Hydrogel　thermocells　possess　great　potential　in　the　energy　conversion　field　as　they　directly　absorb　waste　heat　from　the　environment　to　drive　redox　reactions　for　continuous　electricity　generation.　However,　achieving　high　toughness　and　good　elasticity　simultaneously　in　hydrogel　thermocells　remains　a　challenge　because　of　the　inherent　contradiction　of　energy　dissipation　mechanisms,　severely　limiting　their　practical　applications　and　lifespan.　To　address　this,　a　skin-like　hydrogel　network　with　a　highly　dense　interwoven　network　is　developed　to　construct　hydrogel　thermocells　with　good　elasticity　and　high　toughness.　The　dense　network　structure　can　effectively　disperse　the　stress　and　hinder　crack　propagation,　thus　breaking　the　contradiction　between　high　toughness　and　good　elasticity.　The　thermocell　realizes　a　toughness　of　460　J　m−2　while　reaching　an　elastic　limit　strain　of　350　%,　far　exceeding　the　elasticity　of　previous　stretchable　hydrogel　thermocells.　Meanwhile,　it　exhibits　ultra-low　hysteresis　and　excellent　fatigue　resistance　under　tensile　and　compressive　cyclic　loads.　Moreover,　the　thermocell　can　work　stably　over　long　periods,　enabling　stable　voltage　output　even　under　compression,　bending,　and　stretching.　In　addition,　the　thermocell　can　power　the　LED　lamp　and　calculator,　and　can　also　be　connected　in　series　to　form　large　arrays,　thus　rendering　it　an　ideal　power　source　for　wearable　devices.　©　2024　Elsevier　B.V.