A capacity-recoverable zinc-ion micro-supercapacitor with high energy and power density is developed.

By an ice-template method, in this work we realized an ambient pressure dried graphene aerogel (ADGA) with superelasticity and multifunctionality by using ordinary instruments.

To investigate the e¡ects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (C maxe ; J day À1 ) and the speci¢c growth rate in terms of energy (SGRe; % day À1 ) in animals of three body sizes (mean AE SE)^large (134.0 AE 3.5 g), medium (73.6 AE 2.2 g) and small (36.5 AE 1.2 g)^were determined at water temperatures of 10, 15, 20, 25 and 30 1C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20 1C. This trend, however, was not apparent at 25 and 30 1C, which could be in£uenced by aestivation. High water temperatures (above 20 1C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15 1C, and body size seemed to have a slight e¡ect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3^139.3 g) was 24.5 À25.5 1C, while that for small animals (28.94 0.7 g) was between 25.5 and 30.5 1C. These values are higher than previous reports; di¡erences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons.

The inherently formed liquid crystals (LCs) of graphene oxide (GO) in aqueous dispersions severely restrict the fabrication of large-size and structure-intact graphene aerogel bulk by an industry-applicable method. Herein, by developing a surfactant-foaming sol−gel method to effectively disrupt and reconstruct the inherent GO LCs via microbubbles as templates, we achieve the large-size and structure-intact graphene hydrogel bulk (GHB). After simple freezing and air-drying, the resulting graphene aerogel bulk (GAB) with a structure-intact size of about 1 m 2 exhibits a superelasticity of up to 99% compressive strain, ultralow density of 2.8 mg cm −3 , and quick solar-thermal conversion ability. The modified GAB (GABTP) shows a high decomposition temperature (T max ) of 735 °C in air and a low heat storage capacity. These excellent performances make the GABs suitable for many practical applications, as proven in this work, including as high compressive force absorbers, high absorption materials for oils or dangerous solvents, superior solar-thermal management materials for rapid heater or controlled shelter, and high-efficiency fire-resistant and thermal insulation materials. The whole preparation process is easily scalable and cost-effective for mass production of structureintact multifunctional graphene aerogel bulk toward practical applications.

At relatively low temperature (e.g, -30 oC), most flexible supercapacitors that work well at room temperature will lose their stretchability due to the poor cold intolerance of conventional electrolytes and...

In this work, a new type of hybrid energy storage device is constructed by combining the zinc-ion supercapacitor and zinc–air battery in mild electrolyte. Reduced graphene oxide with rich defects, large surface area, and abundant oxygen-containing functional groups is used as active material, which exhibits two kinds of charge storage mechanisms of capacitor and battery simultaneously. Apart from the physical adsorption/desorption of anions on the surface of graphene, the zinc ions in electrolyte will be electrochemically adsorbed/desorbed onto the oxygen-containing groups of graphene during the charge/discharge process, contributing extra capacitance to the device. Moreover, the defects in graphene will further improve the electrochemical performance of the energy storage device via catalyzing the oxygen reduction reaction with exposure to air. Consequently, the synergistic effect leads to a record high capacitance of 370.8 F g–1 at a current density of 0.1 A g–1, which is higher than that of zinc-ion supercapacitors reported previously. Furthermore, the hybrid device exhibits a superior cycling stability with 94.5% capacitance retention even after 10000 charge/discharge cycles at a high current density of 5 A g–1. Interestingly, the developed hybrid device can be self-charging automatically after the power is exhausted in the ambient atmosphere. Other electrode materials, such as carbon nanotube paper, are also used to build a hybrid device to verify the feasibility of this strategy. This facile, green, and convenient strategy provides new insight for developing a high performance storage device, showing great application prospect in other hybrid energy storage devices in mild electrolyte.

An aqueous rechargeable micro-Zn–MnO2 battery with high voltage output and good cycling performance is fabricated via simple laser-assisted machining and electrochemical deposition technology.

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