Controlled SnO2 Crystallinity Effectively Dominating Sodium Storage Performance

详细信息    查看全文

• 作者：Linlin Fan ; Xifei Li ; Bo Yan ; Jianmin Feng ; Dongbin Xiong ; Dejun Li ; Lin Gu ; Yuren Wen ; Stephen Lawes and Xueliang Sun
• 刊名：Advanced Energy Materials
• 出版年：2016
• 出版时间：May 25, 2016
• 年：2016
• 卷：6
• 期：10
• 全文大小：9379K
• ISSN：1614-6840

文摘

The exploration of sodium ion batteries (SIBs) is a profound challenge due to the rich sodium abundance and limited supply of lithium on earth. Here, amorphous SnO₂/graphene aerogel (a-SnO₂/GA) nanocomposites have been successfully synthesized via a hydrothermal method for use as anode materials in SIBs. The designed annealing process produces crystalline SnO₂/graphene aerogel (c-SnO₂/GA) nanocomposites. For the first time, the significant effects of SnO₂ crystallinity on sodium storage performance are studied in detail. Notably, a-SnO₂/GA is more effective than c-SnO₂/GA in overcoming electrode degradation from large volume changes associated with charge–discharge processes. Surprisingly, the amorphous SnO₂ delivers a high specific capacity of 380.2 mAh g⁻¹ after 100 cycles at a current density of 50 mA g⁻¹, which is almost three times as much as for crystalline SnO₂ (138.6 mAh g⁻¹). The impressive electrochemical performance of amorphous SnO₂ can be attributed to the intrinsic isotropic nature, the enhanced Na⁺ diffusion coefficient, and the strong interaction between amorphous SnO₂ and GA. In addition, amorphous SnO₂ particles with the smaller size better function to relieve the volume expansion/shrinkage. This study provides a significant research direction aiming to increase the electrochemical performance of the anode materials used in SIBs.