Convertible hydrogel supercapacitors have emerged as promising energy storage devices in switches,diodes,and transistors.However,inherent weaknesses in ionic conductivity,mechanical properties,and water retention of h...Convertible hydrogel supercapacitors have emerged as promising energy storage devices in switches,diodes,and transistors.However,inherent weaknesses in ionic conductivity,mechanical properties,and water retention of hydrogel electrolytes seriously hinder their development.Inspired by the hardness conversion of sea cucumber skin,a conductivity and mechanics dual-tunable salt gel electrolyte is successfully designed.The salt gel presents a reversible switching of conductors-insulators and a mechanical regulation between softness and hardness via the dissolution-crystallization transition of sodium acetate trihydrate(SAT).Meanwhile,the salt gels spontaneously grow a layer of“armor”through saturated phase-change salt crystals effectively reducing water evaporation of hydrogel electrolytes.Furthermore,this phase-change soft-rigid conversion strategy will expand the capabilities of gel-based flexible supercapacitors(area capacitance:258.6 mF cm^(-2)),and the capacitance retention rate could still reach 86.9%after 3000 cycles at high temperatures.Moreover,the salt gel supercapacitor is potentially used in over-heat alarm systems.It is anticipated that the strategy of conductivity and mechanics of dual-tunable salt gel would provide a new perspective on the development of energy storage devices,wearable electronics,and flexible robots.展开更多
Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties compos...Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties composites based on hydrogels and ceramic nanofiller.The wide tunable range of Young’s modulus(27.3 kPa to 3.5 GPa)and ultimate stress(173 kPa to 102 MPa)can be achieved by combining solvent absorption and evaporation process with platelets reinforcement effect.Additionally,a large fracture toughness(∼32,000 J m^(-2))is obtained as a result of the nacre-liked“brick and mortar”structure introduced by shear force during fabrication.The superior flexibility and designability of this material were demonstrated via actuators,portable structure,and metamaterials.Above all,this study provides a new thought to fabricate tough materials with post-tunable mechanical properties.展开更多
基金National Natural Science Foundation of China(No.52303144)Department of Science and Technology of Jilin Province(Nos YDZJ202301ZYTS295 and 20230508188RC)。
文摘Convertible hydrogel supercapacitors have emerged as promising energy storage devices in switches,diodes,and transistors.However,inherent weaknesses in ionic conductivity,mechanical properties,and water retention of hydrogel electrolytes seriously hinder their development.Inspired by the hardness conversion of sea cucumber skin,a conductivity and mechanics dual-tunable salt gel electrolyte is successfully designed.The salt gel presents a reversible switching of conductors-insulators and a mechanical regulation between softness and hardness via the dissolution-crystallization transition of sodium acetate trihydrate(SAT).Meanwhile,the salt gels spontaneously grow a layer of“armor”through saturated phase-change salt crystals effectively reducing water evaporation of hydrogel electrolytes.Furthermore,this phase-change soft-rigid conversion strategy will expand the capabilities of gel-based flexible supercapacitors(area capacitance:258.6 mF cm^(-2)),and the capacitance retention rate could still reach 86.9%after 3000 cycles at high temperatures.Moreover,the salt gel supercapacitor is potentially used in over-heat alarm systems.It is anticipated that the strategy of conductivity and mechanics of dual-tunable salt gel would provide a new perspective on the development of energy storage devices,wearable electronics,and flexible robots.
基金financial support provided by the Guangdong Provincial Department of Science and Technology (KeyArea Research and Development Program of Guangdong Province) under the grant 2020B090923002Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project (HZQB-KCZYB-2020030)+2 种基金National Key R&D Program of China (Project No. 2017YFA0204403)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Centerthe JLFS-RGC-joint Laboratory Funding Scheme (Reference No. JLFS/E103/18)
文摘Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties composites based on hydrogels and ceramic nanofiller.The wide tunable range of Young’s modulus(27.3 kPa to 3.5 GPa)and ultimate stress(173 kPa to 102 MPa)can be achieved by combining solvent absorption and evaporation process with platelets reinforcement effect.Additionally,a large fracture toughness(∼32,000 J m^(-2))is obtained as a result of the nacre-liked“brick and mortar”structure introduced by shear force during fabrication.The superior flexibility and designability of this material were demonstrated via actuators,portable structure,and metamaterials.Above all,this study provides a new thought to fabricate tough materials with post-tunable mechanical properties.
