Highly concentrated graphene oxide ink for facile 3D printing of supercapacitors

3D printing of functional energy storage devices is receiving escalating attention over the years due to the customizable manufacturing flexibility and imparted high areal and gravimetric energy density of three-dimensional structured devices, which contribute to the creation of numerous new opportunities for futuristic electronics. Graphene-based inks are ideal elements for the realization of 3D printed energy storage devices if the attractive intrinsic physiochemical properties of graphene could be preserved. However, it is still a great challenge to prepare uniformly dispersed graphene-based materials with desired rheological properties for 3D printing. Here we report a facile strategy for 3D printing of supercapacitors from a highly concentrated graphene oxide (GO) ink. The GO is properly dispersed and the ink fulfills the stringent rheological specifications for 3D printing. The printed GO electrode is functionalized with enhanced structural stability for proper reduction to graphene. The printed supercapacitors deliver the potential to linearly scale up in areal capacitance without jeopardizing the gravimetric capacitance when increasing printed layers. The results hold great promise for the construction of 3D structured energy storage devices that cater to the challenges from next-generation electronics.

Key materials and future perspective for aqueous rechargeable lithium-ion batteries

Aqueous rechargeable lithium-ion battery(ARLiB)is of specific importance due to the low-cost,environmentalfriendly properties.Recently,its energy denisty and cyclic life have been significantly enhanced,demonstarting the potential for real applications.The improvement on key materials of ARLiB,ranging from cathode,anode and electrolyte,can finally ameliorate coresponding performance of full cell.Hereon,the cathode materials of ARLiBs are summerized as spinel oxides,layered oxides,olivine polyanion compounds olivine and Prussian blue analogues,while anode materials are classified into vanadium-based,polyanion,titanium-based and organic ones.Meanwhile,the strategies for better aqueous electrolytes are discussed from the aspects of salt concentration,solvent and interface.In the last part,issues challenging the commercialization of ARLiBs are provided as well as the suggestions for future research and development.

SusMat:Materials innovation for sustainable development

A well-received conception of sustainability was formulated by the United Nations’Brundtland Commission in 1987 as a process of change in which exploitation of resources,direction of investments,orientation of technical development,and institutional transformation are all in harmony and enhance both current and future potential to meet human needs and aspirations.Though raised a long time back,fostering a balanced development for the human race to meet the demands of the present without compromising the ability of future generations is still a tremendous challenge.Especially with the world energy needs growth rate outstripping that of population growth,a discouraging situation has been installed that points toward quick depletion of available resources.Moreover,the rapid urbanization shift in developing countries hungering for energy to emulate the level reached in developed countries to bolster rapid urban development further accelerates world energy consumption.The situation is exacerbated today,and approximately 80%of the world’s energy is driven from fossil fuels regarded as the primary culprit for air pollution and greenhouse gases.This poses grievous threats not only to the health of human race causing rising hospital admission rates,chronic respiratory,and cardiovascular diseases,but also to the environment alike.