DE202016001912U1 - Gas-tight sample holder for electrical measurements - Google Patents

Abstract

Gas-tight sample holder for electrical measurements on liquid and solid samples, characterized in that it can be opened and closed by turning the upper (1) and lower (2) shell against each other without tools.

Description

The technical field to which the invention belongs

The invention belongs to the technical field of measurement of the ionic and electronic conductivity of solids and liquids, of electrical energy storage and conversion and of sensor technology.

The problem underlying the invention

The simplest and best known technique for contacting solid state electrodes is to clamp them between two metal electrodes. This is only useful for air-insensitive samples, as they have direct contact with the atmosphere. Even air-resistant samples can be damaged by the humidity. In this case, the sample must first be thoroughly dried, which is very time consuming. Furthermore, the sample can be damaged by assembly and transport, making reuse impossible. Air-sensitive samples can be packed in pouch cells. The tablet is welded between two plastic sheets and contacted with two metal strips. These metal contacts influence the electrical behavior of the cell and make the measurement results difficult to understand. The entire manufacturing process must take place in a glovebox, which is expensive, time-consuming and error-prone. Furthermore, pouch cells must be disposed of after a single experiment and the sample contained therein can not be recycled.

State of the art

Delacourt, C. et al (Measurement and Simulations of Electrochemical Impedance Spectroscopy of a Three Electrode Coin Cell Design for Li-Ion Cell Testing) describes a coin-like test cell, in which three electrodes (measuring, counter, and reference electrode) are performed. The opposing electrodes also have a small opening for introducing an electrolyte. This sample holder is used in electrochemical impedance spectroscopy for the testing of Li-ion cells. The connection of the two half-shells is made by pressing. This is already a finished disposable Li-ion prototype obtained by modifying an existing button cell. This sample holder is only suitable for liquid electrolytes, can only be closed with special tools and can only be used once.

DE69227176 T2 shows a liquid conductivity cell, consisting of a container (insulating ceramic) with integrated electrodes (conductive ceramic) and lead wires, which has a high corrosion resistance and mechanical strength and can be used under high pressure and high temperature conditions. Between container and electrodes, a high density is achieved, the compound is therefore gas and liquid-tight. To seal the vessel may include a plug are used. The application are liquid samples, the handling (plug) in a glovebox is difficult.

Novocontrol Technologies describes on its homepage ( http://www.novocontrol.de/html/index_sample_cells.htm ) a gas-tight, sealed disposable sample body for liquid samples used in the context of impedance spectroscopy. This is not suitable for solids, not reusable and contains metallic springs, which have high inductances and thus falsify the measurement result.

Szyplowska, A. et al (Application of a Coaxial-Like Sensor for Impedance Spectroscopy Measurements of Selected Low-Conductivity Liquids) use a coaxial-like sensor for the evaluation of liquid samples in the context of impedance spectroscopy. The sensor consists of 7 steel bars embedded in the lid and a common outer electrode, which is placed tightly on a container. In addition to an ergonomic, easy-to-clean sensor design, emphasis was also placed on universal applicability (use on different measuring devices). This sensor is hung directly into a vessel containing the liquid to be tested to measure its conductivity, but is not intended to incorporate a liquid or solid sample directly into an electrically shielded and temperature controlled impedance measurement system.

The invention for which protection is sought in the protection claims

The present invention relates to a gas-tight, reusable sample holder for liquid and solid samples, which makes it possible to perform precise electrical measurements, such as impedance spectroscopy, cyclic voltammetry, electrical charging and discharging. The sample holder consists of two shells with integrated electrodes and contact bushings, which are gas-tightly interconnected by means of screw caps. Due to the materials used, the sample holder behaves electrically neutral and can be opened and closed without tools.

The invention consists of two shells made of electrically insulating material with gas-tight contact bushings for Porbenkontaktierung. The device is opened and closed by the two Bowls are twisted against each other. The elasticity of the material ensures tight closure and allows opening and closing in the glove box without tools. The design ensures that the sample is not electrically affected over a wide frequency and temperature range. The sample holder works without seals, springs and screws. The compact dimensions and the good thermal conductivity make it possible to install the device in a cryostat for temperature-controlled measurements.

Advantageous effects of the invention with reference to the state of the art mentioned in the application

Comparing with the technique of Pouch Cells, the setup of the experiment is less time and material consuming. The measurement results are easier to understand and reproducible. The sample holder can be loaded and unloaded without tools inside a glovebox. The handling can be done after a short briefing, while the production of Pouch Cells requires highly qualified and experienced personnel. The present invention can be reused many times and causes much less waste than conventional techniques. Experiments with air-sensitive samples are as easy to perform as with insensitive.

Industrial Applicability

The invention finds application in the development of accumulators, fuel cells and sensors in the automotive industry, consumer electronics and university research.

embodiment

An embodiment of the invention will be described with reference to 1 and 2 explained.

LIST OF REFERENCE NUMBERS

1

Upper shell

2

Lower shell

3

Upper electrode

4

Lower electrode

5

inner thread

6

external thread

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69227176 T2 [0004]

Cited non-patent literature

• Delacourt, C. et al (Measurement and Simulations of Electrochemical Impedance Spectroscopy of a Three Electrode Coin Cell Design for Li-Ion Cell Testing) [0003]
• http://www.novocontrol.de/html/index_sample_cells.htm [0005]
• Szyplowska, A. et al (Application of a Coaxial-Like Sensor for Impedance Spectroscopy Measurements of Selected Low-Conductivity Liquids) [0006]

Claims (3)

Gas-tight sample holder for electrical measurements on liquid and solid samples, characterized in that it is produced by twisting the upper ( 1 ) and lower ( 2 ) Shell can be opened and closed against each other without tools. Sample holder according to claim 1, characterized in that the gas-tightness alone by the elasticity of the materials used of the components ( 1 ) and ( 2 ) by thread between female thread ( 5 ) and external thread ( 6 ) is guaranteed without seals, springs and screws. Sample holder according to one of the preceding claims, characterized in that the electrical contacting of the sample through the components ( 1 ) and ( 2 ) incorporated metal electrodes ( 3 ) and ( 4 ) without additional springs and screws.

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