CN111929351A

CN111929351A - Double-sealing type multifunctional electrochemical testing device and assembling and using method thereof

Info

Publication number: CN111929351A
Application number: CN202010958748.8A
Authority: CN
Inventors: 卢文; 向富维; 杨晓萍
Original assignee: Kunming Yunda New Energy Co ltd
Current assignee: Kunming Yunda New Energy Co ltd
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2020-11-13

Abstract

The invention belongs to the technical field of electrochemical testing, and particularly relates to a double-sealing type multifunctional electrochemical testing device and an assembling and using method thereof. The device specifically comprises: the insulation corrosion-resistant die is provided with a cavity, and a first detachable electrolyte insulation sealing ring, a first electrode, a first air sealing ring and a first conductive tab are sequentially arranged on one side of the cavity of the insulation corrosion-resistant die; a detachable second electrolyte insulation sealing ring, a second electrode, a second air sealing ring and a second conductive tab are sequentially arranged on the other side of the insulation corrosion-resistant die cavity; a liquid injection hole is formed in the upper side of the insulating corrosion-resistant die cavity, and a third electrolyte insulating sealing ring and a sealing cover are sequentially arranged on the liquid injection hole; and a third penetrating electrode is fixedly arranged in the sealing cover. The sealing performance and the reliability of the whole system are guaranteed, and the multifunctional sealing device has the characteristics of simple structure, high operability, easiness in disassembly and cleaning, reusability and multiple functions.

Description

Double-sealing type multifunctional electrochemical testing device and assembling and using method thereof

Technical Field

The invention belongs to the technical field of electrochemical testing, and particularly relates to a double-sealing type multifunctional electrochemical testing device and an assembling and using method thereof.

Background

In the development process of new materials, the research on the physical and chemical properties of the materials plays a crucial role, wherein the research on the chemical properties has guiding significance on the preparation process, stability and application of the materials. More specifically, the electrochemical performance test of the material is an important essential means for the electrochemical research and application of the material.

In the process of testing the electrochemical performance of the material, a three-electrode system and a two-electrode system are the two most commonly used test systems. The three-electrode system includes a working electrode to generate an electrochemical reaction, a counter electrode to provide a current return, and a reference electrode to provide a stable electrode potential during the test. The working electrode is an electrode researched in an experimental process and usually comprises a glassy carbon electrode, a platinum electrode, a gold electrode or an electrode made of a researched material; the counter electrode is an electrode which forms a current loop with the working electrode without influencing the reaction of the whole system and is made of materials which must keep inertia in a research system, such as silver, nickel, tungsten, platinum and the like; the reference electrode is prepared from materials with known electrode potential, the electrode potential of the reference electrode in the whole reaction system is not affected, and common reference electrodes comprise a silver/silver chloride electrode, a calomel electrode, a silver/silver ion electrode, a lithium/lithium ion electrode and the like. In the test process, if the electrode potential of the counter electrode does not change or changes negligibly, the reference electrode can be omitted or the counter electrode can be used as the reference electrode at the same time, and the system is a two-electrode system. Through three-electrode or two-electrode testing, electrochemical performance data such as oxidation-reduction potential/current, working voltage, energy density, power density, mass transfer, adsorption, reversibility of electrochemical reaction and the like of an electrode material or electrolyte are obtained, and the characteristics of the electrode material and the electrolyte can be deeply and effectively researched from the theoretical aspect by comparing, analyzing and researching the data. According to the characteristics, the energy density, the working voltage, the rate capability, the high and low temperature performance, the corrosion resistance and the like can be improved in a targeted manner in the process of designing an electrochemical system and a device. Therefore, the electrochemical testing device with stable and reliable performance and convenient operation has extremely important significance for the research of the electrochemical performance of the material.

The utility model (CN 201320416874.6) discloses a three electrode system electrochemistry testing arrangement, including the main tank body that is used for annotating the outer cavity of liquid and interior cavity constitution in the structure, interior cavity is provided with the apron that is used for fixed working electrode, counter electrode and reference electrode, is provided with two circular ports and a bar hole on this apron, and the circular port is used for fixed auxiliary electrode and reference electrode, sets up lead screw adjusting device on the bar hole for fixed working electrode, this test system can realize simple operation and convenient test. However, the device only adopts a mode of opening holes on the cover plate to fix the working electrode, the reference electrode and the counter electrode, so that the airtightness is poor, and the device cannot be used for testing electrochemical reaction sensitive to air.

The invention (CN 201810415665.7) discloses a novel three-electrode system electrochemical testing device and a method, the device comprises a fixed base, a cylindrical device shell, an electrochemical device rear cover, a working electrode, an auxiliary electrode, a reference electrode and a pointer thermometer, the working electrode and the reference electrode are fixed in the device rear cover and sealed by silica gel, electrolyte is added through a cavity, and the working electrode is inserted into the cavity for liquid injection to realize sealing. Although the device realizes that the solution is only contacted with one surface of the working electrode and the reference electrode and is not contacted with the other surface (the counter electrode is soaked in the electrolyte), thereby avoiding the side reaction caused by soaking the wiring in the electrolyte, the problem that the other surface of the electrode which is easy to react with the air, such as lithium metal, and the like, can not be exposed in the air is not solved. Meanwhile, the whole system is sealed by using silica gel, the sealing performance may be met in a short time, but the air tightness is reduced due to long-time testing or under the condition of frequent movement, so that the obtained test data has great deviation. In addition, most of the conventional three-electrode testing devices insert three electrodes into the solution, the relative position deviation of each operation is different, and the testing results are different. On the other hand, although some three-electrode testing devices have a certain sealing property, the reliability and operability of the device are greatly affected by the numerous components and complicated assembly testing steps. Moreover, the electrode positions of the three-electrode testing devices are relatively fixed, so that the testing method and the application range of the device are greatly limited.

