CN218470855U - Testing device for diaphragm - Google Patents

Abstract

The utility model discloses a testing arrangement for diaphragm, include: a first die and a second die, the first die comprising: a first insulator and a first electrode; the second die includes: the first electrode is opposite to the second electrode; the second insulating part is provided with a storage bin, the first insulating part coats the side face of the first electrode, the second insulating part coats the side face of the second electrode, so that only the end face of the first electrode and the end face of the second electrode are exposed out of the storage bin, the diaphragm is arranged in the storage bin, and the first insulating part is suitable for extending into the storage bin and pressing the diaphragm. Therefore, in the test process, the side surfaces of the first electrode and the second electrode generate capacitance interference, impedance fluctuation is improved, test accuracy and consistency can be improved, test steps are few, difficulty is low, a button cell or soft package electrode structure does not need to be processed, and test cost is lower.

Description

Testing device for diaphragm

Technical Field

The utility model belongs to the technical field of electric core test technique and specifically relates to a testing arrangement for diaphragm is related to.

Background

The lithium ion battery mainly comprises a positive pole piece, a negative pole piece, a diaphragm and electrolyte, wherein the diaphragm is mainly used for isolating the positive pole piece and the negative pole piece, preventing electrons from passing through but allowing ions to pass through and providing a micropore channel for the transmission of lithium ions. When the battery is out of control thermally, the internal temperature of the battery rises sharply, the micropores of the diaphragm are closed, the further thermal reaction of the battery can be prevented, and the diaphragm fails and the positive and negative pole pieces are contacted with each other along with the continuous rise of the internal temperature of the battery and the exceeding of the melting temperature of the diaphragm. Therefore, the performance of the separator is directly related to the safety of the lithium battery.

The ion conductivity of the diaphragm can directly reflect the real level of the diaphragm conducting lithium ions in the battery, and data support is provided for the design, model selection and performance test of the diaphragm.

In the related art, the ion conductivity of the diaphragm is generally tested by manufacturing a button cell and a soft package battery or by using a module, and small differences in materials, sizes, manufacturing methods and the like of the button cell and the soft package battery have large influence on impedance, poor precision and high cost; and adopt the mould to carry out the technical scheme of measuring, the mould causes electric capacity to disturb easily, causes impedance fluctuation, and accuracy, uniformity are relatively poor.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, an object of the present invention is to provide a testing device for a diaphragm, which has small impedance fluctuation, high accuracy and consistency, and low cost.

According to the utility model discloses a testing arrangement for diaphragm, include: a first die and a second die, the first die comprising: a first insulator and a first electrode; the second die includes: the first electrode is opposite to the second electrode; the second insulating part is provided with a storage bin, the first insulating part coats the side face of the first electrode, the second insulating part coats the side face of the second electrode, so that only the end face of the first electrode and the end face of the second electrode are exposed out of the storage bin, the diaphragm is arranged in the storage bin, and the first insulating part is suitable for extending into the storage bin and pressing the diaphragm.

According to the utility model discloses a testing arrangement for diaphragm through setting up first insulating part and second insulating part to make first electrode and second electrode only the terminal surface expose in the feed bin, in order to contact with electrolyte, on the one hand, can avoid in the test process, the side of first electrode and second electrode produces electric capacity and disturbs, improves the impedance fluctuation, can improve test accuracy and uniformity; on the other hand, the area measurement of the regions opposite to the first electrode and the second electrode can be omitted in the test process, the test steps are few, the difficulty is low, the button cell or soft package electrode structure does not need to be processed, and the test cost is lower.

According to some embodiments of the invention, the first insulating member comprises: first plate body and setting are in first plate body orientation the first fixed block of second mould one side, first plate body with the second insulating part links to each other, first fixed block is suitable for stretching into the feed bin.

Furthermore, a containing groove is formed in the first fixing block, the first electrode is arranged in the containing groove, so that one end face of the first electrode is exposed out of the storage bin, and the end face of the first electrode is located above the end face of the first fixing block to form a first groove.

Further, still have on the first fixed block with the mounting hole of storage tank intercommunication, be provided with the installation department on the other end of first electrode, the installed part wears to establish the mounting hole and links to each other with the installation department.

Further, a first conducting strip is arranged on the mounting piece and used for being connected with the electrochemical workstation.

In some embodiments, the second insulator comprises: the second plate body is connected with the first insulating part, and the second fixing block is provided with the storage bin.

