CN211905034U

CN211905034U - Device for simulating damage of particles or dendrites to diaphragm

Info

Publication number: CN211905034U
Application number: CN201922365276.0U
Authority: CN
Inventors: 陈增发; 姚坤; 王维康; 王会娜; 刘琳
Original assignee: Shenzhen Zhongxing New Material Technology Co ltd
Current assignee: Shenzhen Zhongxing New Material Technology Co ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-11-10
Anticipated expiration: 2029-12-25

Abstract

The application discloses a device for simulating the damage of particles or dendrites to a diaphragm. The device comprises a micro press, a spine die and a power supply; the micro press comprises a press head, a support and a base, wherein the support is arranged on the base, the micro press is supported right above the base, and the press head can be vertically moved and arranged right above the base; the surface of the spine die is provided with a plurality of micron-sized spines, the spine die is supported and mounted on the base by the die support, the spine die is mounted upwards in a spine shape, and the whole spine die is positioned right below the pressure head; the pressure head and the spine die are both made of conductive materials, and the anode and the cathode of the power supply are respectively connected with the pressure head and the spine die. The device of this application, the destruction of the particle that suffers or the dendrite in the ability simulation battery diaphragm use, not only can be more accurate effectual the anti particle of detection diaphragm and the destructiveness of dendrite performance, can be used for researching and developing resistant particle and dendrite diaphragm that destroys in addition, provides better guarantee for the security of battery.

Description

Device for simulating damage of particles or dendrites to diaphragm

Technical Field

The application relates to the field of battery diaphragm detection equipment, in particular to a device for simulating damage of particles or dendrites to a diaphragm.

Background

The diaphragm is an important component of the lithium ion battery and has great influence on the safety performance of the lithium ion battery. The primary function of the separator is to prevent shorting of the positive and negative electrodes and to allow ion transport. Theoretically, thermal runaway of the battery could be prevented by the closure of the micropores of the separator, but some recent accidents have shown that this closure is not very effective. That is, even though theoretically the micropores of the separator have closed; however, an internal short circuit still occurs, causing a short-circuit accident.

In addition to further developments to improve the closed cell performance of the septum, it is also a solution to enhance the puncture performance of the septum. However, it has been proved in practice that even if the piercing property of the separator is enhanced, the battery is still internally micro-short-circuited during use.

Disclosure of Invention

The purpose of the present application is to provide a device that simulates the damage of particles or dendrites to the membrane.

In order to achieve the purpose, the following technical scheme is adopted in the application:

the application discloses a device for simulating damage of particles or dendrites to a diaphragm, which comprises a micro press, a spine die and a power supply; the miniature press comprises a press head, a support and a base, wherein the support is arranged on the base, the whole miniature press is supported and arranged right above the base, and the press head can be vertically moved and arranged right above the base; the surface of the spine die is provided with a plurality of micron-sized spines, the spine die is supported and mounted on the base by the die support, the spine die is mounted upwards in a spine shape, and the whole spine die is positioned right below the pressure head; the pressure head and the spine die are both made of conductive materials, and the anode and the cathode of the power supply are respectively connected with the pressure head and the spine die.

It should be noted that, the research of the present application finds that even though the battery separator has a strong piercing performance, there still occurs an internal micro short circuit, and the reason is mainly two ways, first, small metal particles enter the battery during the manufacturing process, and after piercing the separator in the charge and discharge cycle, a direct short circuit path is provided between the batteries; secondly, dendrite is gradually formed inside the battery during the use process of the battery, and the battery punctures the diaphragm to cause internal micro short circuit. The particle size of these particles or dendrite spikes is typically on the order of microns, and there is currently no good method or apparatus to simulate the damage of the particles or dendrites to the membrane. Based on the above analysis and recognition, the present application has developed a new device to simulate the damage of particles or dendrites to the membrane. According to the device, on one hand, the particle size of the particle or the dendritic crystal sharp spine is simulated through the micron-sized sharp spine; on the other hand, the actual circuit service environment of the diaphragm is simulated by applying a current mode, so that the performance of the diaphragm is tested more accurately and effectively.

In addition, it can be understood that the spine mould of this application can be replaced according to the demand, for example, replace the spine mould of the not spike of equidimension spine to the damage of different spines to the diaphragm is convenient for test and comparison.

Preferably, the spine die and the die support or the die support and the base are connected by an insulating block.

The insulation block is connected to isolate the spike die from a power supply after the spike die is connected to the power supply, so that safety accidents such as short circuit or electric shock are avoided.

Preferably, a current detection device is arranged on a connecting circuit of the power supply, the pressure head and the spike die.

