Wearable self-powered systems integrated with energy conversion and storage devices such as solar-charging power units arouse widespread concerns in scientific and industrial realms.However,their applications are hamp...Wearable self-powered systems integrated with energy conversion and storage devices such as solar-charging power units arouse widespread concerns in scientific and industrial realms.However,their applications are hampered by the restrictions of unbefitting size matching between integrated modules,limited tolerance to the variation of input current,reliability,and safety issues.Herein,flexible solar-charging self-powered units based on printed Zn-ion hybrid micro-capacitor as the energy storage module is developed.Unique 3D micro-/nano-architecture of the biomass kelp-carbon combined with multivalent ion(Zn2+)storage endows the aqueous Zn-ion hybrid capacitor with high specific capacity(196.7 mAh g^−1 at 0.1 A g^−1).By employing an in-plane asymmetric printing technique,the fabricated quasi-solid-state Zn-ion hybrid microcapacitors exhibit high rate,long life and energy density up to 8.2μWh cm^−2.After integrating the micro-capacitor with organic solar cells,the derived self-powered system presents outstanding energy conversion/storage efficiency(ηoverall=17.8%),solar-charging cyclic stability(95%after 100 cycles),wide current tolerance,and good mechanical flexibility.Such portable,wearable,and green integrated units offer new insights into design of advanced self-powered systems toward the goal of developing highly safe,economic,stable,and long-life smart wearable electronics.展开更多
Dried kelp is one of the most important Japanese foods mainly used as base ingredient. Holdfasts, or rhizoids, of kelp are usually discarded, as rocks, shells, ropes and other contaminants are entangled among them. Th...Dried kelp is one of the most important Japanese foods mainly used as base ingredient. Holdfasts, or rhizoids, of kelp are usually discarded, as rocks, shells, ropes and other contaminants are entangled among them. The purpose of the present study was to examine whether the preparation of activated carbon from holdfasts of <em>Saccharina japonica</em>, a popular kelp harvested in Japan, is possible by a chemical activation technique utilizing zinc chloride, and to study the influence of the process parameters, such as carbonization temperature and the composition of the activator. Under the examined experimental conditions, maximum specific surface area of 1.7 × 10<sup>3</sup> m<sup>2</sup>/g, larger than that of a commercial activated carbon, was observed at 600℃ and the zinc chloride composition of 75 mass%.展开更多
基金the National Natural Science Foundation of Hubei Province(Grant No.2019CFB110)the fund of the Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials(Grant No.1-KF-2019).
文摘Wearable self-powered systems integrated with energy conversion and storage devices such as solar-charging power units arouse widespread concerns in scientific and industrial realms.However,their applications are hampered by the restrictions of unbefitting size matching between integrated modules,limited tolerance to the variation of input current,reliability,and safety issues.Herein,flexible solar-charging self-powered units based on printed Zn-ion hybrid micro-capacitor as the energy storage module is developed.Unique 3D micro-/nano-architecture of the biomass kelp-carbon combined with multivalent ion(Zn2+)storage endows the aqueous Zn-ion hybrid capacitor with high specific capacity(196.7 mAh g^−1 at 0.1 A g^−1).By employing an in-plane asymmetric printing technique,the fabricated quasi-solid-state Zn-ion hybrid microcapacitors exhibit high rate,long life and energy density up to 8.2μWh cm^−2.After integrating the micro-capacitor with organic solar cells,the derived self-powered system presents outstanding energy conversion/storage efficiency(ηoverall=17.8%),solar-charging cyclic stability(95%after 100 cycles),wide current tolerance,and good mechanical flexibility.Such portable,wearable,and green integrated units offer new insights into design of advanced self-powered systems toward the goal of developing highly safe,economic,stable,and long-life smart wearable electronics.
文摘Dried kelp is one of the most important Japanese foods mainly used as base ingredient. Holdfasts, or rhizoids, of kelp are usually discarded, as rocks, shells, ropes and other contaminants are entangled among them. The purpose of the present study was to examine whether the preparation of activated carbon from holdfasts of <em>Saccharina japonica</em>, a popular kelp harvested in Japan, is possible by a chemical activation technique utilizing zinc chloride, and to study the influence of the process parameters, such as carbonization temperature and the composition of the activator. Under the examined experimental conditions, maximum specific surface area of 1.7 × 10<sup>3</sup> m<sup>2</sup>/g, larger than that of a commercial activated carbon, was observed at 600℃ and the zinc chloride composition of 75 mass%.