Furthermore, the second fixed block is further provided with an installation groove communicated with the storage bin, the second electrode extends into the installation groove, so that the end face of the second electrode is exposed out of the storage bin, and the end face of the second electrode is positioned below the bottom wall of the storage bin to form a second groove.

Optionally, the silo comprises: the inner diameter of the first bin section is larger than the outer diameter of a first fixing block of the first insulating part, and a first overflow groove is defined between the first fixing block and the second bin section.

Furthermore, a chamfer is arranged at one end, facing the second insulating part, of the first fixing block, and a second overflow tank is defined between the chamfer and the second bin section.

Further, the second electrode includes: the electrode comprises an electrode body and a protruding portion, wherein the protruding portion extends into the mounting groove, and the electrode body, the second plate body and the first insulating part are connected through a fastening piece.

In some embodiments, a second conductive tab is disposed on the electrode body for connection to an electrochemical workstation.

According to some embodiments of the invention, a seal is further provided between the first die and the second die.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a testing device according to an embodiment of the present invention;

fig. 2 is a schematic view of a first insulator, fastener, and seal in accordance with an embodiment of the present invention;

fig. 3 is a schematic view of a first electrode and a first conductive sheet according to an embodiment of the invention;

FIG. 4 is a schematic view of a first die, a fastener, and a seal according to an embodiment of the present invention;

fig. 5 is a schematic view of a second insulator according to an embodiment of the present invention;

fig. 6 is a schematic view of a second electrode according to an embodiment of the invention;

fig. 7 is a schematic view of a second die according to an embodiment of the present invention;

fig. 8-10 are data parameter comparison graphs of the testing device of the present invention with comparative example 1 and comparative example 2.

Reference numerals:

the number of test units 100, membranes 200,

a first die 10, a first insulating member 11, a first plate 111, a first fixing block 112, a receiving groove 1121, a mounting hole 1122, a first electrode 12, a mounting portion 121, a mounting member 13, a first conductive sheet 14,

a second die 20, a second insulating member 21, a second plate 211, a second fixing block 212, a storage bin 2121, a first storage bin section 21211, a second storage bin section 21212, a mounting groove 2122, a second electrode 22, an electrode body 221, a bulge 222, a second conducting strip 23,

the combination of the fastener 30, the seal 40,

a first overflow tank a, a second overflow tank b, a first tank c and a second tank d.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

A test device 100 for a membrane 200 according to an embodiment of the present invention is described below with reference to fig. 1-10.

As shown in fig. 1, 4 and 7, a testing device 100 for a diaphragm 200 according to an embodiment of the present invention includes: a first die 10 and a second die 20, the first die 10 being configurable to move toward or away from the second die 20; or the second die 20 is configured to move toward or away from the first die 10; or the first die 10 and the second die 20 move toward or away from each other to selectively close the pocket 2121 of the second die 20.

As shown in fig. 4 and 7, the first die 10 includes: a first insulator 11 and a first electrode 12; the second die 20 includes: a second insulating member 21 and a second electrode 22, the first electrode 12 facing the second electrode 22; the second insulating member 21 has a bin 2121, the first insulating member 11 covers a side of the first electrode 12, the second insulating member 21 covers a side of the second electrode 22, such that only end surfaces of the first electrode 12 and the second electrode 22 are exposed to the bin 2121, the diaphragm 200 is disposed in the bin 2121, and the first insulating member 11 is adapted to extend into the bin 2121 and press against the diaphragm 200.

Specifically, during the testing process, the electrolyte may be injected into the bin 2121, the separator 200 is n-layered, n is greater than or equal to 1, and is pressed against the bin 2121 through the cooperation of the first insulating member 11 and the second insulating member 21, the side surface of the first electrode 12 is covered by the first insulating member 11 to prevent the side surface of the first electrode 12 from contacting the electrolyte, and similarly, the side surface of the second electrode 22 is covered by the second insulating member 21 to prevent the side surface of the second electrode 22 from contacting the electrolyte, and the first electrode 12 and the second electrode 22 are disposed opposite to each other on two sides of the separator 200.

