The hottest porous graphene accelerates the energy

2022-08-17
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Porous graphene accelerates the energy revolution

nano materials are a kind of potential materials in the eyes of scientists, but for general manufacturers, especially in the battery industry, the existing batteries cannot meet the two conditions of high energy density and high power density at the same time, but nano materials have this possibility. Now researchers have made preliminary materials, This is graphene Nb2O5 nanocomposite [sun et al., Science (2017) 356, 599]

nanostructured energy storage materials are limited by ultra-thin electrodes and low mass loads. However, researchers from the University of California, Hunan University, and King's University of Saudi Arabia prepared three-dimensional porous graphene complexes, which, after entering Nb2O5 in 2017, behaved like nano conductive scaffolds, overcoming the above problems. The interconnected graphene structure provides a framework for electron transport, while the adjustable pores allow the rapid movement of ions

"by systematically designing the porosity in the graphene backbone, the optimized charge transfer of the composite structure has the ability of high capacity and high current density," Duan said. "We have made great breakthroughs in the high-performance electrode materials of batteries."

The application of porous graphene framework in supercapacitors has been reported. Large area is an advantage, but until now, the diffusion limitation of thick electrodes has proved to be very challenging. In the new material, when the mass load is mg/cm2, the combination of interpenetrating electron and ion transport paths provides a higher charge discharge rate

duan explained, "in thicker electrodes, the mass transport limit of ions and the resistance of electron transport become more and more critical." These effects lead to a rapid decline in capacity retention in the most advanced commercial graphite, silicon, and carbon/silicon anodes and carbon/sulfur cathodes at high quality loads

he added that the problem became worse at high power density. However, because graphene/Nb2O5 nanocomposites can more effectively provide charge and promote charge transmission, even with thick electrodes, the capacity retention rate and current density can still maintain high values under high mass loads

yury gogotsi, director of the Institute of nanomaterials at Drexel University, thinks this work is excellent. The electrode made of new nanocomposites still shows high speed and high regional capacity at the actual useful weight (11 mg/cm2)

he pointed out: "we all hope to charge our and electric vehicles in a few minutes. Porous graphene Nb2O5 composites like this have high electronic and ionic conductivity and can provide high-speed energy storage."

but before new composite materials can be commercialized, the preparation process still needs to be optimized for large-scale production. He said, "continuing to work hard to design new electrode structures can further improve the charge transfer rate and accelerate the development of advanced active materials for batteries."

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