Liquid flow characteristics and mass transport in porous carbon electrodes for hydrogen-bromine flow batteries

In this thesis we study the effect of post-assembly compression of the liquid side electrode of the hydrogen-bromine redox flow battery, caused by moderate hydrogen pressure operation, on the performance characteristics of the electrode. We compare and contrast two common electrode materials for hydrogen-bromine redox flow batteries, carbon paper and carbon cloth. The study is divided into four main sections, each dealing with a specific aspect of the performance of the electrode. First, we study the relation between ohmic losses and pumping losses in the electrode as a function of its compression. Next, we study the characteristics of liquid flow through compressed electrodes. Then, we study the mass transfer characteristics of the electrodes expected in a battery cell at moderate hydrogen pressures. Finally, we study the interaction between electrode and flow field and its dependence on hydrogen pressure.