The utility model discloses testing arrangement 100, first electrode 12 and second electrode 22 all link to each other with the electrochemistry workstation, first resistance (diaphragm 200) when can measuring diaphragm 200 and being in the electrolyte environment (the resistance of testing arrangement 100 and electrolyte with) and the second resistance (electrolyte and testing arrangement 100 with) when not setting up diaphragm 200 in the feed bin 2121, both make behind the poor can further calculate the ionic conductivity of individual layer diaphragm 200 or multilayer diaphragm 200 according to first electrode 12 and second electrode 22 just to the area value, and can be through the diaphragm 200 of changing different electrolytes and different materials, can realize the ionic conductivity of different grade type diaphragm 200 under the electrolyte or the same electrolyte environment of difference, other material losses have been avoided, when need test the diaphragm 200 impedance under the different temperatures, maintain above-mentioned step unchangeable, and can through setting up the heating member, place in operations such as oven, realize the measurement of diaphragm 200 impedance under the different temperatures.

That is to say, the utility model discloses testing arrangement 100 can realize the impedance test of diaphragm 200 through the making difference of first resistance and second resistance to can further estimate out other electrochemistry volume, the electrophysical volume of diaphragm 200 such as ionic conductivity, also can realize different temperatures, the measuring and calculating of diaphragm 200 impedance and other electrochemistry volume, the electrophysical volume under the different service environment through changing testing arrangement 100 environment.

Illustratively, the first insulator 11 may be configured as a cladding or provided with a groove structure, while the side of the first electrode 12 is clad or located within the groove structure, the side wall of the groove structure being opposite to the side of the first electrode 12 to clad the side of the first electrode 12; correspondingly, the second insulator 21 may be configured as a covering member or a groove structure, and the side surface of the second electrode 22 is covered or located in the groove structure, and the side wall of the groove structure is opposite to the side surface of the second electrode 22 to cover the side surface of the second electrode 22.

It can be understood that the first electrode 12 faces the second electrode 22, the facing area is kept constant, the measurement is not required to be directly converted based on the setting parameters, the step of measuring and calculating the facing area can be omitted, the precision is preliminarily improved, the test difficulty is reduced, the side surface of the first electrode 12 and the side surface of the second electrode 22 are not in contact with the electrolyte, only the end surface of the first electrode 12 facing the second electrode 22 is in contact with the electrolyte, the capacitance interference in the test process can be avoided, the impedance fluctuation is improved, the test accuracy and consistency are improved, and the test precision is improved.

Furthermore, the utility model discloses diaphragm 200 directly sets up in the mould, need not to process into button cell, laminate polymer battery isotructure in order to carry out ionic conductivity test, when improving the precision, can effective reduce cost.

According to the utility model discloses a testing arrangement 100 for diaphragm 200, through setting up first insulator 11 and second insulator 21 to make first electrode 12 and second electrode 22 only the terminal surface expose in feed bin 2121, in order to contact with electrolyte, on the one hand, can avoid in the test process, the side of first electrode 12 and second electrode 22 produces the electric capacity interference, and it is undulant to improve the impedance, can improve test accuracy and uniformity; on the other hand, the area measurement of the regions opposite to the first electrode 12 and the second electrode 22 can be omitted in the test process, the test steps are few, the difficulty is low, the button cell or soft package electrode structure does not need to be processed, and the test cost is lower.

As shown in fig. 2, 3 and 4, according to some embodiments of the present invention, the first insulating member 11 includes: the first plate 111 and the first fixing block 112 are disposed on a side of the first plate 111 facing the second die 20, the first plate 111 is connected to the second insulating member 21, and the first fixing block 112 is adapted to extend into the bin 2121.

Specifically, can set up first fixed block 112 on the middle zone of first plate body 111, first fixed block 112 constructs for the projection structure, and first fixed block 112 can stretch into in the feed bin 2121 to the terminal surface through first fixed block 112 is pressed and is supported the diaphragm 200 that is located the feed bin 2121, can improve the fixed stability to diaphragm 200.

Referring to fig. 2 and 3, the first fixed block 112 is provided with an accommodating groove 1121, the first electrode 12 is disposed in the accommodating groove 1121, such that an end surface of the first electrode 12 is exposed from the bin 2121, and the end surface of the first electrode 12 is located above the end surface of the first fixed block 112 to form a first groove c.

That is, the end surface of the first fixed block 112 is pressed against the diaphragm 200, and the end surface of the first electrode 12 is positioned above the end surface of the first fixed block 112, so that the diaphragm 200 is spaced apart from the first electrode 12.

