The life cycle of lithium-ion batteries in electrically powered vehicles is closely related to the adhesion strength between the substrate and the electrode coating. Testing the adhesion strength facilitates prediction of the mechanical bond prior to actually being used.
Image Credit: ZwickRoell GmbH Co. KG
An ideal solution includes an AllroundLine materials testing machine plus a special test device, one that is readily available from ZwickRoell.
The strength of the bond between the current collector and coating can be identified via a tensile test. This generates accurate information relative to the mechanical strength of the electrode coating, specifically its adhesion to the current collector, and regarding the quality of the mechanical joint.
The goal is to determine a definitive relationship between the process parameters, the materials, and the electrochemical activity in the battery. When preparing the Z-direction tensile test, an application of special double-sided adhesive tape to parallel test platens is carried out.
Image Credit: ZwickRoell GmbH Co. KG
Having been previously trimmed to size, the electrode is then situated between the platens and securely affixed beneath a defined pre-load by means of the adhesive tapes. To establish adhesion strength, the peel test is repeated until the coating pulls away from the current collector.
The electrode separates from the substrate in a series of pulses during measurement of separation behavior. The high measured-value acquisition rate (2,000 Hz) of the testControl II and control electronics enables well-defined recording and display of these force peaks.
AllroundLine's high stiffness and precision crosshead guidance significantly reduce unwanted mechanical influences on the specimen, while thanks to the use of a Hiperface motor feedback system, crosshead resolution goes beyond the values usually available by a factor of 2.
Other highlights of the test resolution facilitated by AllroundLine plus testControl II include excellent measurement reproducibility, return speeds exceeding the nominal speed and superb constant-speed characteristics, even at the lowest speeds.
AllroundLine is optimized for use in laboratories with demanding testing applications subject to constant fluctuations.
The presence of two test areas facilitates the immediate utilization of two alternative test applications, saving reconfiguration time and supporting test result reproducibility.
The pliable adapter system, integrated T-slotted platforms and large test areas enable the use of large-scale, intricate test arrangements, while the extensive storage system means that all test fixtures are always readily available.
AllroundLine offer the user access to all safety requirements legally prescribed and contained in the EC Machinery Directive.
Image Credit: ZwickRoell GmbH Co. KG
This information has been sourced, reviewed and adapted from materials provided by ZwickRoell GmbH Co. KG.
For more information on this source, please visit ZwickRoell GmbH Co. KG