The main problems of the current electrochemical testing device include complex structure, poor air tightness, poor consistency of testing results, single function and the like. The defects cause that the accuracy, the repeatability and the operability of the test of the current electrochemical test device are greatly limited, so that the electrochemical test device which is simple in structure, good in air tightness, strong in operability, stable in performance and multifunctional and an assembling and using method thereof are urgently needed to be designed and manufactured aiming at the technical problems of complex structure, poor air tightness, poor test result consistency and single function.

Disclosure of Invention

The first purpose of the invention is to provide a double-sealing type multifunctional electrochemical testing device.

The second purpose of the invention is to provide an assembling method of the double-sealing multifunctional electrochemical testing device.

The first object of the present invention is achieved by: the device specifically comprises: the insulating corrosion-resistant die comprises an insulating corrosion-resistant die 1 provided with a cavity 12, wherein a detachable first electrolyte insulating sealing ring 801, a first electrode 2, a first air sealing ring 901 and a first conductive tab 3 are sequentially arranged on one side of the cavity 12 of the insulating corrosion-resistant die 1; the other side of the cavity 12 of the insulating corrosion-resistant die 1 is sequentially provided with a detachable second electrolyte insulating sealing ring 802, a second electrode 4, a second air sealing ring 902 and a second conductive tab 5; a liquid injection hole 11 is formed in the upper side of the cavity 12 of the insulating corrosion-resistant die 1, and a third electrolyte insulating sealing ring 803 and a sealing cover 7 are sequentially arranged on the liquid injection hole 11; a third electrode 6 is fixedly arranged in the sealing cover 7.

The second object of the present invention is achieved by: the assembling method specifically comprises the following steps:

the method comprises the following steps: the first electrolyte insulating sealing ring 801, the first electrode 2, the first air sealing ring 901 and the first conductive tab 3 are sequentially placed on an insulating corrosion-resistant mold 1 with a cavity 12, and are fixed and compressed through a bolt 10;

step two: the second electrolyte insulating sealing ring 802, the second electrode 4, the second air sealing ring 902 and the second conductive tab 5 are sequentially placed on an insulating corrosion-resistant mold 1 provided with a cavity 12 and are fixed and compressed through a bolt 10;

step three: electrolyte is injected into the cavity 12 through the injection hole 11, so that the electrolyte submerges the first electrode 2 and the second electrode 4;

step four: the third electrolyte insulation sealing ring 803 is placed in the liquid injection hole 11, and the sealing cover 7 tightly connected with the third electrode 6 is screwed, so that the whole system is sealed, and the electrode surface of the third electrode 6 is positioned at the right center of the cavity 12 and is on the same horizontal line with the centers of the first electrode 2 and the second electrode 4;

step five: and connecting an instrument or equipment with the first conductive tab 3, the second conductive tab 5 and the third electrode 6 respectively, and testing at required temperature in real time.

According to the double-sealing multifunctional electrochemical testing device and the assembling and using method thereof, the mould 1 with the cavity 12, the first electrode 2, the second electrode 4, the third electrode 6, the electrolyte insulating sealing ring 8 and the air sealing ring 9 which can be flexibly disassembled can be used for compressing and fixing, all parts are mutually independent and can be freely disassembled and adjusted, the sealing property and the reliability of the whole system are ensured, and the double-sealing multifunctional electrochemical testing device also has the characteristics of simple structure, high operability, easiness in disassembling and cleaning and reusability.

The centers of the first electrode 2 and the second electrode 4 are on the same horizontal line, and the electrode surface of the third electrode 6 is positioned at the positive center of the horizontal line, so that the spatial positions of the first electrode 2 and the second electrode 4 can be fully ensured to be at fixed positions during each test, and the consistency and the reliability of the test can be fully ensured.

The die 1 is made of materials which are electrically insulated, electrochemically inert and have excellent mechanical strength, does not generate side reaction with electrolyte, and has stable performance, thereby ensuring the accuracy of test results.

The electrolyte is only contacted with the reaction surfaces of the first electrode 2, the second electrode 4 and the third electrode 6, but not contacted with a current collector connected with an external circuit, so that the accuracy of the test result is ensured.

The first conductive tab 3 and the second conductive tab 5 are not in contact with the electrolyte, so that the conductive tabs are prevented from reacting in a test, the accuracy of a test result is ensured, and the service life of the whole system is effectively prolonged.

The device has double sealing performance, can ensure that the first electrode 2 and the second electrode 4 do not contact with the electrolyte and do not contact with air, can effectively prevent air from entering the electrolyte, and ensures the accuracy of a test result.

Electrolyte is filled through the electrolyte filling hole 11, and the amount of the added electrolyte can be adjusted by adjusting the size of the cavity, so that the required performance can be accurately measured under the condition of extremely small amount of electrolyte.

The test device can be used for testing a three-electrode system and a two-electrode system, and has wide use functions.

The first electrode 2, the second electrode 4 and the third electrode 6 can be flexibly changed to meet the requirements of different test purposes.

The electrochemical test system can be used for testing electrolyte and electrode materials, and is an omnibearing electrochemical research system.