Therefore, when the impedance of the diaphragm 200 is tested at different temperatures, even if the testing temperature exceeds the melting temperature of the diaphragm 200, the molten diaphragm 200 is not adhered to the end surface of the first electrode 12, so that the impedance interference generated when the diaphragm 200 is adhered to the first electrode 12 can be avoided, the impedance testing precision of the testing device 100 at different testing temperatures is improved, and the closed pore temperature of the diaphragm 200, the failure temperature of the diaphragm 200 and the like of the diaphragm 200 can be indirectly measured according to the impedance values at different temperatures.

According to some embodiments of the present invention, the first fixing block 112 further has a mounting hole 1122 communicating with the accommodating groove 1121, the other end of the first electrode 12 is provided with the mounting portion 121, and the mounting member 13 penetrates through the mounting hole 1122 and is connected to the mounting portion 121.

Specifically, installed part 13 is constructed as the bolt, and the mounting hole 1122 can be stretched into by one side that first plate body 111 deviates from second insulating part 21 to the bolt and installation department 121 screw fastening, in order to realize the fixed of first electrode 12 in storage tank 1121, storage tank 1121 and first electrode 12 interference fit or can set up the sealing layer between the side of first electrode 12 and the inner wall of storage tank 1121, in order to avoid electrolyte to dip the clearance between first electrode 12 and the storage tank 1121, improve the utility model discloses the stability and the reliability of the technological effect of the electric capacity interference of avoiding the side production of first electrode 12.

Further, a first conductive sheet 14 is provided on the mount 13, the first conductive sheet 14 being adapted to be connected to an electrochemical workstation.

In other words, the first conductive sheet 14 has a connecting arm and a fixing arm, the fixing arm is connected to the mounting member 13 or is fixed to the end face of the first electrode 12 facing away from the second electrode 22 via the mounting member 13, and the electrochemical workstation is connected to the first electrode 12 via the first conductive sheet 14.

As shown in fig. 5, 6 and 7, in some embodiments, the second insulating member 21 includes: the second plate body 211 is connected with the first insulating part 11, and the second fixing block 212 is provided with a bin 2121.

Particularly, a second fixing block 212 extending away from the first plate body 111 can be arranged in the middle area of the second plate body 211, a bin 2121 is formed in one side, facing the first plate body 111, of the second fixing block 212, so that the diaphragm 200 can be placed and electrolyte can be injected, the first fixing block 112 can extend into the bin 2121 formed in the second fixing block 212, a test space is built through the first fixing block 112 and the second fixing block 212, the test space is spaced from the outside, the use environment is closer to the use environment, the influence of environmental errors on test results can be effectively reduced, and the test precision is improved.

As shown in fig. 7, the second fixing block 212 further has a mounting groove 2122 communicated with the bin 2121, the second electrode 22 extends into the mounting groove 2122, such that an end surface of the second electrode 22 is exposed to the bin 2121, and the end surface of the second electrode 22 is located below a bottom wall of the bin 2121 to form a second groove d.

That is, the membrane 200 is located on the bottom wall of the cartridge 2121, and the end surface of the second electrode 22 is located below the bottom wall of the cartridge 2121, so that the membrane 200 is spaced apart from the second electrode 22.

Therefore, when the impedance of the diaphragm 200 is measured at different temperatures, even if the measurement temperature exceeds the melting temperature of the diaphragm 200, the molten diaphragm 200 is not adhered to the end surface of the second electrode 22, so that the impedance interference generated when the diaphragm 200 is adhered to the second electrode 22 can be avoided, the impedance measurement accuracy of the testing device 100 at different measurement temperatures can be improved, and the closed pore temperature of the diaphragm 200, the failure temperature of the diaphragm 200 and the like of the diaphragm 200 can be indirectly measured according to the impedance values at different temperatures.

Preferably, the first groove c is defined between the first insulating member 11 and the first electrode 12, and the second groove d is defined between the second insulating member 21 and the second electrode 22, so that the first electrode 12 and the second electrode 22 do not stick to the diaphragm 200 when the diaphragm 200 is in a molten state, and the testing accuracy of the testing device 100 can be effectively improved.

As shown in fig. 1, the hopper 2121 includes: a first barrel section 21211 and a second barrel section 21212 which have successively reduced inner diameters, wherein the inner diameter of the first barrel section 21211 is larger than the outer diameter of a first fixing block 112 of the first insulating member 11, and a first overflow tank a is defined between the first fixing block 112 and the second barrel section 21212; the end of the first fixing block 112 facing the second insulating member 21 is provided with a chamfer, and a second overflow groove b is defined between the chamfer and the second bin section 21212.

