Unravelling the Interface —25— Layer Formation and Gas Evolution/Suppression on a TiNb2O7 Anode for Lithium-Ion Batteries
Unravelling the Interface —25— Layer Formation and Gas Evolution/Suppression on a TiNb2O7 Anode for Lithium-Ion Batteries
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揭示锂离子电池 TiNb2O7 阳极上 25 层界面的形成和气体逸出/抑制
DOI：
10.1021/acsami.8b08425
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Geping Yin
中科院分区：
文献类型：
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作者：
Xinzhan Wu;Shuaifeng Lou;Xinqun Cheng;Chunhua Lin;Jinlong Gao;Yulin Ma;Pengjian Zuo;Chunyu Du;Yunzhi Gao;Geping Yin
TiNb2O7(TNO)由于在1.0-3.0 V的工作电压范围内具有较高的理论容量和倍率性能，被认为是一种有前途的高功率锂离子电池负极材料。本文通过扫描电子显微镜、高分辨率透射电子显微镜、X射线光电子能谱和 傅里叶变换红外光谱。制备的TNO表现出256 mA h g-1的高初始可逆容量，在0.1 C下循环200次后容量保持率为68.4%。一般认为，在超过1.0 V的高工作电压下可以避免固体电解质界面（SEI）膜的形成。然而，我们发现，薄的SEI层在锂嵌入过程中形成，并在随后的锂提取过程中部分溶解。 过程中，随后 SEI 层在长期循环中逐渐增加。最重要的是，我们首次在TNO/LiFePO4软包电池中发现明显的析气行为，并证明了VC添加剂对全电池膨胀现象的有效抑制作用。
TiNb2O7(TNO) has been regarded as a promising anode material for high-power lithium-ion batteries because of the high theoretical capacity and rate performance within the operation voltage range of 1.0–3.0 V. Herein, the electrochemical performance and interface evolution of TNO are comprehensively investigated by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The prepared TNO shows a high initial reversible capacity of 256 mA h g–1and a satisfactory capacity retention of 68.4% after 200 cycles at 0.1 C. It is generally believed that the formation of solid electrolyte interface (SEI) film could be avoided at the high operating voltage beyond 1.0 V. However, we find that the thin SEI layer is formed during the lithium insertion process and partially dissolved during the following lithium extraction process, and subsequently the SEI layer increases gradually during long-term cycles. Most importantly, we find obvious gassing behavior in the TNO/LiFePO4pouch cell for the first time and demonstrate effective suppression effects of VC additive on the swelling phenomenon of full batteries.