In a word, the electrochemical testing device and the assembling and using method thereof have the characteristics of simple structure, good air tightness, strong operability, stable performance and multiple functions.

Drawings

FIG. 1 is a side sectional view of a dual sealed multi-functional electrochemical testing device in accordance with the present invention;

FIG. 2 is a perspective view of the components and assembly of a dual-seal multifunctional electrochemical testing apparatus according to the present invention;

FIG. 3 is a cyclic voltammogram of a three-electrode system of the device of the present invention used to test a conventional electrolyte;

FIG. 4 is a cyclic voltammogram of a three-electrode system of the apparatus of the present invention after the addition of a negative additive to a conventional electrolyte;

FIG. 5 is a cyclic voltammogram of a three-electrode system of the device of the present invention used to test a conventional electrolyte;

FIG. 6 is a cyclic voltammogram of a three-electrode system of the inventive device after the addition of a positive additive to a conventional electrolyte;

FIG. 7 is a cyclic voltammetry curve for testing a lithium ion battery positive electrode material using a three-electrode system of the device of the present invention;

FIG. 8 is a cyclic voltammetry curve for testing lithium ion battery negative electrode materials using a three-electrode system of the device of the present invention;

FIG. 9 is a cyclic voltammetry curve for testing a lithium ion battery positive electrode material using a two-electrode system of the device of the present invention;

FIG. 10 is a cyclic voltammogram of a two-electrode system of the device of the present invention used to test a lithium ion battery negative electrode material;

FIG. 11 is a schematic flow chart illustrating a method for assembling and using a dual-sealed multifunctional electrochemical testing device according to the present invention;

in the figure:

1-a mould; 2-a first electrode; 3-a first conductive tab; 4-a second electrode; 5-a second conductive tab; 6-a third electrode; 7-sealing cover; 8-electrolyte insulation sealing ring; 801-first electrolyte insulation sealing ring; 802-second electrolyte insulating seal ring; 803-third electrolyte insulating seal ring; 9-air sealing ring; 901-a first air sealing ring; 902-a second air sealing ring; 10-bolt; 11-liquid injection hole; 12-a cavity.

Detailed Description

The invention is further illustrated in the following figures and examples in order to provide the person skilled in the art with a detailed understanding of the invention, without restricting it in any way. Any variations or modifications made in accordance with the teachings of the present invention are intended to be within the scope of the present invention.

The invention is further elucidated with reference to the drawing.

As shown in fig. 1-2, the present invention provides a dual-sealed multifunctional electrochemical testing device, which specifically comprises: the insulating corrosion-resistant die comprises an insulating corrosion-resistant die 1 provided with a cavity 12, wherein a detachable first electrolyte insulating sealing ring 801, a first electrode 2, a first air sealing ring 901 and a first conductive tab 3 are sequentially arranged on one side of the cavity 12 of the insulating corrosion-resistant die 1; the other side of the cavity 12 of the insulating corrosion-resistant die 1 is sequentially provided with a detachable second electrolyte insulating sealing ring 802, a second electrode 4, a second air sealing ring 902 and a second conductive tab 5; a liquid injection hole 11 is formed in the upper side of the cavity 12 of the insulating corrosion-resistant die 1, and a third electrolyte insulating sealing ring 803 and a sealing cover 7 are sequentially arranged on the liquid injection hole 11; a third electrode 6 is fixedly arranged in the sealing cover 7.

The detachable connection is specifically a fixed compression connection through a bolt 10.

The third electrode 6 and the sealing cover 7 are coaxially arranged.

The first electrode 2 is specifically a counter electrode, or a working electrode, or a reference electrode; the second electrode 4 is specifically a reference electrode, or a counter electrode, or a working electrode; the third electrode 6 is specifically a working electrode, or a reference electrode, or a counter electrode.

The preparation material of the sealing cover 7 has electric insulation, excellent mechanical property and no electrochemical activity.

The preparation material of the insulating and corrosion-resistant mold 1 with the cavity 12 has electric insulation, excellent mechanical property and no electrochemical activity.

The first conductive tab 3 is made of a high-strength high-conductivity metal; the second conductive tab 5 is made of a high-strength high-conductivity metal.

The preparation material of the first electrode 2 has electrochemical inertia and high conductivity; the third electrode 6 is made of a material that is electrochemically inert and highly conductive.

The lower end surface of the third electrode 6, the center point of the cavity 12, the center point of the first electrode 2 and the center point of the second electrode 4 are on the same horizontal line.

The invention also provides an assembly method of the double-sealing multifunctional electrochemical testing device, which comprises the following steps:

Specifically, in the embodiment of the present invention, the first electrode 2 is a counter electrode, the second electrode 4 is a reference electrode, the third electrode 4 is a working electrode, the first conductive tab 3 is a conductive tab in close contact with the counter electrode, that is, a counter electrode conductive tab, and the second conductive tab 5 is a conductive tab in close contact with the reference electrode, that is, a reference electrode conductive tab.

That is, a double-sealed type multifunctional electrochemical test device, comprising: the testing device comprises an insulating corrosion-resistant die 1 provided with a cavity 12, a counter electrode and a conductive tab closely contacted with the counter electrode, wherein the reference electrode, the conductive tab closely contacted with the reference electrode and an electrolyte insulating sealing ring 8 realize a semi-sealed cavity, the counter electrode and the reference electrode are isolated from the outside air through an air sealing ring 9, the conductive tab of the counter electrode and the conductive tab of the reference electrode are fixed by a bolt 10, a certain amount of electrolyte is added into the semi-sealed cavity 12 through a liquid injection hole 11, finally, a sealing cover 7 connected with a working electrode is screwed to closely contact with the electrolyte insulating sealing ring 8 to realize the full-sealed state of the whole system, and the testing is respectively carried out on the conductive tab of the counter electrode, the conductive tab of the reference electrode and the wiring.

