CN209979116U

CN209979116U - Lithium battery gas full-collecting and internal pressure testing device

Info

Publication number: CN209979116U
Application number: CN201920995796.7U
Authority: CN
Inventors: 陈丹丹; 杨伟; 李立飞; 郑杰允; 王德宇; 王其钰
Original assignee: Institute of Physics of CAS; Tianmu Lake Institute of Advanced Energy Storage Technologies Co Ltd
Current assignee: Institute of Physics of CAS; Tianmu Lake Institute of Advanced Energy Storage Technologies Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-01-21
Anticipated expiration: 2029-06-28

Abstract

The utility model provides a device for fully collecting lithium battery gas and testing internal pressure, which comprises a fixing mechanism, a gas collecting mechanism and a puncture mechanism; the fixing mechanism comprises an upper shell and a lower shell, and the upper shell and the lower shell can mutually enclose to form a cavity for accommodating the battery to be tested; the cavity is connected with a gas collecting mechanism, the gas collecting mechanism sequentially comprises a first gas collecting bag, a second gas collecting bag and a second vacuum pump, the cavity is also connected with the first vacuum pump through a pipeline, and a gas output channel of the first vacuum pump is communicated with the first gas collecting bag; valves are arranged on the communicating pipelines of the sections of the gas collecting mechanism; the puncturing mechanism is provided with a drill bit and a drill rod, the drill rod extends into the fixing mechanism from the outside of the fixing mechanism, the drill bit is connected with the inside of the fixing mechanism, and the drill bit can penetrate into the cavity under the driving of the drill rod. The utility model discloses a device can realize cylinder type lithium cell inside gas and collect, detect and the control of internal pressure entirely.

Description

Lithium battery gas full-collecting and internal pressure testing device

Technical Field

The utility model relates to a lithium ion battery detects technical field, especially relates to a gaseous full collection of cylindrical lithium ion battery and internal pressure detection device.

Background

Lithium ion batteries are relatively ideal energy storage devices due to their advantages of high energy density, high power density, low self-discharge rate, etc., and have been widely used in the fields of consumer electronics, electric tools, electric vehicles, etc. However, during the use of the lithium ion battery from the initial formation to the later stage, a redox side reaction is always generated, so that a certain amount of gas is inevitably generated, the internal pressure of the battery is increased, the battery can be cracked when the pressure reaches a certain degree, and liquid leakage, fire and even explosion are caused, and the safety of the battery is affected. Therefore, the generated gas needs to be qualitatively and quantitatively analyzed, the reason of the gas generation is analyzed, and the gas generation problem is improved or solved from the source. And the method has important guiding significance for detecting the internal pressure of the lithium ion battery and deducing the reaction condition of the battery.

The existing gas taking method is generally a water drainage and gas collection method, a battery is dissected under water, and discharged gas is collected through a gas collection pipe with scales and water. This method is inconvenient to operate, poor in accuracy and reproducibility, and poor in safety. In the battery internal gas measuring device, a battery internal gas taking device is disclosed, but in the invention, a gas collecting device is communicated with air, so that the gas collecting device cannot be used for gas component analysis. The gas extraction methods in most patents can only extract a part of gas in the lithium battery, and quantitative analysis can not be carried out on the gas.

Disclosure of Invention

The utility model aims at providing a safe swift, easy operation's lithium ion battery gas collection and internal pressure test's device to realize cylinder type lithium cell inside gas and collect, detect and internal pressure's monitoring device entirely.

In order to achieve the above purpose, the utility model discloses an adopt following technical scheme:

a device for fully collecting gas and testing internal pressure of a lithium battery comprises a fixing mechanism, a gas collecting mechanism and a puncturing mechanism; the fixing mechanism comprises an upper shell and a lower shell, and the upper shell and the lower shell can mutually enclose to form a cavity for accommodating a battery to be tested; the cavity is connected with a gas collecting mechanism through a pipeline, the gas collecting mechanism comprises a first gas collecting bag, a second gas collecting bag and a second vacuum pump which are sequentially communicated with the cavity, the cavity is also connected with the first vacuum pump through a pipeline, and a gas output channel of the first vacuum pump is communicated with the first gas collecting bag; valves are arranged on the communicating pipelines of the sections of the gas collecting mechanism; the puncturing mechanism is provided with a drill bit and a drill rod, the drill rod extends into the fixing mechanism from the outside of the fixing mechanism, the drill bit is connected with the inside of the fixing mechanism, and the drill bit can penetrate into the cavity under the driving of the drill rod.

