[Figure 1] conversion reaction of oxide during cycle life
Professor Wonsub YOON’s research team (Dept. of Energy Science)’s thesis on the discovery of dynamic cycle life has been published on the May 28th issue of “ACS Nano”, which is a prestigious journal in the area of materials science.
MxOy based on conversion reaction are receiving highlight in the academic world to be used as a material for next-generation batteries. However, there is a clear limitation since it accompanies agglomeration and the best they can produce is the MxOy- δ.
The research team tried to overcome this limit by designing the element in a single phase structure. They have also designed it to recover oxidation number so that it improves the contact opportunity of metal and oxygen during the process of expansion and contraction. They have induced complete conversion reaction by creating acompound out of graphene oxide and tin ferrite structure of Fe3O4 lattice. It has reached the maximum performance ever reported from Sn based compound oxide,which is ~1400 mAh/g. This is far greater than the conventional graphite cathodic material (~370 mAh/g).
This research also explained the phase transformation of host structure during the battery cycle life of iron oxide to iron oxyhydroxide. The team has suggested a new frame in understanding conversion reaction. This research was conducted through the basic research support project of the National Research Foundation of Korea.
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