This　work　investigates　the　impact　of　stoichiometry　ratio　on　the　performance　of　a　unitized　regenerative　fuel　cell　using　a　two-phase,　non-isothermal　model.　Results　indicate　that　increasing　the　stoichiometry　ratio　improves　mass　transfer　and　water　discharge,　but　also　increases　pump　work.　Therefore,　the　performance　enhancement　rate　initially　increases　and　then　declines　with　higher　stoichiometry　ratios.　The　study　found　that　a　stoichiometry　ratio　of　1.5　achieves　the　maximum　net　output　power,　and　adjusts　the　highest　round-trip　energy　efficiency　during　high　levels　of　starvation.　©　2024　Science　Press.　All　rights　reserved.