A sealed quartz crystal microbalance for lithium-ion battery electrode material testing

Abstract

The invention discloses a closed quartz crystal microbalance for detecting electrode materials of lithium ion batteries, wherein a PCB board is fixed in a receiving groove, a USB interface is fixed at the bottom of the PCB board, a chip placement groove is provided at the top of the detection pool, a QCM chip is provided in the chip placement groove, a first retractable copper column is fixed in a first jack, and one end of the first retractable copper column is fixedly connected to the PCB board, and the other end of the first retractable copper column abuts the QCM chip; a reaction groove is provided in the center of the fixed pool, and a lithium belt is provided in the reaction groove; a card block is fixed at the bottom of the end cover, and the card block is plugged and matched with the reaction groove, a circuit lead-out groove is also provided at the top of the end cover, a second retractable copper column is fixed in the second jack, one end of the second retractable copper column abuts the lithium belt, and the other end of the second retractable copper column extends into the circuit lead-out groove. The device has good airtightness, can prevent the electrode material from being oxidized during the detection process, so that the device can be measured and analyzed outside the glove box, has low environmental requirements, and is easy to carry.

Description

Technical Field

[0001] The present invention relates to the field of sensing detection technology devices, and more specifically, to a closed quartz crystal microbalance for detecting lithium ion battery electrode materials. Background Art

[0002] Quartz Crystal Microbalance (QCM) is a very sensitive mass detection instrument that can be used in liquids and gases. Its measurement accuracy can reach the nanogram level, which is 1000 times higher than the electronic microbalance with microgram sensitivity. Theoretically, the mass change measured is equivalent to a fraction of a monomolecular layer or atomic layer. It is widely used in chemistry, physics, biology, medicine, surface science and other fields.

[0003] At present, conventional electrochemical quartz crystal microbalance (EQCM) detection cells use three-electrode detection, resulting in weak overall airtightness. Therefore, it is generally necessary to put the EQCM detection cell and the detection module as a whole into a glove box for closed detection to prevent interference from the external environment. Due to the working principle of lithium ions, the positive and negative electrodes need to be separated to prevent short circuits. Therefore, conventional EQCM detection cells cannot be directly used for lithium-ion battery detection. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing EQCM detection cell has a weak overall airtightness and cannot be directly used for lithium-ion battery detection. In order to overcome the defects of the prior art, the present invention proposes a sealed quartz crystal microbalance for lithium-ion battery electrode material detection, which has good airtightness and can prevent the electrode material from being oxidized during the detection process, so that the device can be measured and analyzed outside the glove box, has low environmental requirements, and is easy to carry.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A sealed quartz crystal microbalance for detecting electrode materials of lithium-ion batteries, comprising a base, a detection cell, a fixing cell and an end cover stacked in sequence from bottom to top;

[0007] A receiving groove is provided at the bottom of the detection pool, a PCB board is fixedly arranged in the receiving groove, a USB interface is fixedly arranged at the bottom of the PCB board, a chip placement groove is provided at the top of the detection pool, and the chip placement groove is connected with the receiving groove through a first plug hole, a QCM chip is arranged in the chip placement groove, a first retractable copper column is fixedly arranged in the first plug hole, and one end of the first retractable copper column is fixedly connected to the PCB board, and the other end of the first retractable copper column is in contact with the QCM chip;

[0008] A reaction tank is provided in the center of the fixed pool, the lithium belt is arranged in the reaction tank, and a through hole is provided below the reaction tank;

[0009] A card block is fixedly provided at the bottom of the end cover, and the card block is plugged into and matched with the reaction tank. A second jack is provided on the card block. A circuit lead-out slot is also provided at the top of the end cover, and the second jack is connected to the circuit lead-out slot. A second retractable copper column is fixedly provided in the second jack, one end of the second retractable copper column is in contact with the lithium belt, and the other end of the second retractable copper column extends into the circuit lead-out slot.

[0010] In a preferred technical solution of the present invention, the detection pool, the fixing pool and the end cover are each provided with more than two magnetic holes, and magnetic columns are fixed in the magnetic holes.

[0011] In a preferred technical solution of the present invention, two half-ring sealing rings are symmetrically arranged at the bottom of the chip placement groove, and two ends of the half-ring sealing rings are respectively abutted against one of the first retractable copper pillars.

