KR20060068117A - Reference electrode probe for 3 electrode system and method for measurement of electrode potential of secondary battery using the same - Google Patents

Abstract

The reference electrode probe for measuring the electrode potential of the three-electrode system of the present invention is inserted into the through hole of the battery case, the electrically insulating member that can be installed while maintaining the seal, and the upper surface vertically penetrating the center of the insulating member and It consists of including the conductive needle-like member which protrudes in the lower end surface.

Electrode potential probe of the present invention is easy to manufacture due to the simple structure, can quickly and accurately measure the electrode potential of the actual operating state of the secondary battery, it is also possible to measure under various experimental conditions.

Description

Reference electrode probe for measuring electrode potential and measuring electrode potential of secondary battery using same {Reference Electrode Probe for 3 Electrode System And Method for Measurement of Electrode Potential of Secondary Battery Using The Same}             

1 is a schematic front view of a reference electrode probe according to an embodiment of the present invention;

FIG. 2 is an exemplary configuration diagram of measuring electrode potential of a rectangular secondary battery using the reference electrode probe of FIG. 1.

<Description of Major Symbols in Drawing>

100: reference electrode probe

200: electrically insulating member

300: needle member

400: secondary battery

500: device for measuring electrode potential

The present invention relates to a reference electrode probe for measuring the three-electrode electrode potential and a method for measuring the electrode potential of a secondary battery using the same.

In general, the electrode potential of the battery is measured for the development of a new battery, the performance of the manufactured battery, and the like. For measuring the electrode potential, a three-electrode-based electrode potential measuring method including a reference electrode, a working electrode, and a potential electrode is mainly used.

The reference electrode is an electrode used to make a battery circuit for measuring electrode potential in combination with the electrode for measuring the potential of an electrode constituting a battery or an electrode in which electrolysis is occurring. It becomes the standard of.

Such a reference electrode should follow the Nernst equilibrium equation as a reversible electrode potential (electrode in reversible state), have a non-polarization characteristic that always maintains a constant potential value, have a small potential difference between liquids, and change potentials even when temperature changes The change shall be small and the requirements such as showing a constant potential value at a constant temperature shall be met.

In this regard, in the field of secondary batteries, which are growing rapidly in recent years, the measurement of electrode potential has been performed for the development of new batteries and the improvement of performance of existing batteries. Generally, the conventional method is used as it is for the electrode potential measurement of such a secondary battery. For example, when measuring the performance of the newly developed positive electrode active material, the electrode potential is measured by placing an electrolyte in a container and a positive electrode on which the positive electrode active material is coated as a working electrode, a reference electrode, and a negative electrode as an auxiliary electrode. However, this method has the following problems.

First, there is a problem that results that do not match the electrode potential in an actual cell can be obtained. In general, a secondary battery includes an electrode assembly having a specific structure consisting of a positive electrode, a separator, and a negative electrode in a sealed case (can, pouch, etc.) in which an electrolyte is impregnated, and various other battery components are installed. Therefore, since the internal environment of the actual secondary battery shows a lot of differences from the conditions for the experiment, it exhibits a difference with the electrode potential in the experiment conditions performed under a very simplified condition. For example, to measure a potential similar to that of an actual cell, the distance between the positive electrode and the negative electrode should be reduced as much as possible, but this is not easy to realize in conventional experimental conditions.

Second, there is a problem in that the potential change of the positive electrode and the negative electrode during actual charge and discharge cannot be measured at the same time.

Third, there is a problem in that the manufactured battery must be completely disassembled in order to measure the electrode potential. In the case of performing periodic tests for the purpose of evaluating the quality of a mass produced battery, the complete disassembly of the battery may be time consuming and result in a change of the actual condition of the battery as described above, so that accurate results may be difficult to obtain.

Fourth, there is a problem that the measurement of the electrode potential is not easy in the state in which various experimental conditions for measuring various physical properties required for the battery are set. The secondary battery must satisfy various requirements such as high temperature safety and needle penetrating safety. It is required to measure the electrode potential under experimental conditions to confirm that the requirements are met.                         

