Double-network thermocells with extraordinary toughness and boosted power density for continuous heat harvesting

•Double networks with a synergy effect are designed for high-performance thermocells•Stretchable thermocells show extraordinary toughness even higher than cartilages•Robust capable of loading high concentrations electrolytes•The thermocell reaches the highest-level power density in quasi-solid Thermocells have recently attracted increasing interest field Internet Things owing to their capacity continually wearable electronics by converting low-grade heat electricity. However, liquid face leakage risk electrolytes, while crosslinked physical encounter challenges poor mechanical properties and low densities. Inspired topologically entangled multi-networks muscles cartilages, this work designs double chemically address these challenges. This not only shows large stretchability, impressive strength, notch insensitivity, toughness, which is that but also supreme grade thermocells. We believe will change landscape benefit realization sustainable self-powered era internet things. hold great potential harvesting waste ubiquitous electronics, integration hampered electrolytes. Although some physically been introduced prepare leak-free thermocells, they easy break because extremely small fracture energies about 10 J m?2 limited output densities 0.01–0.06 mW K?2. Herein, study improving density. The stretchability 217%, strength 1,190 kPa, 2,770 m?2, boosted 0.61 It works stably when being sliced stretched. breaks limitations With rapidly global market things (IoT), demand reliable sources working as continuous mode mechanically adaptable dynamic human-machine interfaces.1Ray T.R. Choi J. Bandodkar A.J. Krishnan S. Gutruf P. Tian L. Ghaffari R. Rogers J.A. Bio-integrated systems: comprehensive review.Chem. Rev. 2019; 119: 5461-5533Crossref PubMed Scopus (487) Google Scholar,2Lopez Mackanic D.G. Cui Y. Bao Z. Designing polymers advanced battery chemistries.Nat. 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Meanwhile, synergistically enhances toughness.30Gong Also, ions, thermodynamic entropy difference thermopower.15Yu evaluated intermolecular interaction units UV spectra analysis.27Duan (aqueous K4Fe(CN)6 solution), its absorbance band shifts 218 215 nm addition AMPS 1B). location K3Fe(CN)6 solution) remains almost unchanged after 1C). indicate stronger means more bond 1D).27Duan P(AM-co-AMPS) easily rather Fe(CN)63?. enlarges ions’ mobility, i.e., Fe(CN)64– Fe(CN)63–.27Duan Finally, enlarged [Fe(CN)64–/Fe(CN)63–] beneficial boost coefficient).15Yu Besides, P(AM-co-AMPS), anionic causes osmotic pressure aqueous solution coiled chains polymerized can swelling.28Gong stretching states tailored varying mass ratio AM S1). Here, chose 2:1, was 27:1. ensures sufficient avoids rupture caused excessive swelling. addition, dissipate energy.23Zhao loosely offers stretchability. worthwhile note same unit network, pure polyelectrolyte network. reduce interfacial energy, provide them, increases toughness.31Zhao Laves phases formed binary blend AB4 Miktoarm star copolymer A-homopolymer.Macromolecules. 52: 1832-1842Crossref Fourier transform infrared (FTIR) spectrum freeze-drying hydrogel indicates successful synthesis S2). bands located 1,680–1,550 1,037 cm?1 belong amide group AMPS, respectively.32Lei A supramolecular biomimetic skin combining wide multiple sensory capabilities.Nat. 1134Crossref (286) After completing solvent exchange solutions, final double-network homogenous, transparent, stretchable, 1E). investigated influence concentration efficiency. 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