Wet‐Spun Superelastic Graphene Aerogel Millispheres with Group Effect

Abstract

Graphene aerogel has attracted great attention due to its unique properties, such as ultralow density, superelasticity, and high specific surface area. It shows huge potential in energy devices, high-performance pressure sensors, contaminates adsorbents, and electromagnetic wave absorbing materials. However, there still remain some challenges to further promote the development and real application of graphene aerogel including cost-effective scalable fabrication and miniaturization with group effect. This study shows millimeter-scale superelastic graphene aerogel spheres (GSs) with group effect and multifunctionality. The GSs are continuously fabricated on a large scale by wet spinning of graphene oxide liquid crystals followed by facile drying and thermal annealing. Such GS has an unusual core-shell structure with excellent elasticity and specific strength. Significantly, both horizontally and vertically grouped spheres exhibit superelasticity comparable to individual spheres, enabling it to fully recover at 95% strain, and even after 1000 compressive cycles at 70% strain, paving the way to wide applications such as pressure-elastic and adsorbing materials. The GS shows a press-fly behavior with an extremely high jump velocity up to 1.2 m s . For the first time, both free and oil-adsorbed GSs are remotely manipulated on water by electrostatic charge due to their ultralow density and hydrophobic properties.

3D Thermally Cross‐Linked Graphene Aerogel–Enhanced Silicone Rubber Elastomer as Thermal Interface Material

“…The pore structures were further investigated by mercury intrusion tests and the results were listed in Table S2 (Supporting Information). All the samples show high porosity (81.37–93.52%) and low bulk density . With the increase of heat‐treatment temperature, the porosity only shows slight decrease, which is in accordance with the scanning electron microscope (SEM) images in Figure a–c.…”

Graphene: A Cathode Material of Choice for Aluminum‐Ion Batteries

“…These channels are produced in situ by the escape pathways of the gaseous byproducts when decomposition of the functional groups of graphene oxide occurs during hightemperature annealing. [49] In abid to enhance the volumetric energy density of AIB, Huang et al developed high tap density free-standing monolithic nanoporous graphene foam by hard-templating method. More strikingly,t he graphene cathode also sustains ultralong life of aq uarter of am illion cycles with ac apacity value of 110 mAh g À1 at an incredibly high current rate of 100 Ag À1 (Figure 3f).…”

“…Similarly,m illimeter-sized superelastic graphene aerogel spheres,s ynthesized by wet spinning and high-temperature processes,d eliver as pecific capacity of 85 mAh g À1 at acurrent density of 5Ag À1 with 90 %capacity retention over 8000 cycles. [49] In abid to enhance the volumetric energy density of AIB, Huang et al developed high tap density free-standing monolithic nanoporous graphene foam by hard-templating method. [50] This high density (ca.…”

“…[36] In contrast, the maximum tolerance for current is 0.1 Ag À1 for the rest of the cathodes essentially signifying very low power output. [11,36,37,43,46,47,49,50] These unmatched traits of graphene will be immensely advantageous for achieving highly durable,high energy and power density Al-ion batteries. [36] In fact, unlike all other cathodes,a ll the graphene cathodes demonstrated high Coulombic efficiency (> 95 %) since beginning of cycling with excellent capacity retention rate (> 90 %).…”

“…[36] In fact, unlike all other cathodes,a ll the graphene cathodes demonstrated high Coulombic efficiency (> 95 %) since beginning of cycling with excellent capacity retention rate (> 90 %). [11,36,37,43,46,47,49,50] These unmatched traits of graphene will be immensely advantageous for achieving highly durable,high energy and power density Al-ion batteries.…”