Multi-objective layout optimization of microstructures for redox flow battery using Galerkin decoupling technology and independent continuous mapping method

There is a trade-off relationship between ensuring sufficient active species for the electrode and minimizing energy dissipation in the energy storage systems. The imbalance of the trade-off relationship results in a large amount of accumulation of active species in the flow dead zone and localized high pressure around the microstructure. In order to solve this problem, a novel multi-objective two-dimensional (2D) negative porous electrode microstructure layout optimization method is proposed. First, a linear source term and a fluid–solid coupled boundary elements extraction method are defined, which ensure that species generation occurs exclusively at the fluid–solid contact elements. Second, the convection–diffusion equation portraying the transport and generation of species is addressed by making use of the Galerkin decoupling technology. Third, the parametric modeling architecture combining shape functions, Bezier curve, Carman–Kozeny permeability relations method, along with the filter functions permits continuous evolution of arbitrary microstructures on the Euler mesh based on independent continuous mapping method. Finally, the multi-objective optimization problem of minimizing the energy dissipation controlling fluid flow and maximizing the concentration of the generated species characterizing electrochemical reaction transformation is transformed into a single-objective optimization problem by using the weighted-sum method. A sensitivity analysis is carried out, and the optimized model is resolved by applying a genetic algorithm. Numerical results demonstrate that energy dissipation occupation ratio greater than 0.5 facilitates electrolyte flow through each microstructure, solves the localized high pressure around the microstructure and the aggregation of generated species in 2D porous electrodes, and promotes the collection of generated species in the tank. This paper offers guidance for optimizing the layout of electrode microstructure.