Computational study of effects of contact resistance on a large‐scale vanadium redox flow battery stack. (5th March 2019)

• Record Type: Journal Article
• Authors: Jung, Seunghun; Choi, Byungchul; Park, Suhan; Lee, Dong‐Weon; Kim, Young‐Bae; Kim, Soowhan
• Is Part Of: International journal of energy research. Volume 43:Number 6(2019)
• Page Start: 2343
• Page End: 2360
• Publication Date: 2019-03-05
• Subjects: contact resistance -- modeling -- redox flow battery -- vanadium; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.4453
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: Computational models are developed to allow for a deeper understanding of design factors that affect the lifetime of a vanadium redox flow battery (VRFB) stack, particularly related with the contact‐resistance issue of end cells in a large‐scale stack. A simplified microcontact‐resistance model and a physics‐based macrocontact‐resistance model are constructed to investigate the effect of contact resistance on the performance and longevity of VRFB stacks. A microcontact‐resistance model predicts significant heat accumulation in the current‐collector plate that can result in irreversible damage of plastic materials and an electrical‐voltage loss if the contact resistance is not properly engineered in the stack design. Furthermore, the physics‐based macrocontact‐resistance model investigates abrupt voltage and current distortion in the bipolar plate that is in imperfect contact with the current collector; this results in the local corrosion of the bipolar plate. To ensure a long lifetime of VRFBs, a stack design with minimal contact resistance (less than 0.1 Ω cm 2 ) is required. The structural design of the endplate as well as the selection of a high‐stiffness material is critical to mitigate the bending issue and reduce contact resistance. Abstract : First computational analysis of the contact resistance between the current collector (CC) and the end bipolar plate (EBP) of a kW‐scale RFB stack. A performance loss, such as an additional voltage loss due to the contact resistance between the CC and EBP, was found. Degradation modes by an irreversible plastic damage or localized corrosion of bipolar plates owing to improper contact resistance are proposed.