Carbon nanonion-assembled microspheres for excellent gravimetric and volumetric Na-Ion storage

Publication date: November 2019Source: Carbon, Volume 153Author(s): Beibei Yang, Sitong Liu, Huaihe Song, Jisheng ZhouAbstractThe design of carbon anode materials with both high gravimetric and volumetric performances is one of the main limitations in the real applications of sodium-ion batteries (SIBs). Herein, we develop novel micro/nanostructure carbon microspheres (CMSs) assembled of onion-like carbons via an in situ pyrolysis approach. When used as anode materials for SIBs, the CMSs electrode possesses a high pressing density of 1.36 g cm−3. The CMSs exhibit a high reversible gravimetric capacity of 275 mAh g−1 and a reversible volumetric capacity of 374 mAh cm−3 at 100 mA g−1, which can be comparable to the volumetric capacity of graphite for lithium-ion batteries. At high current densities of 1, 2 and 5 A g−1, the reversible gravimetric capacities can still be maintained at 195, 165 and 115 mAh g−1 and the volumetric capacities can reach up to 265, 224 and 156 mAh cm−3. Such excellent electrochemical performances should be attributed to the special spherical micro/nanostructure of CMSs, which can not only guarantee a high density, but also provide void spaces to alleviate the volume variation and enhance Na ions diffusion kinetics. Accordingly, this study proposes a new strategy for the design of carbon materials with both high gravimetric and volumetric performances.Graphical abstractCarbon nanonion-assembled microspheres (CMSs) with unique m...
Source: Carbon - Category: Materials Science Source Type: research