The design of power supply systems for wearable appli-cations requires both flexibility and durability.Thermoelectrochemical cells(TECs)with large Seebeck coefficient can efficiently convert low-grade heat into electricity,thus having attracted considerable attention in recent years.Utilizing hydrogel electrolyte essentially addresses the electrolyte leakage and complicated packaging issues existing in conventional liquid-based TECs,which well satisfies the need for flex-ibility.Whereas,the concern of mechanical robustness to ensure stable energy output remains yet to be addressed.Herein,a flexible quasi-solid-state TEC is proposed based on the rational design of a hydrogel electrolyte,of which the thermogalvanic effect and mechanical robust-ness are simultaneously regulated via the multivalent ions of a redox couple.The introduced redox ions not only endow the hydrogel with excellent heat-to-electricity conversion capability,but also act as ionic crosslinks to afford a dual-crosslinked structure,resulting in reversible bonds for effective energy dissipation.The optimized TEC exhibits a high Seebeck coefficient of 1.43 mV K-1 and a significantly improved fracture toughness of 3555 J m-2,thereby can maintain a stable thermoelectrochemical performance against various harsh mechanical stimuli.This study reveals the high potential of the quasi-solid-state TEC as a flexible and durable energy supply system for wearable applications.