The insulating corrosion-resistant die 1 provided with the cavity 12 and the sealing cover 7 tightly connected with the working electrode are made of electrically insulating and electrochemically-inactive materials with excellent mechanical properties; the counter electrode conductive tab and the reference electrode conductive tab are made of high-strength and high-conductivity metal.

The counter electrode is made of a material with electrochemical inertia and high conductivity, only one side of the counter electrode is contacted with the electrolyte through an electrolyte insulation sealing ring 8, and the other side of the counter electrode is tightly connected with a conductive tab of the counter electrode.

The extrusion of the counter electrode conductive tab on the air sealing ring 9 is utilized to realize the isolation of the counter electrode and the external air, and the extrusion of the counter electrode conductive tab on the counter electrode and the electrolyte insulation sealing ring 8 is utilized to avoid the electrolyte from permeating to the other side of the counter electrode conductive tab.

The reference electrode is composed of an electric pair with stable electrode potential in a test system, only one side of the reference electrode is contacted with the electrolyte by closely contacting the electrolyte insulating seal ring 8, and the other side of the reference electrode is closely connected with a conductive tab of the reference electrode.

The reference electrode is isolated from the outside air by extruding the air seal ring 9 by the reference electrode conductive lug, and the electrolyte is prevented from permeating to the other side of the reference electrode conductive lug by extruding the reference electrode conductive lug to the reference electrode and the electrolyte insulation seal ring 8.

The working electrode for the electrochemical reaction to take place is made of a material which is electrochemically inert and highly conductive, or is made of a material under investigation, fixed to a sealing cap 7 with a thread.

Electrolyte is added into the electrolyte cavity 12 through the electrolyte injection hole 11 at the top end, so that the electrolyte can submerge the counter electrode and the reference electrode.

The working electrode is tightly connected with the sealing cover 7, and the whole system is sealed by extruding the electrolyte insulation sealing ring 8 after screwing. The electrode surface of the working electrode is located just in the center of the electrolyte cavity 12 and is level with the center of the counter and reference electrodes.

The device can be used for testing a three-electrode system and can also be used for testing a two-electrode system. In order to meet different test purposes, the counter electrode, the reference electrode and the working electrode can be replaced according to the requirements. The device can be used for the research of electrolyte and electrode materials.

In other words, in the embodiment of the present invention, the apparatus includes a mold 1 having an electrolyte cavity, a counter electrode, a reference electrode, and a working electrode in sequence, the counter electrode and the reference electrode are respectively arranged at two sides of the electrolyte cavity 12 and are tightly contacted with the electrolyte insulating sealing ring 8, the counter electrode conductive tab is simultaneously in close contact with the counter electrode and the air seal ring 9, the reference electrode conductive tab is simultaneously in close contact with the reference electrode and the air seal ring 9, the fastening bolt 10 is used for connecting a counter electrode conductive tab and a reference electrode conductive tab, the working electrode is tightly connected with the threaded sealing cover 7, the liquid injection hole 11 is internally provided with a thread, the sealing cover 7 is tightly contacted with the electrolyte insulating sealing ring 8, the electrolyte cavity 12 is positioned right below the liquid injection hole 11, and the centers of the counter electrode and the reference electrode, the electrode surface of the working electrode and the center of the electrolyte cavity 12 are positioned at the same position.

The mould 1 provided with the cavity and the sealing cover 7 are made of electrically insulating, electrochemically inert and mechanically strong materials, such as: polyetheretherketone (PEEK), Polytetrafluoroethylene (PTFE), High Density Polyethylene (HDPE), or organic glass (PMMA), etc., and the material can be adjusted according to the chemical properties of the electrolyte used in the test.

The counter electrode is made of a material with electrochemical inertness and high conductivity, such as: noble metals (such as platinum, gold, etc.) or carbon materials, etc., and suitable materials can be selected according to the use requirements.

The reference electrode is composed of an electrical pair having a stable electrode potential in the test system, such as: a silver/silver chloride electrode, a calomel electrode, a silver/silver ion electrode, a lithium/lithium ion electrode, a metal/metal oxide electrode and the like, and a proper reference electrode can be selected according to the use requirement.

The counter electrode conductive lug and the reference electrode conductive lug are made of high-strength and high-conductivity metals, such as: copper, gold-plated copper, stainless steel, aluminum, or aluminum alloy, etc.

The working electrode is made of a material having electrochemical inertness and high conductivity, such as: noble metals (such as platinum, gold and the like), carbon materials and the like, or prepared from researched materials, and an appropriate electrode material can be selected according to the use requirement.

The electrolyte insulating seal ring 8 and the air seal ring 9 are made of chemically inert flexible materials, such as: polyether ether ketone (PEEK), Polytetrafluoroethylene (PTFE), rubber, or High Density Polyethylene (HDPE), and the like. The fastening bolt 10 is made of high-strength stainless steel, aluminum alloy, or PEEK, or the like.