[0012] In a preferred technical solution of the present invention, a first annular groove is further provided at the bottom of the fixing pool, and a first sealing ring is fixed in the first annular groove.

[0013] In a preferred technical solution of the present invention, a second annular groove is formed on the clamping block, a second sealing ring is fixed in the second annular groove, and the second sealing ring abuts against the lithium belt.

[0014] In a preferred technical solution of the present invention, bolt holes are provided on the base, the detection pool, the fixing pool and the end cover, and fastening bolts are provided in the bolt holes.

[0015] The beneficial effects of the present invention are:

[0016] 1. The sealed quartz crystal microbalance for lithium-ion battery electrode material detection proposed in the present invention has good airtightness and can prevent the electrode material from being oxidized during the detection process, so that the device can be measured and analyzed outside the glove box, has low environmental requirements, and is easy to carry.

[0017] 2. Since the size of the through hole of the fixed cell is the contact reaction area between the electrolyte and the lithium strip, the contact area can be controlled by changing the diameter of the through hole of the fixed cell.

[0018] 3. This device is equipped with a semi-ring seal between the QCM chip and the bottom wall of the chip placement groove. When the fixing pool and the detection pool are squeezed together, the semi-ring seal can not only provide stable support for the QCM chip to ensure that the bottom of the QCM chip will not be suspended, but also ensure full contact between the retractable copper column and the QCM chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the assembly structure of a closed quartz crystal microbalance for detecting lithium-ion battery electrode materials provided by a specific embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Schematic diagram of the structure of the detection pool;

[0021] Figure 3 yes Figure 1 Schematic diagram of the structure of the fixed pool;

[0022] Figure 4 yes Figure 1 Schematic diagram of the structure of the middle end cover.

[0023] In the figure:

[0024] 1. Base; 2. Detection pool; 21. Receiving groove; 22. Chip placement groove; 23. First plug hole; 3. Fixing pool; 31. Reaction tank; 32. Through hole; 33. First annular groove; 4. End cover; 41. Circuit lead-out groove; 5. PCB board; 6. USB interface; 7. QCM chip; 8. First retractable copper column; 9. Lithium belt; 10. Card block; 101. Second plug hole; 102. Second annular groove; 11. Second retractable copper column; 12. Magnetic hole; 13. Magnetic column; 14. Semi-ring sealing ring; 15. First sealing ring; 16. Second sealing ring; 17. Bolt hole. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0026] Example

[0027] See also Figure 1-4 The sealed quartz crystal microbalance for lithium-ion battery electrode material detection provided in this embodiment includes a base 1, a detection cell 2, a fixing cell 3 and an end cover 4 stacked in sequence from bottom to top;

[0028] A receiving groove 21 is provided at the bottom of the detection pool 2, a PCB board 5 is fixedly arranged in the receiving groove 21, a USB interface 6 is fixedly arranged at the bottom of the PCB board 5, a chip placement groove 22 is provided at the top of the detection pool 2, and the chip placement groove 22 is communicated with the receiving groove 21 through a first plug hole 23, a QCM chip 7 is arranged in the chip placement groove 22, a first retractable copper column 8 is fixedly arranged in the first plug hole 23, and one end of the first retractable copper column 8 is fixedly connected to the PCB board 5, and the other end of the first retractable copper column 8 is in contact with the QCM chip 7;

[0029] A reaction tank 31 is provided at the center of the fixed pool 3, the lithium belt 9 is arranged in the reaction tank 31, and a through hole 32 is provided below the reaction tank 31;

[0030] A card block 10 is fixedly provided at the bottom of the end cover 4, and the card block 10 is plugged into and matched with the reaction tank 31. A second jack 101 is provided on the card block 10. A circuit lead-out slot 41 is also provided at the top of the end cover 4, and the second jack 101 is connected to the circuit lead-out slot 41. A second retractable copper column 11 is fixedly provided in the second jack 101, one end of the second retractable copper column 11 is in contact with the lithium belt 9, and the other end of the second retractable copper column 11 extends into the circuit lead-out slot 41.

