, solvent is N-Methyl pyrrolidone (NMP) or dimethyl sulfoxide (DMSO), wherein the boiling point of NMP
It is 203 DEG C, the boiling point of DMSO is 189 DEG C, can satisfy requirement of the invention.Certainly, solvent of the invention is not limited to
Both above-mentioned solvents are also possible to the solvent that other boiling points are higher than 180 DEG C.
It is worth noting that, in the present invention, the injection of solvent and the sequence of the second gasket 3 are not required particularly, can be with
It is directly to place the second gasket 3 after pole group enters shell, is also possible to pole group and enters first to inject solvent after shell and place the second gasket 3 again.
In the injection rate of above-mentioned solvent, with traditional lithium-ion battery production process, the electricity of the lithium ion battery of corresponding model
The injection rate for solving liquid is as identical as possible.Preferably, the reservoir quantity of the solvent is the lithium-ion battery electrolytes note of corresponding model
The 70%~100% of liquid measure.Such as by taking 18650 types as an example, the electrolyte of the injection rate of solvent and 18650 type lithium ion batteries is infused
It is identical to enter amount, other than guaranteeing infiltration, the difference with really injection electrolyte can also be reduced, improve its simulation accuracy, this
The injection rate of the lithium ion battery of corresponding model may be not achieved in the injection rate maximum value of some outer solvents, infused at this time with solvent
Enter subject to amount maximum value.
Above-mentioned sealing treatment is the equivalent in meaning of the sealing treatment expression produced with general lithium ion battery, that is, carries out three
Envelope sealing, is aged also consistent with the meaning that ageing involved in general lithium ion battery production process is stated, the mesh of ageing
Be provided to so that pole piece is sufficiently infiltrated.
Preferably, digestion time is 24~48h.
In step S03, the simulated battery that step S02 can be obtained, which is placed in baking oven, to be toasted, it also can be used
His roasting plant.
In order to save baking number and baking time, measurement efficiency is improved, can simultaneously be obtained a collection of step S02
Finished product is placed in roasting plant, and is toasted according to the sequence from low-temperature-rise to high temperature, in the temperature of each measurement point,
A collection of simulated battery is taken out, battery core, separating diaphragm 4 are disassembled after cooled to room temperature, and carry out to isolated diaphragm 4
Dimensional measurement.Remaining simulated battery then stays in roasting plant and relays temperature of continuing rising, until next measurement point temperature, further takes out one
Simulated battery is criticized, is cooled to room temperature, according to above-mentioned operation, the size of measuring diaphragm 4.
The diaphragm size that each temperature measurement obtains can be obtained compared with the diaphragm size before winding (before baking)
The shrinking percentage of diaphragm at different temperatures.In order to preferably compare shrinking percentage, can before winding, to diaphragm to be spooled into
Row dimensional measurement can also cut the diaphragm of the identical size of a batch as blank control before winding, measure blank control diaphragm
Size.
Above-mentioned baking temperature is preferably 105~200 DEG C, further preferably at 160~200 DEG C.Within this temperature range,
The shrinking percentage of diaphragm can be obtained.According to the aforementioned baking sequence according to from low temperature to high temperature, 105 DEG C can be first warming up to,
Constant temperature toasts 30~60min at 105 DEG C, takes out a collection of simulated battery cooled to room temperature, measures the diaphragm ruler of the batch
It is very little, calculate average value；Then be successively warming up in order 110 DEG C, 115 DEG C, 120 DEG C, 125 DEG C, 130 DEG C, 135 DEG C, 140 DEG C,
145 DEG C, 150 DEG C, 155 DEG C, 160 DEG C, 165 DEG C, 170 DEG C, 175 DEG C, 180 DEG C, 190 DEG C, 195 DEG C, 200 DEG C, and in each survey
30~60min is kept the temperature at a temperature of amount point.Its heating rate does not require particularly, and the temperature spot measured, also without special
Requirement, cited only the temperature interval section of general measure and temperature spot, those skilled in the art institute according to the present invention
The thinking of offer, can also be in the measurement of other temperature spots progress diaphragm size, as long as ensuring in measurement process, the boiling of solvent
The maximum temperature that the fusing point of point, the first gasket 2 and the second gasket 3 is above baking is feasible.Such as, highest baking temperature is 150
DEG C, then the boiling point of the solvent selected is higher than 150 DEG C, the first gasket 2, the second gasket fusing point be higher than 150 DEG C；For another example, highest is dried
Roasting temperature is 160 DEG C, then the boiling point for the solvent selected is higher than 160 DEG C, the first gasket 2, the second gasket fusing point be higher than 160 DEG C；
For another example, highest baking temperature is 170 DEG C, then the boiling point of the solvent selected is higher than 170 DEG C, the first gasket 2, the second gasket it is molten
Point is higher than 170 DEG C；For another example, highest baking temperature is 180 DEG C, then the boiling point of the solvent selected is higher than 180 DEG C, the first gasket 2,
The fusing point of second gasket is higher than 180 DEG C；For another example, highest baking temperature is 190 DEG C, then the boiling point for the solvent selected is higher than 190
DEG C, the first gasket 2, the second gasket fusing point be higher than 190 DEG C；For another example, highest baking temperature is 200 DEG C, then the solvent selected
Boiling point be higher than 200 DEG C, the first gasket 2, the second gasket fusing point be higher than 200 DEG C.
