Dilatometer

Measurement of charge-induced strain (expansion & shrinkage)

The dilatometer is a research grade instrument dedicated to the measurement of charge-induced strain (expansion and shrinkage) of electrodes down to the sub-micrometer range. The dilatometer  is particularly developed for the investigation of Li-ion battery and other insertion-type electrodes. It may be used in organic as well as aqueous electrolyte solutions.

The dilatometer is the result of more than 10 years? experience in that field. The heart of the device is an electrochemical cell hermetically tight against ambient atmosphere. The two electrodes inside are separated by a stiff glass frit that is fixed in position. The upper (working) electrode is sealed by means of a thin metal membrane through which any charge-induced height change is transmitted towards the sensor/load unit that is attached from top.

Two resolutions are offered:

- ECD-2-DL (PN: E-ECD-2DL): A high-resolution displacement transducer detects dimensional changes ranging from 20 nanometers up to 500 micrometers, during one and the same experiment that may last between a few seconds to many days. A simple weight serves to adjust the load on the working electrode. Its potential can either be controlled against the counter electrode (cell voltage control) or against an additional reference electrode.

- ECD-nano-DL(PN: E-ECD-N): The ECD-nano-DL electrochemical dilatometer with a resolution in the true nanometer range. This new development is fully compatible with the ECD-1, except for the sensor/load unit. With the new capacitive parallel-plate sensor system, the ECD-nano provides a much better resolution below 5 nm (against 50 nm for the ECD-1). We believe the high resolution of the ECD-nano-DL will open new areas of application to electrochemical dilatometry. For instance, quasi 2 dimensional electrode processes like the SEI formation in lithium-ion batteries, or the electrochemically driven growth of passivation layers on metal surfaces might become the subject of future dilatometric studies.The heart of the ECD-nano-DL is an electrochemical cell, hermetically tight against ambient atmosphere. The two electrodes inside are separated by a stiff glass frit that is fixed in position. The upper (working) electrode is sealed by means of a thin metal membrane, through which any charge-induced height change is transmitted towards the sensor/load unit above.

In Standard:

The ECD-nano-DL/ ECD-2-DL dilatometer equipped for aprotic electrochemistry (dilatometer cell, sensor, and sensor-controller with dc-voltage output [-10; +10] V). With integrated USB data logger. Construction materials in media contact are stainless steel and PEEK. The user has to provide all peripheral equipment like temperature chamber and potentiostat.

Upgrade Kit Aqueous:

The upgrade kit contains gold current collectors that replace the stainless steel current collectors, used otherwise .

Comparison

ECD-2-DL and ECD-nano-DL share the the same electrochemical test cell. They differ in the sensor/load unit that is attached on top of the working electrode. With the ECD-2-DL the electrode displacement is measured with an LVDT-sensor while the new ECD-nano-DL utilizes a capacitive parallel-plate sensor system. Still with its large-range LVDT sensor the ECD-1 is the right choice for test specimens with overall dimensional changes in the range of 5 to 500 µm. As the distinct advantage the new ECD-nano-DL provides a much better resolution below 5 nm (against 50 nm for the ECD-2-DL).