A Flexible Six-in-One Microsensor Embedded in a Vanadium Redox Flow Battery for Long-Term Monitoring

The vanadium redox flow battery (VRFB) can be used as a supporting technology for energy storage corresponding to wind and solar power generation. An aqueous vanadium compound solution can be used repeatedly. As the monomer is large, the flow uniformity of electrolytes in the battery is better, the service life is long, and the safety is better. Hence, large-scale electrical energy storage can be achieved. The instability and discontinuity of renewable energy can then be solved. If the VRFB precipitates in the channel, there will be a strong impact on the flow of vanadium electrolyte, and the channel could even be blocked as a result. The factors which influence its performance and life include electrical conductivity, voltage, current, temperature, electrolyte flow, and channel pressure. This study used micro-electro-mechanical systems (MEMS) technology to develop a flexible six-in-one microsensor which can be embedded in the VRFB for microscopic monitoring. The microsensor can perform real-time and simultaneous long-term monitoring of the physical parameters of VRFB, such as electrical conductivity, temperature, voltage, current, flow, and pressure to keep the VRFB system in the best operating condition.