Specifically, diaphragm retracts rate of the invention can be calculated using following public formula (I):
Wherein, L0It indicates diaphragm original size, can be the diaphragm original size of blank control, before being also possible to winding
Size；
L1Size after indicating diaphragm retracts.
In the present invention, the positive plate that is related to, negative electrode tab are the general pole piece of technical field of lithium ion, as positive plate can
To be that LiFePO4 isoreactivity material is attached on copper foil according to general positive plate production technology, negative electrode tab can be graphite etc.
Active material is attached on aluminium foil according to general anode piece production technology, to save length, is no longer aligned with pole piece, cathode herein
Piece expansion repeats.
Since dystectic upper lower gasket fusing point that the present invention uses is relatively high, it is higher than highest baking temperature, at high temperature
Without melting or ruckbildung, bonding will not be played the role of to diaphragm, because of the mistake of the diaphragm retracts dimensional measurement without caused by
Difference；The high boiling solvent alternative electrolyte that the present invention uses, phenomena such as boiling will not occur at high temperature, decompose, to diaphragm
It can influence less, to be disassembled diaphragm and be easy to separate with positive/negative plate, so that the diaphragm size measurement after shrinking is more accurate.
To better illustrate technical solution of the present invention, it is illustrated combined with specific embodiments below.
Embodiment 1
The present embodiment 1 provides a kind of measurement method of lithium ion battery separator shrinking percentage, and the diaphragm being related to is Dong Gao production
12+4 model diaphragm include the following steps by taking 18650 type lithium ion batteries as an example.
(1) takes 15 18650 type lithium ion battery cases, and the first PET sheet is placed in bottom in each battery case, makes the
One PET sheet just covers battery case bottom；It cuts the identical diaphragm of a collection of size, and a portion is used for and anode
Piece, negative electrode tab wind poling group, and another part is used as and refers to group, the pole group that winding obtains are entered shell, and put at the top of the group of pole
The second PET sheet is set, so that the second PET sheet just covers pole group top.
(2) injects 5.0gNMP into each battery case, and so that NMP is quickly infiltrated pole piece by vacuum tank, then carries out
The sealing of three envelopes, room temperature is still aging for 24 hours, so that positive/negative plate is further sufficiently infiltrated.
(3) 15 finished products that obtains above-mentioned steps (2), which are placed in baking oven, toasts, and is warming up to 105 DEG C, keeps the temperature 30min,
3 finished product cooled to room temperatures are then taken out, disassembles, isolate positive plate, negative electrode tab and diaphragm, using vernier caliper pair
The diaphragm of acquisition carries out dimensional measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage,
Average value is calculated according to shrinking percentage, and is documented in table 1；
Remaining 12 finished products then continue to heat up in oven, are warming up to 130 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 1；
Remaining 9 finished products then continue to heat up in oven, are warming up to 145 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 1；
Remaining 6 finished products then continue to heat up in oven, are warming up to 160 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 1；
Remaining 3 finished products then continue to heat up in oven, are warming up to 180 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 1.
The eastern highland 12+4 type diaphragm retracts rate (%) of table 1
Embodiment 2
The present embodiment 2 provides a kind of measurement method of lithium ion battery separator shrinking percentage, and the diaphragm being related to is Dong Gao production
14+2 model diaphragm, by taking 18650 type lithium ion batteries as an example, comprising the following steps:
(1) takes 15 18650 type lithium ion battery cases, and the first PET sheet is placed in bottom in each battery case, makes the
One PET sheet just covers battery case bottom；It cuts the identical diaphragm of a collection of size, and a portion is used for and anode
Piece, negative electrode tab wind poling group, and another part is used as and refers to group, the pole group that winding obtains are entered shell, and put at the top of the group of pole
The second PET sheet is set, so that the second PET sheet just covers pole group top.