Therefore, the conventional method for measuring the three-electrode-based electrode potential in relation to the secondary battery has a lot of problems, there is a high need for a technology that can solve these problems.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

Specifically, an object of the present invention is to measure the electrode potential of a secondary battery by a three-electrode measurement method, a reference electrode probe that can be used to accurately measure the electrode potential in the actual operating conditions of the battery by simply mounting without disassembling the battery To provide.

Another object of the present invention is to provide a method for easily measuring the electrode potential of a secondary battery using the reference electrode probe.

The reference electrode probe according to the present invention for achieving the above object is a reference electrode for measuring the three-electrode potential, an electrical insulating member that can be inserted into the through hole of the battery case and installed while maintaining the sealing, and the insulating member It consists of a conductive needle-like member penetrating vertically through the center of the projecting on the top and bottom surfaces.                     

The reference electrode probe according to the present invention is inserted into a through hole formed in a case of a secondary battery or an artificially formed through hole for measuring an electrode potential, thereby maintaining the configuration of the battery as it is, thereby maintaining a desired electrode potential. It can be measured. Therefore, the electrode potential in the actual operating state of the secondary battery can be measured quickly and accurately, and also under various experimental conditions.

The electrically insulating member is not particularly limited as long as it is an elastic material that is insulative to the battery case and can be in close contact with its through hole. For example, the polyethylene resin, polypropylene resin, polybutadiene resin, polystyrene resin, rubber (Natural rubber, various synthetic rubbers) and the like can be used.

The shape of the electrically insulating member may vary, and preferably, the lower end portion is tapered so as to be easily inserted into the through hole, and the portion in contact with the battery case is indented.

As described above, the needle member protrudes from the electrically insulating member while vertically penetrating the electrically insulating member, so that when the probe is installed in the electrical case to measure the electrode potential, the protruding lower end contacts the electrolyte. The protruding upper end serves as a terminal for electrical connection with the measuring device.

The material of the needle member is not particularly limited as long as the material is not reactive with the electrolyte or has a very low reactivity and has a conductivity. Specifically, the needle member should not be reactive with the electrolyte in the range of −2 V to 5 V, which is the operating potential of the battery.

The needle member itself may be made of a material that can be used as a reference electrode, and in some cases, may be separately installed by attaching or applying such a reference electrode material to a protruding lower end. Alternatively, only the lower end of the needle member may be made of the reference electrode material. Such a reference electrode material is not limited to the following, for example, platinum, gold, glassy carbon, lithium and the like can be used. Among them, platinum, gold, glassy carbon, etc. are easy to be made into the shape of the needle member, so it can be used by itself as a needle member without any additional additives. It can also be coated on.

The present invention also provides a method for measuring the electrode potential of the secondary battery using the reference electrode probe.

Electrode potential measurement method according to the present invention, the step of contacting the lower end of the protruding member of the needle member of the probe to the electrolyte by inserting the reference electrode probe into the through hole formed in the case of the battery or the through hole formed in the battery case And electrically connecting the protruding upper end of the probe to an external measuring device.

In some cases, it may further include the step of replenishing the electrolyte through the through hole to facilitate contact with the lower end of the needle member.

In general, the electrolyte is evaporated well, and as one preferred example, the reference electrode probe may be inserted into a through hole of the battery, and then the corresponding region may be coated with a separate sealing member. For example, the UV curable epoxy resin may be applied to a contact portion between the insulating member of the electrode probe and the through hole, and then cured to cover the sealing state.                     

In particular, the reference electrode probe according to the present invention may be preferably used for measuring the electrode potential of a rectangular secondary battery. Since the rectangular secondary battery is generally formed with an electrolyte injection hole, there is an advantage that can be used as a through hole for installation of the probe.

Hereinafter, although described with reference to the drawings according to an embodiment of the present invention, the scope of the present invention is not limited thereto.

1 is a schematic front view of a reference electrode probe according to an exemplary embodiment of the present invention. Referring to FIG. 1, the reference electrode probe 100 includes an electrically insulating member 200 and a conductive needle member 300. The needle member 300 includes an upper end portion 310 and a lower end portion 320 protruding upward and downward from the insulating member 200 in a state of penetrating the insulating member 200. The lower end of the needle member 320 is in contact with the electrolyte of the battery (not shown) when measuring the electrode potential, and the upper end 310 is electrically connected to an external device (not shown) for measuring the potential.