[0031] In this embodiment, the base 1, the detection cell 2, the fixed cell 3 and the end cap 4 are all made of tetrafluoroethylene material, and the assembly process of the entire device must be carried out in a glove box. Since the glove box is a closed structure, it can isolate oxygen and prevent external impurities from entering the interior of the device; at the same time, the electrolyte is injected into the through hole 32 during the device assembly process. The base 1 is a rectangular base, and the detection cell 2 is installed on the base 1, which can close the opening of the receiving groove 21. The PCB board 5 is fixed in the receiving groove 21 by bolts, which is easy to install, and the USB interface 6 is connected to the internal circuit of the PCB board 5. The USB interface 6 is used to connect the working electrode of the external electrochemical device for detection. The QCM chip 7 is composed of a thin quartz sheet sandwiched between a pair of electrodes. By applying an AC voltage, the chip can be excited and oscillate at a unique resonant frequency, where the resonant frequency depends on the total mass of the chip and the adhesive layer on the chip surface. The chip placement groove 22 is a circular groove, and the QCM chip 7 is also a circular structure, and the diameter of the QCM chip 7 is smaller than the diameter of the chip placement groove 22. The first retractable copper column 8 and the first jack 23 are interference fit, so that elastic pressure is generated between the surfaces of the first retractable copper column 8, thereby obtaining a tight connection, and the retractable end of the first retractable copper column 8 is in contact with the metal layer at the bottom of the QCM chip 7. The fixed pool 3 and the end cover 4 are both cylindrical structures, and the fixed pool 3 and the end cover 4 are coaxially arranged. The through hole 32 is located at the center of the fixed pool 3, and the through hole 32 is connected to the reaction tank 31. The electrolyte can be injected into the through hole 32 through the reaction tank 31, wherein the cross-sectional area of ​​the through hole 32 is the contact reaction area of ​​the lithium strip 9. The contact area can be controlled by controlling the aperture size of the through hole 32. In addition, when injecting the liquid, it is necessary to pay attention to the liquid level of the electrolyte should be in contact with the lower surface of the lithium strip 9, but not exceeding the upper surface of the lithium strip 9. The block 10 is matched with the reaction tank 31, and the height of the block 10 is smaller than the depth of the reaction tank 31, so that the bottom surface of the end cover 4 is closely abutted against the end surface of the fixed pool 3, thereby closing the reaction tank 31. The second retractable copper column 11 and the second jack 101 also adopt interference fit, the retractable end of the second retractable copper column 11 is in contact with the top of the lithium belt 9, and the non-retractable end of the second retractable copper column 11 is located in the circuit lead-out groove 41, which is used to connect the counter electrode and the reference electrode of the electrochemical device, wherein the first retractable copper column 8 and the second retractable copper column 11 are both provided with two.

[0032] Specifically, the detection pool 2 , the fixing pool 3 and the end cover 4 are each provided with more than two magnetic holes 12 , and magnetic columns 13 are fixedly disposed in the magnetic holes 12 .

[0033] In this embodiment, the magnetic column 13 is used to perform preliminary positioning of the fixed pool 3 and the end cover 4 during the installation process, which helps to increase the installation speed.

[0034] Specifically, two half-ring sealing rings 14 are symmetrically arranged at the bottom of the chip placement groove 22 , and two ends of the half-ring sealing ring 14 are respectively abutted against one of the first retractable copper pillars 8 .

[0035] In this embodiment, the semi-ring sealing ring 14 has high elasticity and is arranged at the bottom of the chip placement groove 22. When the device cooperates to squeeze the QCM chip 7, the bottom will not be suspended in the air. It can not only play a role of stable support, but also ensure that the first retractable copper column 8 is in full contact with the QCM chip 7.

[0036] Specifically, a first annular groove 33 is further formed at the bottom of the fixing pool 3 , and the first sealing ring 15 is fixedly disposed in the first annular groove 33 .

[0037] In this embodiment, by providing the first sealing ring 15, the fixing pool 3 and the detection pool 2 will squeeze the first sealing ring 15 after being fixed together, so as to seal the contact part between the through hole 32 and the QCM chip 7, thereby preventing leakage of the electrolyte in the through hole 32. In addition, by providing the first sealing ring 15, the QCM chip 7 can be prevented from rigidly contacting the bottom end surface of the fixing pool 3, thereby protecting the QCM chip 7.

[0038] Specifically, the clamping block 10 is provided with a second annular groove 102 , the second sealing ring 16 is fixedly disposed in the second annular groove 102 , and the second sealing ring 16 abuts against the lithium belt 9 .

