Codoped Holey Graphene Aerogel by Selective Etching for High‐Performance Sodium‐Ion Storage,Advanced Energy Materials

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Codoped Holey Graphene Aerogel by Selective Etching for High‐Performance Sodium‐Ion Storage
Advanced Energy Materials ( IF 24.4 ) Pub Date : 2020-03-20 , DOI: 10.1002/aenm.202000099
Jin Zhao ₁ , Yi‐Zhou Zhang ₂ , Jianyu Chen ₁ , Wenli Zhang ₂ , Du Yuan ₃ , Rodney Chua ₃ , Husam N. Alshareef ₂ , Yanwen Ma ₁

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The pursuit of more efficient carbon‐based anodes for sodium‐ion batteries (SIBs) prepared from facile and economical methods is a very important endeavor. Based on the crystallinity difference within carbon materials, herein, a low‐temperature selective burning method is developed for preparing oxygen and nitrogen codoped holey graphene aerogel as additive‐free anode for SIBs. By selective burning of a mixture of graphene and low‐crystallinity carbon at 450 °C in air, an elastic porous graphene monolith with abundant holes on graphene sheets and optimized crystallinity is obtained. These structural characteristics lead to an additive‐free electrode with fast charge (ions and electrons) transfer and more abundant Na⁺ storage active sites. Moreover, the heteroatom oxygen/nitrogen doping favors large interlayer distance for rapid Na⁺ insertion/extraction and provides more active sites for high capacitive contribution. The optimized sample exhibits superior sodium‐ion storage capability, i.e., high specific capacity (446 mAh g⁻¹ at 0.1 A g⁻¹), ultrahigh rate capability (189 mAh g⁻¹ at 10 A g⁻¹), and long cycle life (81.0% capacity retention after 2000 cycles at 5 A g⁻¹). This facile and economic strategy might be extended to fabricating other superior carbon‐based energy storage materials.

中文翻译：

共蚀刻有孔石墨烯气凝胶的选择性蚀刻，用于高性能钠离子存储

寻求通过简便而经济的方法制备的钠离子电池（SIB）的更高效碳基负极是一项非常重要的工作。根据碳材料内部的结晶度差异，本文开发了一种低温选择性燃烧方法，用于制备氧和氮共掺杂的多孔石墨烯气凝胶，作为SIB的无添加剂阳极。通过在空气中于450°C下选择性燃烧石墨烯和低结晶度碳的混合物，可以获得在石墨烯片上具有大量孔的弹性多孔石墨烯整料，并具有最佳的结晶度。这些结构特征导致无添加剂电极具有快速的电荷（离子和电子）转移和更丰富的Na ⁺存储活动站点。此外，杂原子氧/氮掺杂有利于较大的层间距离，以实现快速的Na ⁺插入/萃取，并为高电容贡献提供更多的活性位点。优化的样品显示出优异的钠离子存储容量，即，高的比容量（446毫安克^-1 0.1 A G ^-1），超高倍率性能（189毫安克^-1以10 A G ^-1），和长周期寿命（在5 A g ^-1下进行2000次循环后，容量保持率为81.0％）。这种简便而经济的策略可能会扩展到制造其他优质的碳基储能材料。

更新日期：2020-03-20

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