Carbon nanonion-assembled microspheres for excellent gravimetric and volumetric Na-Ion storage
Carbon nanonion-assembled microspheres for excellent gravimetric and volumetric Na-Ion storage
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DOI：
10.1016/j.carbon.2019.07.034
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发表时间：
2019-11
期刊：
影响因子：
10.9
通讯作者：
Beibei Yang;Sitong Liu;Huaihe Song;Jisheng Zhou
中科院分区：
文献类型：
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作者：
Beibei Yang;Sitong Liu;Huaihe Song;Jisheng Zhou
同时具有高重量和体积性能的炭负极材料的设计是钠离子电池（SIB）真实的应用的主要限制之一。在此，我们开发了新型的微米/纳米结构的碳微球（CMS）组装洋葱状碳通过原位热解的方法。当用作SIB的阳极材料时，CMS电极具有1.36 g cm-3的高压制密度。CMS表现出275 mAh g− 1的高可逆重量容量和在100 mA g−1下374 mAh cm− 3的可逆体积容量，这可以与锂离子电池用石墨的体积容量相媲美。在1、2和5 A g−1的高电流密度下，可逆重量容量仍然可以保持在195、165和115 mAh g− 1，体积容量可以达到265、224和156 mAh cm−3。这种优异的电化学性能应归功于CMSs特殊的球形微/纳米结构，它不仅可以保证高密度，而且还提供空隙空间以减轻体积变化并增强Na离子扩散动力学。因此，本研究提出了一种新的策略，同时具有高的重量和体积性能的碳材料的设计。
The 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−1and a reversible volumetric capacity of 374 mAh cm−3at 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−1and 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.