When the insulating member 200 is inserted into the through hole of the battery case 410 to measure the electrode potential, a recess 210 closely contacted with the insulating member 200 is formed in the middle, and a lower portion 220 inserted into the battery case 410 is provided. ) Is tapered downward. On the other hand, the upper portion 230 is formed in a relatively larger structure than the lower portion 220 to be in close contact with the battery case 410. In addition, the connecting portion 240 of the recess 210 and the lower part 220 has a gentle curve, so that when the reference electrode probe 100 is inserted into the battery case 410, the sealing is excellent and at the same time separated after measurement Is easy.

However, the reference electrode probe 100 of the present invention may be of various shapes, all of which should be construed as belonging to the scope of the present invention.

FIG. 2 illustrates one exemplary configuration for measuring electrode potential of a rectangular secondary battery using the reference electrode probe 100 of FIG. 1.

Referring to FIG. 2, a positive electrode terminal 420 and a negative electrode terminal are provided in a rectangular secondary battery 400 sealed with a case 410 in a state in which an electrode assembly (not shown) including an anode, a separator, and a cathode is impregnated with an electrolyte. 430 is formed at the top. In general, since the rectangular secondary battery 400 serves as a positive electrode terminal, the negative electrode terminal 430 is electrically insulated from the case 410 by the insulating member 440.

In order to measure the electrode potential, first, the sealing member (not shown) of the electrolyte injection part 450 of the battery 400 is removed and the electrolyte solution 460 is replenished, and then the reference electrode probe 100 is transferred to the electrolyte injection part. Insert in (450). When the reference electrode probe 100 is considerably larger than the electrolyte injection unit 450, the reference electrode probe 100 may be inserted after greatly extending the diameter of the through hole of the electrolyte injection unit 450.

By such insertion, the needle-like lower end portion 320 of the reference electrode probe 100 comes into contact with the electrolyte 460. In the inserted state, the reference electrode probe 100 is electrically insulated from the battery case 410 by the insulating member 200.

Thereafter, the reference electrode probe 100, the positive terminal 420, and the negative terminal 430 are electrically connected to the potential measuring device 500 to measure the potential of the target electrode. In some cases, the electrode potential may be measured after setting specific conditions such as measuring battery characteristics under high temperature conditions or measuring battery characteristics when penetrating through a bed.

As described above, the electrode potential probe of the present invention is easy to manufacture due to its simple structure, and can quickly and accurately measure the electrode potential in the actual state of the secondary battery, and can be measured under various experimental conditions.

Claims (10)

A three-electrode electrode potential reference electrode probe, comprising: an electrically insulating member that can be inserted into a through hole of a battery case and can be installed in a sealed state, and a top surface and a bottom surface vertically penetrating the center of the insulating member A reference electrode probe, comprising a conductive needle member protruding from the reference electrode. The method of claim 1, wherein the electrically insulating member is made of one or more materials selected from the group consisting of polyethylene resin, polypropylene resin, polybutadiene resin, polystyrene resin, and rubber (natural rubber, various synthetic rubber). A reference electrode probe. The reference electrode probe according to claim 1, wherein the electrically insulating member has a shape in which a lower end portion is tapered to facilitate insertion into a through hole, and a portion in contact with the battery case is indented. The reference electrode probe according to claim 1, wherein the needle member is made of platinum, gold or glassy carbon. The reference electrode probe according to claim 1, wherein the reference electrode material is attached or coated on the protruding lower end of the needle member, or only the protruding lower end of the needle member is made of the reference electrode material. Inserting the reference electrode probe according to claim 1 into a through hole preformed in the case of the battery or a through hole formed in the battery case, and contacting the protruding lower end of the needle member of the probe with an electrolyte solution, and protruding of the probe Electrode potential measurement method of a secondary battery comprising the step of electrically connecting the upper end with an external measuring device. The method of claim 6, further comprising replenishing electrolyte through the through hole to facilitate contact with the lower end of the needle member. The method of claim 6, wherein the reference electrode probe is inserted into the through hole of the battery, and then the corresponding portion is coated with a separate sealing member to secure the sealed state. The method of claim 6, wherein the secondary battery is a rectangular secondary battery. 7. The method of claim 6, wherein the through hole is an electrolyte injection hole.

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