A method for assembling and using a double-sealing type multifunctional electrochemical testing device specifically comprises the following steps:

step one (S1): and sequentially placing the electrolyte insulating sealing ring 8, the counter electrode, the air sealing ring 9 and the counter electrode conductive lug on the insulating corrosion-resistant mold 1 provided with the electrolyte cavity 12, and fixing and pressing the insulating corrosion-resistant mold through the bolt 10.

Step two (S2): and sequentially placing the electrolyte insulating seal ring 8, the reference electrode, the air seal ring 9 and the reference electrode conductive lug on the insulating corrosion-resistant mold 1 provided with the electrolyte cavity 12, and fixing and pressing the electrolyte insulating seal ring, the reference electrode, the air seal ring 9 and the reference electrode conductive lug through bolts 10.

Step three (S3): a certain amount of electrolyte is injected into the cavity 12 through the injection hole 11, so that the electrolyte submerges the counter electrode and the reference electrode.

Step four (S4): the electrolyte insulation sealing ring 8 is placed in the liquid injection hole 11, the sealing cover 7 tightly connected with the working electrode is screwed to ensure the whole system to be sealed, and meanwhile, the electrode surface of the working electrode is just positioned at the center of the cavity 12 and is positioned on the same horizontal line with the centers of the counter electrode and the reference electrode.

Step five (S5): and respectively connecting an instrument or equipment with the counter electrode conductive tab, the reference electrode conductive tab and the working electrode, and testing at the required temperature.

Example 1:

the cyclic voltammetry curve of the conventional electrolyte is tested by adopting a three-electrode system by using the device of the invention:

1. placing an electrolyte insulating seal ring 8 into a die 1 provided with a cavity, and then closely contacting a platinum sheet counter electrode 2 with the electrolyte insulating seal ring 8;

2. placing an air seal ring 9 into the seal groove, and placing a counter electrode conductive tab 3 into close contact with the platinum sheet counter electrode 2 and the air seal ring 9;

3. fixing a counter electrode conductive tab 3 on a die 1 provided with a cavity by using a fastening bolt 10, and simultaneously pressing an air seal ring 9 and a platinum sheet counter electrode 2;

4. placing an electrolyte insulating seal ring 8 to the other side of the die 1 with the cavity, and then tightly contacting the lithium sheet reference electrode 4 with the electrolyte insulating seal ring 8;

5. placing an air seal ring 9 into the seal groove, and placing a reference electrode conductive tab 5 into close contact with the lithium sheet reference electrode 4 and the air seal ring 9;

6. fixing a reference electrode conductive tab 5 on a die 1 provided with a cavity by using a fastening bolt 10, and simultaneously pressing an air seal ring 9 and a lithium sheet reference electrode 4;

7. adding 0.8 mL of a conventional electrolyte (1M LiPF6-EC/DMC/EMC (1: 1: 1)) into the electrolyte cavity 12 through the electrolyte injection hole 11;

8. sleeving an electrolyte insulating seal ring 8 on a glassy carbon working electrode 6, screwing a seal cover 7 tightly connected with the glassy carbon working electrode 6 into a threaded liquid injection hole 11, so that the electrode surface of the glassy carbon electrode 6 is sealed and adjusted to be positioned at the center of an electrolyte cavity 12 and to be positioned on the same horizontal line with the centers of a counter electrode 2 and a reference electrode 4;

9. respectively connecting a meter and equipment with a counter electrode conductive tab 3, a reference electrode conductive tab 5 and a glassy carbon working electrode 6, and then carrying out cyclic voltammetry on the electrolyte at a scanning speed of 0.5 mV/s within a voltage range of 0-3.5V at room temperature;

10. and (3) testing results: FIG. 3 is a cyclic voltammogram of a conventional electrolyte;

11. and (4) analyzing results: the conventional electrolyte showed a reduction peak at 0.49V in the first turn, and the reduction peak disappeared in the second and third turns, indicating that the reduction product of the electrolyte on the working electrode had formed a protective film.

Example 2:

the device of the invention adopts a three-electrode system to test the cyclic voltammetry curve of the conventional electrolyte after adding the cathode additive:

7. adding 0.8 mL of conventional electrolyte added with a negative electrode additive into the electrolyte cavity 12 through the electrolyte injection hole 11;

10. and (3) testing results: FIG. 4 is a cyclic voltammogram of a conventional electrolyte containing a negative electrode additive;

11. and (4) analyzing results: at the first turn, the conventional electrolyte containing the negative electrode additive showed a new reduction peak at a more positive voltage (1.95V) in addition to the 0.57V reduction peak of the conventional electrolyte, at the second turn, the two reduction peaks were reduced, and at the third turn, both reduction peaks completely disappeared, indicating that the reduction product of the electrolyte on the working electrode had formed a protective film. In particular, since the anode additive is more easily reduced, a more stable protective film is more easily formed on the working electrode.

Example 3:

7. adding 0.8 mL of conventional electrolyte into the electrolyte cavity 12 through the electrolyte injection hole 11;

9. the method comprises the steps of respectively connecting a meter and equipment with a counter electrode conductive tab 3, a reference electrode conductive tab 5 and a glassy carbon working electrode 6, and then carrying out cyclic voltammetry test on an electrolyte at a scanning speed of 5 mV/s within a voltage range of 3-7V at room temperature.

10. And (3) testing results: FIG. 5 is a cyclic voltammogram of a conventional electrolyte;

11. and (4) analyzing results: as can be seen from the cyclic voltammogram of fig. 5, the stable electrochemical window of the electrolyte gradually narrowed with increasing number of cycles (first cycle: 6.50V, second cycle: 6.45V, third cycle: 6.40V), indicating the continued decomposition of the conventional electrolyte and its instability.

