When it comes to the word frying and roasting, the feeling of tasty food comes to mind to mouth watering food that results at the end of these processes.
But a research group led by Sang-Hoon Park, a materials scientist at Yonsei University, have just published their research regarding deep frying graphene oxide, into graphene microspheres.
In past few other groups succeeded only with less bulky graphene nanospheres and microspheres using 3-D templates and techniques such as chemical vapor deposition and freeze-drying.
These Graphene microspheres synthesized by Park et al however contain graphene nanosheets radiating out from the center. The arrangement increases the exposed surface area of the graphene and creates open nanochannels that can enhance charge transfer.
Aqueous graphene oxide suspension was sprayed into a high-temperature (160 °C ) nonpolar organic solvent (1-octanol) that contains a reducing agent (l-ascorbic acid). The resulting graphene microspheres have been shown to improve electrochemical performance in terms of specific capacitance and rate capability; due to their structural and pore characteristics.
These microspheres can deliver the much needed improvement in the cycling performance of Li-ion batteries. The synthesis method modified by including Si can result in hybrid Si/G microspheres structures, suitable for use in Li-ion batteries, by providing more suitable framework to buffer the considerable volume change that occurs in Si during electrochemical lithiation/delithiation.
Consequently, a Si/graphene microsphere-based electrode exhibits significantly improved cycling performance and a higher rate capability than that of a simple Si/graphene mixture-based electrode.
The group also suggests viability of process being direct, simple, and much easier to scale up towards industrial mass production.
Image taken from their work published in http://pubs.acs.org/doi/full/10.1021/cm5034244
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