Specifically, the first and second bunker sections 21211 and 21212 are both cylindrical shaft sections, the inner diameter of the second bunker section 21212 is consistent with the outer diameter of the first fixing block 112, the first fixing block 112 is inserted into the second bunker section 21212, and the solid structure of the first fixing block 112 extending into the bunker 2121 can cause the electrolyte to overflow outwards, so that the second overflow tank b defined between the chamfer and the second bunker section 21212 and the second overflow tank b defined between the first bunker section 21211 and the first fixing block 112 can avoid the overflow of the electrolyte, thereby improving the safety and reliability in the testing process.

It should be noted that each of the first die 10 and the second die 20 may be provided with a handle to facilitate the injection of the electrolyte, the placement of the diaphragm 200, and the clamping operation of the first die 10 and the second die 20.

As shown in fig. 6, the second electrode 22 includes: the electrode body 221 and the protrusion 222, the protrusion 222 extends into the mounting groove 2122, and the electrode body 221, the second plate 211 and the first insulator 11 are connected by the fastener 30.

The second electrode 22 may be configured as a metal plate, a groove is formed in the metal plate, the groove is used for accommodating the second fixing block 212, so that the testing device 100 is more flat, a protrusion 222 is formed in a middle area of the groove, the protrusion 222 corresponds to the mounting groove 2122 of the second fixing block 212, the protrusion 222 extends into the mounting groove 2122, and an end surface of the protrusion 222 is lower than a bottom wall of the bin 2121, so as to define a second groove d.

Therefore, on the premise that the whole testing device 100 is more flat and convenient to operate in the testing process, the structure of the second electrode 22 is more reasonable, and the testing precision can be effectively improved.

Furthermore, the first plate 111, the second plate 211 and the electrode body 221 may be connected by the fastening member 30, so that the assembly of the testing device 100 is more simple and convenient.

In some embodiments, a second conductive strip 23 is disposed on the electrode body 221, the second conductive strip 23 being for connection to an electrochemical workstation.

In other words, the second conductive sheet 23 is connected to the electrode body 221, so that the electrochemical workstation is connected to the protruding portion 222 through the second conductive sheet 23, so as to form a complete loop through the first conductive sheet 14, the first electrode 12, the second conductive sheet 23 and the second electrode 22, and facilitate connection to the electrochemical workstation for performing a corresponding test.

As shown in fig. 1, according to some embodiments of the present invention, a sealing member 40 is further disposed between the first die 10 and the second die 20.

Therefore, after the first plate 111, the second plate 211 and the electrode body 221 are pressed and fixed by the fastening member 30, the sealing member 40 can block the gap between the first plate 111 and the second plate 211 to prevent the volatilization and diffusion of the electrolyte, thereby improving the sealing performance of the test space.

For example, a sealing groove may be formed in the first plate 111 and/or the second plate 211, and the sealing element 40 is disposed in the sealing groove, and a portion protruding out of the sealing groove may be pressed and deformed to fill a gap between the first plate 111 and the second plate 211, so as to seal the storage bin.

To sum up, the utility model discloses a testable diaphragm 200 impedance, and the test result is accurate, simple operation's testing arrangement 100, when changing different diaphragm 200, only need to change diaphragm 200 and electrolyte, assembled first mould 10, the fastener 30 of screwing can, simultaneously based on testing arrangement 100+ electrolyte + diaphragm 200's first resistance and not add diaphragm 200 and only add the second resistance of electrolyte, can obtain diaphragm 200's impedance, and then calculate diaphragm 200's ionic conductivity.

Meanwhile, in order to reduce the capacitive interference of the side surfaces of the first electrode 12 and the second electrode 22 in the testing process, the testing device 100 embeds the first electrode 12 into the first insulating part 11 and embeds the second electrode 22 into the second insulating part 21 to respectively define a first groove c and a second groove d, both electrodes do not contact with the diaphragm 200 in the testing state, and the diaphragm 200 is fixed by the insulating part wrapping the electrodes, so that the diaphragm 200 is not adhered to the surfaces of the electrodes even if the diaphragm 200 is molten in a high-temperature state, the impedance change of the diaphragm 200 at different temperatures can be accurately tested, and the indirect testing of data such as the closed pore temperature and the failure temperature of the diaphragm 200 can be realized.