The current detection device is used for detecting whether or not the circuit is on and whether or not a current is generated. It is understood that the present application detects the damage of the particles or dendrites to the separator, which is the creation of internal micro-short circuits during the actual use of the battery separator; therefore, the current generated in the circuit is used for simulating the internal micro short circuit, so that the damage of the particles or the dendrites to the diaphragm is judged. In principle, the output pressure value can represent the resistance of the battery diaphragm to particles or dendrites just when the current is generated; that is, the larger the pressure value is, the better the performance of the battery separator is, and the less likely an accident of internal micro-short circuit occurs. It will be appreciated that this pressure value may or may not correlate well with the puncture strength of the battery separator.

Preferably, the current detection device is an ammeter, a voltmeter, a multimeter or a current sensor.

It is understood that the current detection device may be an ammeter, a voltmeter, a multimeter or a current sensor as long as it can detect the current in the circuit.

Preferably, a protection device is arranged on a connecting circuit of the power supply, the pressure head and the spike die.

Preferably, the protection device is a fuse.

It should be noted that the fuse of the present application is a fuse conventionally used in circuit design, and has an effect of avoiding a short circuit caused by direct contact with a pressure head after a spine die pierces a battery diaphragm.

Preferably, a resistor is arranged on a connecting circuit of the power supply, the pressure head and the spike die.

It should be noted that the design of the resistor also plays a role of protecting the circuit to a certain extent, and it can be understood that the larger the resistor in the circuit, the smaller the current, the higher the safety, and the greater the sensitivity requirement on the current detection device. The specific resistance value may be determined according to the requirement, and is not particularly limited herein.

Preferably, a power switch is arranged on a connecting circuit of the power supply, the pressure head and the spike die.

It should be noted that the power switch is used to directly disconnect the circuit, and when the power switch is not used or a micro short circuit inside the battery diaphragm is definitely detected, the power switch may be directly used to disconnect the circuit to end the test in order to avoid damage to the circuit or ensure safety.

Due to the adoption of the technical scheme, the beneficial effects of the application are as follows:

the device for simulating the damage of the particles or the dendrites to the diaphragm can simulate the damage of the particles or the dendrites suffered by the battery diaphragm in the using process, not only can the performance of the diaphragm for resisting the damage of the particles and the dendrites be detected more accurately and effectively, but also can be used for researching and developing the diaphragm resistant to the damage of the particles and the dendrites, and provides better guarantee for the safety of the battery.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for simulating the destruction of a membrane by particles or dendrites in an embodiment of the present application;

FIG. 2 is a schematic side view of a spike die of an apparatus for simulating the destruction of a membrane by particles or dendrites according to an embodiment of the present disclosure;

fig. 3 is a schematic front structural view of a spike die of a device for simulating the damage of particles or dendrites to a membrane in the embodiment of the present application.

Detailed Description

The puncture strength of the diaphragm refers to the force required by the experimental needle to puncture the diaphragm, and the characteristic can reflect the mechanical strength of the diaphragm; however, the separator having a high puncture strength still cannot avoid occurrence of internal micro short circuit. The inventor of the present application analyzes that this may be caused by two reasons: first, smaller metal particles enter the cell during the manufacturing process, piercing the separator during the charge-discharge cycle causing internal micro-shorts; second, dendrites formed inside the separator pierce the separator, causing internal micro-shorts. Both of these conditions cannot be measured by existing puncture strength tests.

Therefore, the application especially develops a device for simulating the damage of particles or dendrites to the diaphragm, namely, the device comprises a micro-press, a sharp-pointed die and a power supply; the miniature press comprises a press head, a support and a base, wherein the support is arranged on the base, the whole miniature press is supported and arranged right above the base, and the press head, namely the movable end of the miniature press, can be arranged right above the base in an up-and-down moving manner; the surface of the spine die is provided with a plurality of micron-sized spines, the spine die is supported and mounted on the base by the die support, the spine die is mounted upwards in a spine shape, and the whole spine die is positioned right below the pressure head; the pressure head and the spine die are both made of conductive materials, and the anode and the cathode of the power supply are respectively connected with the pressure head and the spine die.

The device of this application adopts miniature press to exert pressure, and the particle or the dendrite's that suffer in the use through spine mould and power simulation battery diaphragm destruction to this research is avoided the battery diaphragm to take place the tolerance of inside little short circuit, so that research and development tolerance is stronger battery diaphragm, provides better guarantee for the security of battery.

The present application is described in further detail below with reference to specific embodiments and the attached drawings. The following examples are intended to be illustrative of the present application only and should not be construed as limiting the present application.

Examples

The device for simulating the damage of the particles or the dendrites to the diaphragm comprises a micro-press 1, a sharp punch die 2 and a power supply 3, as shown in figure 1; the miniature press machine 1 comprises a press head 11, a support 12 and a base 13, wherein the support 12 is installed on the base 13, the whole miniature press machine 1 is supported and installed right above the base 13, and the press head 11 can be installed right above the base 13 in an up-and-down moving mode.

