Flexible Micro-Sensor Packaging and Durability for Real-Time Monitoring of Vanadium Flow Batteries

Abstract

The reactions of vanadium redox flow batteries (VRFBs) are quite complex and the internal environment is strongly acidic. The internal voltage, current, temperature and flow distribution play a very important role in the performance of a VRFB. The VRFB, which was developed by our R&D team, encountered easy leakage of electrolytes during assembly. Additionally, the strongly acidic environment can easily cause aging or failure of these VRFBs and of the micro-sensor. Therefore, this research was aimed at the need for real-time micro-diagnosis inside the VRFB. The use of micro-electro-mechanical systems (MEMS) technology was proposed so as to develop a flexible, integrated (current, voltage, flow and temperature), micro-sensor, and a durability test was conducted after packaging. Further, we performed real-time monitoring of the VRFBs. The main finding was that the encapsulation contributed to the stability of the micro-sensor without any failure due to excessive flow impacting the sensor. In the end we successfully used a 3D printed package to protect the micro-sensor.