(2) injects 5.0g NMP into each battery case, and so that NMP is quickly infiltrated pole piece by vacuum tank, with laggard
The sealing of three envelope of row, room temperature is still aging for 24 hours, so that positive/negative plate is further sufficiently infiltrated.
(3) 15 finished products that obtains above-mentioned steps (2), which are placed in baking oven, toasts, and is warming up to 105 DEG C, keeps the temperature 30min,
3 finished product cooled to room temperatures are then taken out, disassembles, isolate positive plate, negative electrode tab and diaphragm, using vernier caliper pair
The diaphragm of acquisition carries out dimensional measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage,
Average value is calculated according to shrinking percentage, and is documented in table 1；
Remaining 12 finished products then continue to heat up in oven, are warming up to 130 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 2；
Remaining 9 finished products then continue to heat up in oven, are warming up to 145 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 2；
Remaining 6 finished products then continue to heat up in oven, are warming up to 160 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 2；
Remaining 3 finished products then continue to heat up in oven, are warming up to 180 DEG C, keep the temperature 30min, rear to take out 3 finished products certainly
It is so cooled to room temperature, disassembles, isolates positive plate, negative electrode tab and diaphragm, size is carried out using diaphragm of the vernier caliper to acquisition
Measurement, records its data, and compare with the size of reference group diaphragm, calculates its shrinking percentage, is calculated according to shrinking percentage average
Value, and be documented in table 2.
The eastern highland 14+2 type diaphragm retracts rate (%) of table 2
The data for the diaphragm retracts rate that embodiment 1 and embodiment 2 obtain are depicted as curve, specifically as shown in Fig. 2.By
After Fig. 2 is it is found that as the temperature rises, diaphragm retracts rate also becomes larger, and temperature increases to a certain extent, the contraction of diaphragm
Rate does not continue to rise, and illustrates that it has reached the maximum shrinking percentage.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Made any modifications, equivalent replacements, and improvements etc., should all be included in the protection scope of the present invention within mind and principle.
Claims (10)
1. a kind of measurement method of lithium ion battery separator shrinking percentage, which is characterized in that the measurement method is to assemble diaphragm
Into simulated battery, then the simulated battery is placed in different temperatures and is toasted, obtains the diaphragm size of each baking temperature,
And compared with the diaphragm size before baking, thus to obtain different temperatures lower diaphragm plate shrinking percentage.
2. the measurement method of lithium ion battery separator shrinking percentage as described in claim 1, which is characterized in that the measurement method
Include the following steps:
The first gasket is placed into lithium ion battery case, and battery pole is assembled into the lithium ion battery case；
It injects solvent into the lithium ion battery case, and places the second gasket in pole group upper surface, sealing treatment, and it is quiet
Ageing is set, so that the solvent is sufficiently infiltrated the pole group, obtains the simulated battery；
The simulated battery is toasted at different temperatures, each baking temperature take out a batch simulated battery every
Film, and the diaphragm size measured before its size, with baking compares, thus to obtain the data of different temperatures lower diaphragm plate shrinking percentage.
3. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that the boiling of the solvent
Point is higher than the maximum temperature of baking.
4. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that first gasket
It is higher than highest baking temperature with the melting temperature of the second gasket.
5. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that the solvent is N-
Any one of methyl pyrrolidone, dimethyl sulfoxide.
6. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that first gasket
For any one of polyethylene terephthalate, polybutylene terephthalate (PBT), glass fibre；And/or described second
Gasket is any one of polyethylene terephthalate, polybutylene terephthalate (PBT), glass fibre.
7. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that the baking temperature
Not less than 160 DEG C.
8. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 7, which is characterized in that the baking temperature
Range is 160~200 DEG C.
9. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that the roasting mode
To be toasted according to the sequence from low temperature to high temperature.
10. the measurement method of lithium ion battery separator shrinking percentage as claimed in claim 2, which is characterized in that the solvent
Reservoir quantity is the 70%~100% of the lithium-ion battery electrolytes reservoir quantity of corresponding model.
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| CN201811502319.9A CN109781775A (en) | 2018-12-10 | 2018-12-10 | The measurement method of lithium ion battery separator shrinking percentage |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112683942A (en) * | 2020-12-25 | 2021-04-20 | 东莞维科电池有限公司 | Diaphragm thermal shrinkage assessment method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112683942A (en) * | 2020-12-25 | 2021-04-20 | 东莞维科电池有限公司 | Diaphragm thermal shrinkage assessment method |
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