The connecting part of the upper shell and the lower shell is provided with a first sealing gasket, the upper shell and the lower shell can be fixedly connected through a connecting fastener, and the connecting fastener is a connecting flange or a threaded fastener.

The upper shell is provided with a convex body part used for connecting the puncture mechanism, the top of the convex body part is detachably connected with a cover body, and a second sealing gasket is arranged at the connecting part between the cover body and the convex body part; the drill rod penetrates into the fixing mechanism through the cover body, threads which can be meshed with each other are arranged on the outer surface of the drill rod and the cover body, and a handle is arranged on the drill rod outside the fixing mechanism; the convex part is provided with a space capable of accommodating a drill bit; the cover body is connected with the convex body part in a threaded connection or a clamping connection mode.

And a compression spring is arranged on the inner wall of the enclosed cavity of the upper shell and/or the lower shell.

The drill bit top opening and inside are equipped with pressure sensor, pressure sensor and outside pressure measurement device signal connection, pressure measurement device includes digital display.

The valve on each section of communicating pipe of the gas collecting mechanism comprises: a first valve on a communication channel of the cavity and the first air collecting bag, a second valve on a communication channel of the first air collecting bag and the second air collecting bag, a third valve on a communication channel of the second air collecting bag and the second vacuum pump, a fourth valve on a communication channel of the cavity and the first vacuum pump, and a fifth valve on a communication channel of the first vacuum pump and the first air collecting bag, wherein all the valves are one-way valves; each section of communicating pipeline of the gas collecting mechanism is a rubber hose.

The first gas collecting bag and the second gas collecting bag are both aluminum foil sampling bags; and sampling ports are arranged on the first air collecting bag and the second air collecting bag.

The utility model discloses the beneficial effect who produces is: the device of the utility model is simple in structure, safe swift, can carry out full collection and detect internal pressure simultaneously to the inside gas of battery, the sample can realize collecting completely and effectively realize gas-liquid separation, can carry out accurate collection and detection to the liquid sample homoenergetic of gas sample and electrolyte, has filled the blank that the aspect of lithium cell detection integration detected the technique, and specially adapted is convenient for place the detection of the small-size lithium ion battery in certain space.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

fig. 1 is a schematic structural diagram of the device of the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings, without limiting the scope of the invention.

The device for fully collecting gas and testing internal pressure of the lithium battery of the utility model is shown in figure 1 and comprises a fixing mechanism 1, a gas collecting mechanism 2 and a puncturing mechanism 3; the fixing mechanism 1 comprises an upper shell 101 and a lower shell 102, wherein the upper shell 101 and the lower shell 102 can mutually enclose to form a cavity 103 for accommodating a battery to be tested; the cavity 103 is connected with a gas collecting mechanism 2 through a pipeline, the gas collecting mechanism 2 comprises a first gas collecting bag 201, a second gas collecting bag 202 and a second vacuum pump 204 which are sequentially communicated with the cavity 103, the cavity 103 is further connected with a first vacuum pump 203 through a pipeline, and a gas output channel of the first vacuum pump 203 is communicated with the first gas collecting bag 201; valves are arranged on the communicating pipelines of the sections of the gas collecting mechanism 2; the puncturing mechanism 3 is provided with a drill bit 301 and a drill rod 302, the drill rod 302 extends into the fixing mechanism 1 from the outside, the drill bit 301 is connected with the inside of the fixing mechanism 1, and the drill bit 301 can extend into the cavity 103 under the driving of the drill rod 302.

The connecting part of the upper shell 101 and the lower shell 102 is provided with a first sealing gasket 105, the upper shell 101 and the lower shell 102 can be fixedly connected through a connecting fastener 104, the first sealing gasket 105 is fastened and attached to seal the upper shell and the lower shell during fixed connection, the connecting fastener 104 can be in various implementation forms, and conventional implementation means such as a connecting flange or a threaded fastener are adopted in the prior art.