Example 4:

the cyclic voltammetry curve of the conventional electrolyte containing the positive electrode additive is tested by adopting a three-electrode system by using the device disclosed by the invention:

7. adding 0.8 mL of conventional electrolyte containing a positive electrode additive into the electrolyte cavity 12 through the electrolyte injection hole 11;

10. And (3) testing results: FIG. 6 is a cyclic voltammogram of a conventional electrolyte containing a positive electrode additive;

11. and (4) analyzing results: as can be seen from the cyclic voltammogram of fig. 6, the conventional electrolyte containing the positive electrode additive undergoes preferential oxidation of the additive at 4.25V, and the oxidation current thereof gradually decreases with the increase in the number of cycles, indicating that the oxidation product of the additive on the working electrode gradually forms a protective film. Meanwhile, as the number of cycles increases, the stable electrochemical window of the electrolyte gradually widens (first circle: 6.15V, second circle: 6.40V, third circle: 6.60V), indicating that the protective film formed by the oxidation product of the positive electrode additive on the working electrode can simulate further decomposition of the electrolyte and improve the stability thereof.

Example 5:

the device of the invention adopts a three-electrode system to test the cyclic voltammetry curve of the lithium ion battery anode material:

8. sleeving an electrolyte insulating seal ring 8 on a platinum working electrode 6 coated with a lithium ion battery anode material, screwing a seal cover 7 tightly connected with the working electrode 6 into a threaded liquid injection hole 11, so that the seal cover seals and adjusts the electrode surface of the working electrode 6 to be positioned at the center of an electrolyte cavity 12 and to be positioned on the same horizontal line with the centers of a counter electrode 2 and a reference electrode 4;

9. respectively connecting a meter and equipment with a counter electrode conductive tab 3, a reference electrode conductive tab 5 and a working electrode 6, and then performing cyclic voltammetry test at a scanning speed of 0.05 mV/s in a voltage range of 2-4.2V at room temperature;

10. and (3) testing results: FIG. 7 is a cyclic voltammogram of a lithium ion battery positive electrode material;

11. and (4) analyzing results: as can be seen from the cyclic voltammogram of fig. 7, the positive electrode material shows a distinct oxidation peak at 3.60V in the positive direction scan, and a distinct reduction peak at 3.27V in the negative direction scan, indicating typical processes of delithiation (oxidation) and lithium insertion (reduction) of the positive electrode material.

Example 6:

the device of the invention adopts a three-electrode system to test the cyclic voltammetry curve of the lithium ion battery cathode material:

8. sleeving an electrolyte insulating seal ring 8 on a platinum working electrode 6 coated with a lithium ion battery cathode material, screwing a seal cover 7 tightly connected with the working electrode 6 into a threaded liquid injection hole 11, so that the seal cover seals and adjusts the electrode surface of the working electrode 6 to be positioned at the center of an electrolyte cavity 12 and to be positioned on the same horizontal line with the centers of a counter electrode 2 and a reference electrode 4;

9. respectively connecting a meter and equipment with a counter electrode conductive tab 3, a reference electrode conductive tab 5 and a working electrode 6, and then performing cyclic voltammetry test at a scanning speed of 0.05 mV/s within a voltage range of 3-0.005V at room temperature;

10. and (3) testing results: FIG. 8 is a cyclic voltammogram of a lithium ion battery negative electrode material;

11. and (4) analyzing results: as can be seen from the cyclic voltammogram of fig. 8, the negative electrode material showed a distinct reduction peak (corresponding to the formation of the solid electrolyte membrane on the negative electrode) at 0.38V, at 0.11V and 0.005V, and at 0.20V and 0.26V, during the negative scan, indicating typical lithium intercalation (reduction) and de-lithiation (oxidation) processes of the negative electrode material.

Example 7:

the device of the invention adopts a two-electrode system to test the cyclic voltammetry curve of the lithium ion battery anode material:

1. placing an electrolyte insulating seal ring 8 into a die 1 provided with a cavity, and then replacing a platinum sheet counter electrode 2 (namely, a positive plate 2) with an aluminum foil coated with a lithium ion battery positive electrode material to be in close contact with the electrolyte insulating seal ring 8;

2. placing an air seal ring 9 into the seal groove, and placing the counter electrode conductive tab 3 into close contact with the positive plate 2 and the air seal ring 9;

3. fixing a counter electrode conductive tab 3 on a die 1 provided with a cavity by using a fastening bolt 10, and simultaneously pressing an air sealing ring 9 and a positive plate 2;

4. placing an electrolyte insulating seal ring 8 to the other side of the die 1 with a cavity, and then tightly contacting the lithium sheet counter electrode/reference electrode 4 with the electrolyte insulating seal ring 8;

5. placing an air seal ring 9 into the seal groove, and placing a reference electrode conductive tab 5 into close contact with the lithium sheet counter electrode/reference electrode 4 and the air seal ring 9;

6. fixing a reference electrode conductive tab 5 on a die 1 provided with a cavity by using a fastening bolt 10, and simultaneously pressing an air seal ring 9 and a lithium sheet counter electrode/reference electrode 4;

8. sleeving an electrolyte insulating seal ring 8 on a working electrode 6, screwing a seal cover 7 tightly connected with the working electrode 6 into a threaded liquid injection hole 11, so that the seal cover seals and adjusts the electrode surface of the working electrode 6 to be positioned at the central position of an electrolyte cavity 12 and to be positioned on the same horizontal line with the centers of a positive plate 2 and a lithium plate counter electrode/reference electrode 4;