As shown in fig. 2 and 3, the spike mold 2 of this embodiment has several micron-sized spikes 21 on its surface, the spike mold 2 is supported and mounted on the base 13 by the mold support 22, the spike mold 2 is mounted upward in the form of the spikes 21, and the entire spike mold 2 is located right below the ram 11.

The pressure head 11 and the spine die 2 of the embodiment are both made of conductive materials, and the anode and the cathode of the power supply 3 are respectively connected with the pressure head 11 and the spine die 2. The mold holder 22 and the base 13 of this example are connected by an insulating block 4.

The connection circuit between the power source 3 and the indenter 11 and the spike die 2 in this example is provided with a current detection device 31, which is an ammeter in this example. The connection circuit of the power supply 3 with the ram 11 and the spike die 2 is provided with a protection device, in this example a fuse 32. A resistor 33 is arranged on a connecting circuit of the power supply 3, the pressure head 11 and the spike die 2, and the resistance value is 100 omega. A power switch 34 is provided in a connection circuit between the power source 3 and the ram 11 and the spike die 2.

When the device for simulating the damage of the particles or the dendrites to the diaphragm is used, the battery diaphragm is firstly placed on the surface of the spine die 2; the power switch 34 is then closed, putting the circuit in a connectable state; a pressure head 11 of the micro-press 1 presses downwards to simulate the damage of particles or dendrites to the diaphragm; until the ammeter detects the current, the battery diaphragm is judged to have an internal micro short circuit at the moment, and the pressure application is stopped, wherein the pressure value at the moment is the tolerance of the battery diaphragm for avoiding the internal micro short circuit; the larger the tolerance, the less likely the battery separator to be subjected to internal micro-short circuit, and the better the safety. After the tolerance of the micro short circuit in the battery diaphragm is obtained through measurement, pressure can be further applied, and the occurrence and development conditions of the micro short circuit in the battery diaphragm are judged according to the current change detected by the ammeter, so that the overall safety of the battery diaphragm is researched and evaluated. It will be appreciated that until the cell membrane has been fully pierced, the indenter 11 is in contact with the spikes 21 of the spike die 2, at which point the current is at its maximum and relatively stable. The resistor has the function of limiting the maximum current, so that the damage of the device caused by overlarge current is avoided; the fuse has the function of timely disconnecting the circuit when the current is overlarge, so that the device is protected; when the test is completed, the circuit is disconnected through the power switch 34, the micro press 1 is reset, the battery diaphragm is taken out, and the device is standby for the next test.

The foregoing is a more detailed description of the present application in connection with specific embodiments thereof, and it is not intended that the present application be limited to the specific embodiments thereof. It will be apparent to those skilled in the art from this disclosure that many more simple derivations or substitutions can be made without departing from the spirit of the disclosure.

Claims

1. A device for simulating the damage of particles or dendrites to a membrane, comprising: comprises a micro press (1), a spine die (2) and a power supply (3);

the miniature press machine (1) comprises a press head (11), a support (12) and a base (13), wherein the support (12) is arranged on the base (13), the whole miniature press machine (1) is supported and arranged right above the base (13), and the press head (11) can be vertically moved and arranged right above the base (13);

the surface of the spine die (2) is provided with a plurality of micron-sized spines (21), the spine die (2) is supported and mounted on the base (13) by a die support (22), the spine die (2) is mounted upwards in the shape of the spine (21), and the whole spine die (2) is positioned right below the pressure head (11);

the pressure head (11) and the spine die (2) are both made of conductive materials, and the positive electrode and the negative electrode of the power supply (3) are respectively connected with the pressure head (11) and the spine die (2).

2. The apparatus of claim 1, wherein: the spine die (2) is connected with the die support (22) or the die support (22) is connected with the base (13) through the insulating block (4).

3. The apparatus of claim 1, wherein: and a current detection device (31) is arranged on a connecting circuit of the power supply (3) and the pressure head (11) and the spine die (2).

4. The apparatus of claim 3, wherein: the current detection device is an ammeter, a voltmeter, a multimeter or a current sensor.

5. The apparatus of claim 1, wherein: and a protection device is arranged on a connecting circuit of the power supply (3) and the pressure head (11) and the spine die (2).

6. The apparatus of claim 5, wherein: the protection device is a fuse (32).

7. The apparatus of claim 1, wherein: and a resistor (33) is arranged on a connecting circuit of the power supply (3) and the pressure head (11) and the spine die (2).

8. The apparatus of claim 1, wherein: and a power switch (34) is arranged on a connecting circuit of the power supply (3) and the pressure head (11) and the spine die (2).