Computational insights of bubble evolutions in water electrolysis

Water electrolysis is a pivotal technology for enabling the green hydrogen economy, though its efficiency remains substantially limited by the dynamics of bubble evolution. This review comprehensively discusses recent advances and the critical role of computational simulations in elucidating the mechanisms of multiscale bubble evolutions during electrolysis. We begin by outlining the governing mechanisms and fundamental theories underlying the evolution of both individual and multiple bubbles. The core discussion is then divided into two domains: molecular-scale simulations, which reveal how nanoscale behaviors—such as nucleation, growth, stability, and detachment—are influenced by electrode properties and operational conditions; and continuum-scale simulations, which investigate bubble growth, stability, coalescence, and migration within porous transport layers and real electrolyzer configurations, highlighting key interactions between multiphase flow and mass transfer. Finally, we discuss persistent challenges in predictive multiscale modeling of bubble evolutions in water electrolysis under practical operating environments and propose promising directions for future research. • Outlines typical behaviors and underlying physical mechanisms of bubbles in water electrolysis. • Summarizes recent advances and physical insights from molecular and continuum simulations of bubble dynamics. • Identifies challenges and future directions in predictive multiscale modeling for bubbles in water electrolysis.