9. respectively connecting a meter and equipment with a counter electrode conductive tab 3 and a reference electrode conductive tab 5 (note: the counter electrode conductive tab 3 of an electrochemical testing device is connected with a working electrode of testing equipment, the reference electrode conductive tab 5 of the electrochemical testing device is connected with the counter electrode and the reference electrode of the testing equipment, and the working electrode 6 of the electrochemical testing device is not connected with the testing equipment), and then carrying out cyclic voltammetry testing at a scanning speed of 0.05 mV/s within a voltage range of 2-4.2V at room temperature;

10. and (3) testing results: FIG. 9 is a cyclic voltammogram of a lithium ion battery positive electrode material;

11. and (4) analyzing results: as can be seen from the cyclic voltammogram of fig. 9, the positive electrode material shows a distinct oxidation peak at 4.04V in the forward direction scan, and a distinct reduction peak at 3.03V in the reverse direction scan, indicating typical processes of delithiation (oxidation) and lithium insertion (reduction) of the positive electrode material.

Example 8:

the device of the invention adopts a two-electrode system to test the cyclic voltammetry curve of the lithium ion battery cathode material:

1. placing an electrolyte insulating seal ring 8 into a die 1 provided with a cavity, and then replacing a platinum sheet counter electrode 2 (namely, a negative electrode sheet 2) with copper foil coated with a lithium ion battery negative electrode material to be in close contact with the electrolyte insulating seal ring 8;

2. placing an air seal ring 9 into the seal groove, and placing the counter electrode conductive tab 3 into close contact with the negative plate 2 and the air seal ring 9;

3. fixing a counter electrode conductive tab 3 on a die 1 provided with a cavity by using a fastening bolt 10, and simultaneously pressing an air sealing ring 9 and a negative plate 2;

8. sleeving an electrolyte insulating seal ring 8 on a working electrode 6, screwing a seal cover 7 tightly connected with the working electrode 6 into a threaded liquid injection hole 11, so that the seal cover seals and adjusts the electrode surface of the working electrode 6 to be positioned at the central position of an electrolyte cavity 12 and to be positioned on the same horizontal line with the centers of a negative plate 2 and a lithium plate counter electrode/reference electrode 4;

9. respectively connecting a meter and equipment with a counter electrode conductive tab 3 and a reference electrode conductive tab 5 (note: the counter electrode conductive tab 3 of an electrochemical testing device is connected with a working electrode of testing equipment, the reference electrode conductive tab 5 of the electrochemical testing device is connected with the counter electrode and the reference electrode of the testing equipment, and the working electrode 6 of the electrochemical testing device is not connected with the testing equipment), and then carrying out cyclic voltammetry testing at a scanning speed of 0.05 mV/s within a voltage range of 3-0.005V at room temperature;

10. and (3) testing results: FIG. 10 is a cyclic voltammogram of a lithium ion battery negative electrode material;

11. and (4) analyzing results: as can be seen from the cyclic voltammetry curve of fig. 10, the negative electrode material shows a distinct reduction peak (corresponding to the formation of the solid electrolyte membrane on the negative electrode) at 0.76V before 0.76V in the negative scan, a distinct reduction peak at 0.005V and a distinct oxidation peak at 0.60V in the positive scan, indicating typical lithium intercalation (reduction) and lithium deintercalation (oxidation) processes of the negative electrode material.

Aiming at the defects and shortcomings of the existing electrochemical testing device, the invention provides the multifunctional electrochemical testing device with simple structure, good air tightness, strong operability, stable performance and multiple functions. The device can be used for testing a three-electrode system or a two-electrode system according to the requirements of different testing purposes; the positions of the counter electrode, the reference electrode and the working electrode can be randomly switched; can be used for the research of electrolyte or electrode materials.

The invention is realized by the following steps: including mould, counter electrode, reference electrode, the insulating sealing washer of electrolyte, air seal ring and the conductive utmost point ear of counter electrode, reference electrode that are equipped with the cavity, the cavity of mould and the geometric center of counter electrode and reference electrode are on same water flat line, the bolt is fixed both sides utmost point ear on the mould, compresses tightly air seal ring and the insulating sealing washer of electrolyte simultaneously, the electrode surface of working electrode is at the geometric center of cavity, annotate the liquid hole and be in directly over the mould cavity and the size slightly is greater than the working electrode, sealed lid closely links to each other with the working electrode, it is unanimous with the working electrode to annotate downthehole electrolyte insulating sealing washer internal diameter of liquid.

Compared with the prior art, the device of the invention has the following beneficial effects:

1. through the mould that is equipped with the cavity that can nimble split, counter electrode, reference electrode, working electrode and electrolyte insulation sealing circle and air seal compress tightly and fix, and each part is independent can freely be dismantled and adjust each other, when guaranteeing the leakproofness and the reliability of whole system, still has simple structure, maneuverability height, easily dismantles washing and repeatedly usable's characteristics.

2. The centers of the counter electrode and the reference electrode are on the same horizontal line, and the electrode surface of the working electrode is positioned at the right center of the horizontal line, so that the spatial positions of the counter electrode and the reference electrode are fully ensured to be at fixed positions in each test, and the consistency and the reliability of the test can be fully ensured.

3. The die is made of materials which are electrically insulated and electrochemically inert and have excellent mechanical strength, does not generate side reaction with electrolyte, and has stable performance, so that the accuracy of a test result is ensured.

