Discover the PAT series
The science of battery testing has reached the next level with the introduction of the PAT series.
What is the PAT series?
The PAT series is a new generation of battery test cells that feature a unique single-use concept, which raises the standard of lithium-ion (Li-ion) battery research. All test cells are built around the PAT-Core, which is a highly customizable single-use compartment for the test specimen. This series enables two- and three-electrode tests of Li-ion batteries.
All PAT series test cells are designed without sockets for direct cable connections. They must, therefore, be used with docking stations such as the PAT-Stand-1, PAT-Stand-16, or the temperature-controlled PAT-Chamber-16. Because the cable connections do not need to be renewed for each testing, the parallel battery tests enable the generation of more reliable test results with less effort and in a shorter period of time.
The PAT-Core is the heart of the PAT series
The first part of the PAT-Core is an insulation sleeve, which is made of polypropylene and is equipped with a built-in ring-shaped Li-reference electrode and a 260μm glass fiber separator. The insulation sleeve is pre-assembled under protective atmosphere at the EL-CELL® factory to ensure consistent quality for reproducible battery tests.
PAT-Core versions without a reference electrode or with a customized separator are available on request. As the current collectors, the upper and lower plungers are made of copper, aluminum, or stainless steel. This enables battery researchers to work exclusively with battery grade materials. Aluminum and copper plungers are single-use components, while the stainless steel plungers are reusable.
Different materials for your test case
The PAT-Core can be used with many different battery and capacitor types. The table below summarizes some of the most common test cases.
In general, when lithium metal is used as the negative electrode and when measuring half-cell impedances, we recommend sleeves with a built-in glass fiber separator rather than the thin technical separators such as Viledon and Celgard. Glass fiber is also the best choice when wettability is a potential issue (e.g. when using ionic liquids).
Good to know: The PAT-Core components
By default, the lower plunger serves as the positive current collector. It is available in different materials and in different “height numbers”. The proper plunger height must be chosen to ensure that the pre-assembled separator is not excessively bent during assembly of the PAT-Core. The proper plunger height number depends on both the thickness of the lower electrode and the thickness of the built-in separator. The following rules apply:
For a separator thickness less than 100µm
Height number = thickness of lower electrode (in µm) + 50
Height number = thickness of lower electrode (in µm) + half of the separator thickness (in µm) We supply lower plungers with height numbers between 50 and 800 in steps of 50. Example: If you are using an insulation sleeve with a 260µm glass fiber separator, together with a 90µm thick LCO cathode, then the above equation yields a height number of 90 + 260/2 = 220. The closest available height number is 200.
By default, the upper plunger serves as the negative current collector. Only one plunger height is available, but it will fit any thickness of the upper electrode up to 800µm. The upper plunger is available in different materials: stainless steel 1.4404, Al 99.5% and Cu 99.9%.
Spring force in relation to the upper electrode thickness:
Please note that the height of the upper electrode has an impact on the force applied by the spring on the cell stack. Different springs are available as spare components for the PAT series test cells; please refer to the corresponding manual.
The insulation sleeve is available with and without a ring-shaped lithium metal reference ring and with three different types of separators: a double-layered separator comprised of a 180 µm thick nonvowen PP cloth (Freudenberg FS 2226 E) and a 38 µm thick microporous UHMW-PE membrane (Lydall Solupor 5P09B), a 260µm borosilicate glass fiber separator (Whatman GF/A), and a 25µm nonwoven polyester separator pasted with Al2O3 (Freudenberg Viledon FS 3005-25).
PAT compatibility table
What is the right test / docking station for your PAT-Cell?