[0039] In this embodiment, by providing the second sealing ring 16 , the lithium ribbon 9 can be squeezed to ensure that the lower surface of the lithium ribbon 9 is in full contact with the electrolyte.

[0040] Specifically, bolt holes 17 are provided on the base 1 , the detection pool 2 , the fixing pool 3 and the end cover 4 , and fastening bolts are provided in the bolt holes 17 .

[0041] In this embodiment, after the magnetic column 13 has positioned the fixing pool 3 and the end cover 4, the fixing can be completed by using fastening bolts, which is easy to operate.

[0042] When in use, the first step is to complete the assembly of the device in the glove box;

[0043] Step 2: Move the assembled device outside the box and connect it to the electrochemical device for direct detection, wherein the USB port is connected to the working electrode of the electrochemical device, and the second retractable copper column is connected to the counter electrode and the reference electrode;

[0044] Step 3: Detect through in-situ analysis and perform data processing.

[0045] The device provided by the present invention has good airtightness and can prevent the electrode material from being oxidized during the detection process, so that the device can be measured and analyzed outside the glove box, has low environmental requirements, and is easy to carry.

[0046] The present invention is described by preferred embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. The present invention is not limited to the specific embodiments disclosed herein, and other embodiments falling within the claims of this application are within the scope of protection of the present invention.

Claims

1. A sealed quartz crystal microbalance for detecting electrode materials of lithium-ion batteries, comprising a base (1), a detection cell (2), a fixing cell (3) and an end cover (4) stacked in sequence from bottom to top, characterized in that: A receiving groove (21) is provided at the bottom of the detection pool (2), a PCB board (5) is fixedly arranged in the receiving groove (21), a USB interface (6) is fixedly arranged at the bottom of the PCB board (5), a chip placement groove (22) is provided at the top of the detection pool (2), and the chip placement groove (22) is connected to the receiving groove (21) through a first plug hole (23), a QCM chip (7) is arranged in the chip placement groove (22), a first retractable copper column (8) is fixedly arranged in the first plug hole (23), one end of the first retractable copper column (8) is fixedly connected to the PCB board (5), and the other end of the first retractable copper column (8) is in contact with the QCM chip (7); Two half-ring sealing rings (14) are symmetrically arranged at the bottom of the chip placement groove (22), and the two ends of the half-ring sealing ring (14) are respectively in contact with one of the first retractable copper pillars (8); A reaction tank (31) is provided at the center of the fixed pool (3), the lithium belt (9) is arranged in the reaction tank (31), and a through hole (32) is provided below the reaction tank (31); A card block (10) is fixedly provided at the bottom of the end cover (4), and the card block (10) is plugged into and matched with the reaction tank (31); a second plug hole (101) is provided on the card block (10); a circuit lead-out slot (41) is also provided on the top of the end cover (4), and the second plug hole (101) is communicated with the circuit lead-out slot (41); a second retractable copper column (11) is fixedly provided in the second plug hole (101), one end of the second retractable copper column (11) is in contact with the lithium belt (9), and the other end of the second retractable copper column (11) extends into the circuit lead-out slot (41); Two first retractable copper columns (8) are provided.

2. The sealed quartz crystal microbalance for detecting lithium-ion battery electrode materials according to claim 1, characterized in that: The detection pool (2), the fixing pool (3) and the end cover (4) are each provided with more than two magnetic holes (12), and a magnetic column (13) is fixedly disposed in the magnetic hole (12).

3. The sealed quartz crystal microbalance for detecting lithium-ion battery electrode materials according to claim 1, characterized in that: The bottom of the fixing pool (3) is also provided with a first annular groove (33), and the first sealing ring (15) is fixedly arranged in the first annular groove (33).

4. The sealed quartz crystal microbalance for detecting lithium-ion battery electrode materials according to claim 1, characterized in that: The block (10) is provided with a second annular groove (102), the second sealing ring (16) is fixedly arranged in the second annular groove (102), and the second sealing ring (16) is in contact with the lithium belt (9).

5. The sealed quartz crystal microbalance for detecting lithium-ion battery electrode materials according to claim 1, characterized in that: The base (1), the detection pool (2), the fixing pool (3) and the end cover (4) are all provided with bolt holes (17), and fastening bolts are arranged in the bolt holes (17).

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