4. The electrolyte only contacts with the working electrode, the reference electrode and the reaction surface of the counter electrode, but not with the current collector connected with an external circuit, thereby ensuring the accuracy of the test result.

5. The counter electrode conductive tab and the reference electrode conductive tab are not in contact with the electrolyte, so that the conductive tabs are prevented from reacting in the test, the accuracy of the test result is ensured, and the service life of the whole system is effectively prolonged.

6. The invention has double sealing performance, can ensure that the sides of the counter electrode and the reference electrode which are not in contact with the electrolyte are not in contact with air, thereby selecting some materials which are more active in the air as electrode materials, such as lithium, sodium, potassium and the like, and also more effectively preventing the air from entering the electrolyte, and ensuring the accuracy of a test result.

7. The electrolyte is filled through the liquid filling port, and the amount of the added electrolyte can be adjusted by adjusting the size of the cavity, so that the required performance can be accurately measured under the condition of extremely small amount of electrolyte.

8. The invention can be used for testing a three-electrode system and a two-electrode system, and has wide use functions.

9. The counter electrode, the reference electrode and the working electrode can be flexibly changed to meet the requirements of different test purposes.

10. The invention can be used for testing electrolyte and electrode materials, and is an omnibearing electrochemical research system.

In a word, the electrochemical testing device has the characteristics of simple structure, good air tightness, strong operability, stable performance and multiple functions.

Claims

1. A double-sealed multifunctional electrochemical testing device is characterized by specifically comprising: the insulation corrosion-resistant die comprises an insulation corrosion-resistant die (1) provided with a cavity (12), wherein a detachable first electrolyte insulation sealing ring (801), a first electrode (2), a first air sealing ring (901) and a first conductive tab (3) are sequentially arranged on one side of the cavity (12) of the insulation corrosion-resistant die (1); the other side of the cavity (12) of the insulating corrosion-resistant die (1) is sequentially provided with a detachable second electrolyte insulating sealing ring (802), a second electrode (4), a second air sealing ring (902) and a second conductive tab (5); a liquid injection hole (11) is formed in the upper side of a cavity (12) of the insulating corrosion-resistant die (1), and a third electrolyte insulating sealing ring (803) and a sealing cover (7) are sequentially arranged on the liquid injection hole (11); and a third penetrating electrode (6) is fixedly arranged in the sealing cover (7).

2. A double-sealed multifunctional electrochemical testing device according to claim 1, characterized in that said detachable connection is embodied as a fixed compression connection by means of a bolt (10).

3. A double sealed multifunctional electrochemical test device according to claim 1, characterized in that said third electrode (6) and said sealing cover (7) are coaxially arranged.

4. The double-sealed multifunctional electrochemical test device according to claim 1, wherein the first electrode (2) is a counter electrode, a working electrode, or a reference electrode; the second electrode (4) is a reference electrode, a counter electrode or a working electrode; the third electrode (6) is a working electrode, a reference electrode or a counter electrode.

5. A double sealed multifunctional electrochemical test device according to claim 1 or 3, characterized in that the sealing cover (7) is made of a material having electrical insulation, mechanical properties and no electrochemical activity.

6. The double-sealed multifunctional electrochemical testing device according to claim 1, wherein the insulating and corrosion-resistant mold (1) with the cavity (12) is made of a material having electrical insulation, mechanical properties and no electrochemical activity.

7. The double-sealed multifunctional electrochemical testing device according to claim 1, characterized in that the first conductive tab (3) is made of a material, in particular a high-strength high-conductivity metal; the second conductive tab (5) is made of a high-strength high-conductivity metal.

8. The double-sealed multifunctional electrochemical test device according to claim 1 or 4, wherein the first electrode (2) is made of a material that is electrochemically inert and highly electrically conductive; the third electrode (6) is made of a material which is electrochemically inert and highly conductive.

9. The double-sealed multifunctional electrochemical test device according to claim 1, wherein the lower end surface of the third electrode (6) and the center point of the cavity (12), the center point of the first electrode (2), and the center point of the second electrode (4) are on the same horizontal line.

10. The method for assembling a double-sealed multifunctional electrochemical test device according to any one of claims 1 to 9, wherein the method for assembling comprises the following steps:

the method comprises the following steps: the first electrolyte insulating sealing ring (801), the first electrode (2), the first air sealing ring (901) and the first conductive tab (3) are sequentially placed on an insulating corrosion-resistant mold (1) with a cavity (12), and are fixed and compressed through a bolt (10);

step two: the second electrolyte insulating sealing ring (802), the second electrode (4), the second air sealing ring (902) and the second conductive tab (5) are sequentially placed on an insulating corrosion-resistant mold (1) with a cavity (12), and are fixed and compressed through a bolt (10);

step three: electrolyte is injected into the cavity (12) through the injection hole (11) so that the electrolyte submerges the first electrode (2) and the second electrode (4);

step four: placing the third electrolyte insulating sealing ring (803) in the liquid injection hole (11), and screwing a sealing cover (7) tightly connected with the third electrode (6) so that the whole system is sealed, and the electrode surface of the third electrode (6) is positioned at the right center of the cavity (12) and is positioned on the same horizontal line with the centers of the first electrode (2) and the second electrode (4);

step five: and (3) connecting an instrument or equipment with the first conductive tab (3), the second conductive tab (5) and the third electrode (6) respectively, and testing at required temperature in real time.