The first insulating member 11 and the second insulating member 21 need to be made of electrolyte corrosion resistant and high temperature resistant materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polypropylene, polyethylene, etc., the first electrode 12 and the second electrode 22 need to be made of metal materials with good thermal conductivity, such as copper, stainless steel, aluminum, nickel, etc., and when the impedance of the diaphragm 200 is tested at different temperatures, the first electrode 12 and the second electrode 22 can be ensured to conduct heat rapidly.

Next, referring to fig. 8, 9 and 10, the test results of the test apparatus 100 according to the embodiment of the present invention are compared with those of comparative example 1 and comparative example 2.

The test procedure was as follows:

the separator 200 is fixed between the first mold 10 and the second mold 20, neither the first electrode nor the second electrode 22 is in contact with the separator 200, and only the lower end surface of the first electrode 12 and the upper end surface of the second electrode 22 are in contact with the electrolyte.

The test was performed by connecting the first conductive sheet 14 and the second conductive sheet 23 with an electrochemical workstation.

First, the first resistance values of the test apparatus 100, the electrolyte, and the separator 200 were measured. The diaphragms 200 with different layers are respectively marked with first resistance values R1 and R2.... Rn, the test is respectively 1-layer, 2-layer and 3-layer diaphragms 200, each layer is tested with 3 parallel samples which are respectively expressed by R1-1, R1-2 and R1-3 \8230;.

Further, the resistance value, R0, of the test apparatus 100 and the electrolyte was obtained without placing the separator 200.

An average resistance value R = (Rn-R0)/n of the separator 200 is calculated.

The conductivity σ = d/RS of the separator 200 is calculated, where d is the thickness of the separator 200 and S is the area of the region where the first electrode 12 and the second electrode 22 face each other.

When testing the resistance values of the diaphragm 200 at different temperatures, the thermocouple is connected to the first conductive sheet 14 and the second conductive sheet 23, and the assembled testing device 100 is placed in an oven, so that the resistance values of the diaphragm 200 at different temperatures can be tested, and the ionic conductivity of the diaphragm 200 at different temperatures can be calculated.

The utility model discloses the test result is seen in figure 8.

The difference between the comparative example 1 and the testing apparatus 100 of the present invention is that the lower end surface of the first electrode 12 protrudes from the first fixing block 112 of the first insulating member 11, and the lower end surface and at least a part of the side surface of the first electrode contact the electrolyte during testing; the upper end surface of the second electrode 22 protrudes from the bottom wall of the hopper 2121, and during the test, the upper end surface and at least part of the side surface of the second electrode 22 contact the electrolyte, and the test result of the comparative example 1 is shown in fig. 9.

The difference between the comparative example 2 and the testing apparatus 100 of the present invention is that, in addition to the difference between the comparative example 1, the protrusion 222 and the electrode body 221 are further constructed as a separate structure, and the test result of the comparative example 2 is shown in fig. 10.

Illustratively, a lithium ion battery separator 200 having a thickness of 7 μm was tested, the separator 200 was cut into a circular piece having a diameter of 20mm using a circular punch, the circular piece of separator 200, the first mold 10 and the second mold 20 of the test apparatus 100 were baked in a vacuum oven at 60 ℃ for 6h, and hermetically transferred to a glove box.

In the glove box, 1 layer of diaphragm 200 wafer is put in a flat stock bin 2121, 0.5mL of electrolyte is dripped into the glove box, the glove box is covered into a first die 10, a fastener 30 is screwed, a first conducting strip 14 and a second conducting strip 23 are connected with an electrochemical workstation, a first resistance value is tested at the test environment temperature of 25 +/-2 ℃, after the test is finished, the diaphragm 200 is taken out, the electrolyte is poured out, and the first die 10 and a second die 20 are cleaned and dried.

The above steps are repeated without placing the diaphragm 200, and a second resistance value is tested.

Calculate 1-layer diaphragm 200 resistance R1= R-R0. Three samples were tested in duplicate, labeled R1-1, R1-2, R1-3;

repeat test 2-layer separator 200 impedance signature: r2-1, R2-2 and R2-3;

repeat testing 3 layers of the membrane 200 impedance signature; r3-1, R3-2 and R3-3.

Comparative example 1 and comparative example 2 were tested in duplicate and fig. 8, 9 and 10 were made for comparison, respectively, with the following results:

through comparing the utility model discloses with comparative example 1, the impedance trend of comparative example 2 can know: the consistency of the impedance of the diaphragm 200 is affected by the capacitance interference existing when the side surface of the electrode contacts the electrolyte; the split structure of the second electrode 22 of comparative example 2 allows a new capacitance to be formed between the two portions of the second electrode 22, and the capacitive interference may further cause fluctuations in impedance.

