Zhu Yuanchao, Hu Wei, Zhou Jianbin, Cai Wenlong, Lu Yue, Liang Jianwen, Li Xiaona, Zhu Shanshan, Fu Qiqi, Qian Yitai
Department of Chemistry , University of Science and Technology of China, and Hefei National Laboratory for Physical Science at Microscale , Hefei , Anhui Province 230026 , P. R. China.
Shandong Provincial Key Laboratory of Molecular Engineering , Qilu University of Technology , Jinan , Shandong Province 250353 , P. R. China.
ACS Appl Mater Interfaces. 2019 May 22;11(20):18305-18312. doi: 10.1021/acsami.8b22507. Epub 2019 May 13.
SiO coating is an effective strategy to prolong the cycling stability of Si-based anodes due to the robust interaction between Si and the SiO layer. However, the SiO layer-protected Si anode is limited by the relatively low initial Coulombic efficiency and sluggish Li diffusion ability induced by the SiO layer. Herein, we present the preparation of selectively prelithiated Si@SiO (Si@LiSiO) anode by using a facile strategy to resolve the above issues. As the anode for lithium ion batteries, Si@LiSiO exhibits a high initial Coulombic efficiency (ICE) of 89.1%, an excellent rate performance (959 mA h g at 30 A g), and a superior capacity retention (3215 mA h g). The full cell with LiFePO cathode and Si@LiSiO anodes is successfully assembled, disclosing a high ICE of 91.1% and excellent long cycling stability. The superior electrochemical performance of Si@LiSiO can be attributed to the coating layer, which can strengthen the integrity of the electrode, decrease irreversible reactions, and provide efficient Li diffusion channels.
由于硅与二氧化硅层之间存在强相互作用，二氧化硅涂层是延长硅基负极循环稳定性的有效策略。然而，二氧化硅层保护的硅负极受到相对较低的初始库仑效率以及由二氧化硅层引起的缓慢锂扩散能力的限制。在此，我们展示了通过一种简便策略制备选择性预锂化的硅@二氧化硅（硅@锂二氧化硅）负极以解决上述问题。作为锂离子电池的负极，硅@锂二氧化硅表现出89.1%的高初始库仑效率（ICE）、优异的倍率性能（在30 A g下为959 mA h g）以及出色的容量保持率（3215 mA h g）。成功组装了具有磷酸铁锂正极和硅@锂二氧化硅负极的全电池，其初始库仑效率高达91.1%，并具有出色的长循环稳定性。硅@锂二氧化硅优异的电化学性能可归因于涂层，该涂层可增强电极的完整性、减少不可逆反应并提供高效的锂扩散通道。
