• Uhlig, Lisa Maria
• Gupta, Gaurav
• Germer, Wiebke
• Satola, Barbara
• Nagappan, Nambi Krishnan
• Schillert, Leif-Arvid

Abstract

<jats:title>Abstract</jats:title><jats:p>Bipolar plates and graphite felt electrodes were thermally fused to one single component via a newly developed electro-welding process. A dropwise arrangement of the polymeric binder led to mechanically stable bonding and was documented by X-ray micro-computed tomography. Electrical conductivity of the fused components was achieved without any conductive filler and electro-welded samples show lower resistance values than unbonded ones at the same graphite felt electrode compression of 5 % in ex situ electrical conductivity measurements. Applicability was demonstrated in situ in a 2-cell vanadium redox flow battery stack operated at a graphite felt electrode compression rate of 5 % only. Obtained energy efficiencies of the battery are at least equal or even higher compared to state of the art vanadium redox flow battery with unbonded components at 20 % graphite felt electrode compression. Composite components will simplify stack assembly and their increased electrode porosity during operation is expected to reduce pressure drop and to increase overall system efficiency.</jats:p>

Topics

• impedance spectroscopy
• tomography
• composite
• porosity
• electrical conductivity
• vanadium