The upper shell 101 is provided with a convex body 106 for connecting the puncture mechanism 3, the top of the convex body 106 is detachably connected with a cover body 107, and a second sealing gasket 108 is arranged at the connecting part between the cover body 107 and the convex body 106; the drill rod 302 goes deep into the fixing mechanism 1 through the cover body 107, threads which can be meshed with each other are arranged on the outer surface of the drill rod 302 and the cover body 107, a handle 303 is arranged on the drill rod 302 outside the fixing mechanism 1, the drill rod 302 is driven to rotate through the rotating handle 303, the drill rod 302 can drive the drill bit 301 to lift under the meshing action of the threads, and when the drill rod is continuously lowered, acting force can be applied to a battery to be tested which is placed in the fixing mechanism 1, so that the battery can be punctured; the convex portion 106 has a space capable of accommodating the drill 301 for placing the drill 301 when the piercing operation is not performed; the cover 107 may be connected to the boss 106 by various means, such as a screw connection, a snap connection, etc., which are conventional in the art.

The inner wall of the cavity 103 enclosed by the upper shell 101 and/or the lower shell 102 can be provided with a compression spring 109 for compressing and positioning the battery to be tested placed in the cavity 103 and preventing the battery from shaking.

The top of the drill bit 301 is open and has a pressure sensor (not shown) inside, the pressure sensor is in signal connection with an external pressure detection device, the pressure detection device is used for processing, displaying, recording or feeding back the obtained pressure information, for example, the pressure detection device has a digital display, and the measured pressure can be displayed. The pressure sensor and the pressure detection device belong to conventional devices in the prior art and can be directly obtained on the market.

The valve on each section of communicating pipeline of the gas collecting mechanism 2 comprises: the first valve 205 on the communication channel between the cavity 103 and the first gas collecting bag 201, the second valve 206 on the communication channel between the first gas collecting bag 201 and the second gas collecting bag 202, the third valve 207 on the communication channel between the second gas collecting bag 202 and the second vacuum pump 204, the fourth valve 208 on the communication channel between the cavity 103 and the first vacuum pump 203, and the fifth valve 209 on the communication channel between the first vacuum pump 203 and the first gas collecting bag 201 are all one-way valves, and thus gas backflow can be effectively prevented. Each section of the communicating pipeline of the gas collecting mechanism 2 is preferably a rubber hose, so that the installation is convenient, and the joint can be sealed by glue liquid so as to avoid the interference of outside air and the leakage of gas.

The first air collecting bag 201 and the second air collecting bag 202 are both aluminum foil sampling bags, so that the volume is small, and the sealing performance is good; the first air collecting bag 201 and the second air collecting bag 202 are both provided with sampling ports 210, the sampling ports 210 can be directly connected with an external detection device through sampling pipes and the like, sampling can also be performed through the sampling ports 210 through an independent sampling device, the specific structural design of the sampling ports 210 has various implementation forms in the conventional technology, and the scheme can be realized by adopting the existing design.

