Phase-Field Simulation of Dendrite Growth in Porous Electrodes of Zinc-Based Flow Batteries

Zinc-based flow batteries (ZFBs) are promising candidates for large-scale renewable energy storage, yet zinc dendrite growth severely limits their long-cycle stability and practical deployment. To address this critical challenge, this study employs a nonlinear phase-field model to systematically investigate the dynamic evolution of zinc dendrites in the porous electrodes of ZFBs, focusing on the regulatory effects of electrolyte flow velocity, electrochemical reaction constant ( L η , characterizing exchange current density), and carbon fiber arrangement on dendrite morphology, deposition efficiency, and growth kinetics. The simulation results show that dendrite growth in porous electrodes undergoes three stages: initial uniform deposition, middle-stage anisotropic bridging, and late-stage continuous network formation. Lower electrochemical reaction constant yields regular dendrites but slow charging, which can be improved by optimizing electrolyte flow velocity; higher electrochemical reaction constant accelerates charging but induces disordered dendrites, which is mitigated via pulse charging. Disordered carbon fiber arrangement exacerbates flow/concentration inhomogeneity and dendrite abnormal growth, while uniform arrangement suppresses disordered growth. This work fills the gap in phase-field simulation of dendrites in porous electrodes and provides targeted regulatory strategies, offering theoretical support for enhancing the long-cycle safety and stability of ZFBs in large-scale energy storage applications.