From the above data, it can be seen that wrapping the electrodes in the insulator only exposes the opposite sides of the electrodes can eliminate the capacitive interference on the sides of the electrodes and improve the accuracy and consistency of the impedance of the separator 200.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, "the first feature" and "the second feature" may include one or more of the features.

In the description of the present invention, "a plurality" means two or more.

In the description of the present invention, the first feature "on" or "under" the second feature may include the first and second features being in direct contact, and may also include the first and second features being in contact with each other not directly but through another feature therebetween.

In the description of the invention, the first feature being "on", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. A testing device for a membrane, comprising:

a first die (10), the first die (10) comprising: a first insulating member (11) and a first electrode (12);

a second die (20), the second die (20) comprising: a second insulator (21) and a second electrode (22), the first electrode (12) being directly opposite the second electrode (22); wherein

The second insulating piece (21) is provided with a bin (2121), the first insulating piece (11) covers the side face of the first electrode (12), the second insulating piece (21) covers the side face of the second electrode (22), so that only the end faces of the first electrode (12) and the second electrode (22) are exposed out of the bin (2121), the diaphragm is arranged in the bin (2121), and the first insulating piece (11) is suitable for extending into the bin (2121) and pressing against the diaphragm.

2. The testing device for membranes according to claim 1, characterized in that said first insulator (11) comprises: the first plate body (111) and the first fixed block (112) arranged on one side, facing the second die (20), of the first plate body (111), the first plate body (111) is connected with the second insulating piece (21), and the first fixed block (112) is suitable for extending into the stock bin (2121).

3. The testing device for the separator according to claim 2, wherein a receiving groove (1121) is formed in the first fixing block (112), the first electrode (12) is disposed in the receiving groove (1121) such that an end surface of the first electrode (12) is exposed to the bin (2121), and the end surface of the first electrode (12) is located above the end surface of the first fixing block (112) to form a first groove (c).

4. The testing device for the diaphragm according to claim 3, wherein the first fixing block (112) is further provided with a mounting hole (1122) communicated with the accommodating groove (1121), the other end of the first electrode (12) is provided with a mounting part (121), and the mounting part (13) penetrates through the mounting hole (1122) and is connected with the mounting part (121).

5. The testing device for membranes according to claim 4, characterized in that a first conductive sheet (14) is provided on the mounting member (13), said first conductive sheet (14) being intended to be connected to an electrochemical workstation.

6. Testing device for membranes according to claim 1, characterized in that said second insulating member (21) comprises: the insulation board comprises a second board body (211) and a second fixing block (212), wherein the second board body (211) is connected with the first insulation part (11), and the second fixing block (212) is provided with the stock bin (2121).

7. The testing device for a separator according to claim 6, wherein the second fixing block (212) further has a mounting groove (2122) communicating with the magazine (2121), the second electrode (22) extends into the mounting groove (2122) such that an end surface of the second electrode (22) is exposed to the magazine (2121), and the end surface of the second electrode (22) is located below a bottom wall of the magazine (2121) to form a second groove (d).

8. Testing device for membranes according to claim 6, characterized in that the magazine (2121) comprises: the inner diameter of the first bin section (21211) is gradually reduced, the inner diameter of the first bin section (21211) is larger than the outer diameter of a first fixing block (112) of the first insulating piece (11), and a first overflow groove (a) is defined between the first fixing block (112) and the second bin section (21212).

9. The testing device for membranes according to claim 8, characterized in that the end of the first fixed block (112) facing the second insulator (21) is provided with a chamfer defining a second overflow channel (b) with the second bin section (21212).

10. Testing device for membranes according to claim 7, characterized in that the second electrode (22) comprises: the electrode comprises an electrode body (221) and a protruding part (222), wherein the protruding part (222) extends into the mounting groove (2122), and the electrode body (221), the second plate body (211) and the first insulating piece (11) are connected through a fastener (30).

11. The testing device for membranes according to claim 10, wherein a second conductive sheet (23) is provided on the electrode body (221), the second conductive sheet (23) being adapted to be connected to an electrochemical workstation.

12. Testing device for membranes according to any of claims 1-11, characterized in that a seal (40) is further provided between the first die (10) and the second die (20).

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