Adopt the utility model discloses when the device carries out the gaseous and electrolyte collection of lithium cell and analysis, concrete operation includes following step: the battery to be tested is placed in the cavity 103 and pressed by the pressing spring 109, and the upper casing 101 and the lower casing 102 are fixedly connected by the connecting fastener 104. Before the device runs, all valves are opened, the second vacuum pump 204 is used for vacuumizing the device, and after the vacuumizing is finished, the valves except the first valve 205 are closed. The drill bit 301 moves downwards by rotating the handle 303 and punctures the battery to be tested, when the battery punctures, gas rushes into the drill bit 301 through the top opening of the drill bit 301 and passes through the pressure sensor, the pressure value at the moment is obtained through the pressure sensor, and the pressure value can be read through the pressure value on the digital display, namely the internal pressure of the battery. Since the inside of the device is at a negative pressure, the internal pressure of the battery is higher than the outside, the gas inside the battery is discharged and enters the first gas collecting bag 201, and the discharged gas comprises the conventional reaction gas inside the battery (and also comprises the gas obtained by partially vaporizing the electrolyte). When the pressure is equalized, the gas stops entering the first gas collecting bag 201. And (3) closing the first valve 205, opening the fourth valve 208 and the fifth valve 209, further vacuumizing the cavity 103 by using the first vacuum pump 203, allowing the residual gas in the battery and in the cavity 103 to enter the first gas collecting bag 201, and taking out the gas in the battery completely when the gas amount in the first gas collecting bag 201 does not change or the value displayed by the vacuum pump does not change, and closing the first vacuum pump 203, the fourth valve 208 and the fifth valve 209. The first gas collecting bag 201 and the second gas collecting bag 202 are placed at a low temperature for a period of time, after the electrolyte vaporized in the gas is liquefied into liquid, the second valve 206 is opened, so that the non-liquefied gas enters the second gas collecting bag 202, and the electrolyte still stays in the first gas collecting bag 201, thereby realizing gas-liquid separation. Gas analysis and electrolyte analysis can be performed separately by using a sampler to collect gas and liquid separately.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for full gas collection and internal pressure test of a lithium battery comprises a fixing mechanism (1), a gas collecting mechanism (2) and a puncturing mechanism (3); the fixing mechanism (1) comprises an upper shell (101) and a lower shell (102), wherein the upper shell (101) and the lower shell (102) can mutually enclose to form a cavity (103) for accommodating a battery to be tested; the cavity (103) is connected with a gas collecting mechanism (2) through a pipeline, the gas collecting mechanism (2) comprises a first gas collecting bag (201), a second gas collecting bag (202) and a second vacuum pump (204) which are sequentially communicated with the cavity (103), the cavity (103) is also connected with a first vacuum pump (203) through a pipeline, and a gas output channel of the first vacuum pump (203) is communicated with the first gas collecting bag (201); valves are arranged on the communicating pipelines of the sections of the gas collecting mechanism (2); the puncture mechanism (3) is provided with a drill bit (301) and a drill rod (302), the drill rod (302) extends into the fixing mechanism (1) from the outside, the drill bit (301) is connected with the inside of the fixing mechanism (1), and the drill bit (301) can be driven by the drill rod (302) to penetrate into the cavity (103).

2. The lithium battery gas full collection and internal pressure test device according to claim 1, wherein a first sealing gasket (105) is arranged at the connection part of the upper casing (101) and the lower casing (102), the upper casing (101) and the lower casing (102) can be fixedly connected through a connection fastener (104), and the connection fastener (104) is a connection flange or a threaded fastener.

3. The lithium battery gas full collection and internal pressure test device according to claim 1, wherein a convex part (106) for connecting the puncture mechanism (3) is arranged on the upper shell (101), a cover body (107) is detachably connected to the top of the convex part (106), and a second sealing gasket (108) is arranged at the connecting part between the cover body (107) and the convex part (106); the drill rod (302) penetrates into the fixing mechanism (1) through the cover body (107), threads which can be meshed with each other are arranged on the outer surface of the drill rod (302) and the cover body (107), and a handle (303) is arranged on the drill rod (302) outside the fixing mechanism (1); the convex portion (106) has a space capable of accommodating a drill bit (301); the cover body (107) and the convex part (106) are in threaded connection or clamping connection.

4. The lithium battery gas full collecting and internal pressure testing device according to claim 1, characterized in that the inner wall of the enclosed cavity (103) of the upper shell (101) and/or the lower shell (102) is provided with a compression spring (109).

5. The lithium battery gas full collection and internal pressure test device according to claim 1, wherein the drill bit (301) is open at the top and has a pressure sensor inside, the pressure sensor is in signal connection with an external pressure detection device, and the pressure detection device comprises a digital display.

6. The lithium battery gas full collection and internal pressure test device according to claim 1, wherein the valves on the connecting pipelines of the gas collection mechanism (2) comprise: a first valve (205) on a communication channel between the cavity (103) and the first air collecting bag (201), a second valve (206) on a communication channel between the first air collecting bag (201) and the second air collecting bag (202), a third valve (207) on a communication channel between the second air collecting bag (202) and the second vacuum pump (204), a fourth valve (208) on a communication channel between the cavity (103) and the first vacuum pump (203), and a fifth valve (209) on a communication channel between the first vacuum pump (203) and the first air collecting bag (201), wherein all the valves are one-way valves; each section of the communicating pipeline of the gas collecting mechanism (2) is a rubber hose.

7. The lithium battery gas full collection and internal pressure test device according to claim 1, wherein the first gas collection bag (201) and the second gas collection bag (202) are both aluminum foil sampling bags; the first air collecting bag (201) and the second air collecting bag (202) are both provided with sampling ports (210).