Chen Haihui, Xu Hanying, Zeng Yingying, Ma Tianyi, Wang Wei, Liu Limin, Wang Fang, Zhang Xiangwu, Qiu Xinping
School of Chemistry and Chemical Engineering , Jinggangshan University , Ji'An , Jiangxi 343009 , China.
Wilson College of Textiles , North Carolina State University , Raleigh , North Carolina 27695-8301 , United States.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27839-27845. doi: 10.1021/acsami.9b07400. Epub 2019 Jul 23.
Silicon is considered to be one of the most important high-energy density anode materials for next-generation lithium-ion batteries. A large number of experimental studies on silicon anode have achieved better results, and greatly promoted its practical application potentiality, but almost of them are only tested in metal lithium half batteries. There is still an unavoidable question for commercial applications: what is the performance of the full cell composed of a silicon anode and a manganese-based material cathode? In this paper, the growing solid electrolyte interphase (SEI) and deposited manganese ions of the silicon anode's surface of the spinel lithium manganese oxide LiMnO/silicon full cells are quantitatively studied during electrochemical cycling, and the SEI performances are tested by differential scanning calorimetry to find out the reason for the rapid decline of reversible capacity in the LiMnO/silicon system. The experimental results show that manganese ions can make SEI films rapidly grow on the silicon anode and make SEI films more brittle, which results in lower Coulombic efficiency and rapid decline in capacity of the silicon anode.
硅被认为是下一代锂离子电池最重要的高能量密度负极材料之一。大量关于硅负极的实验研究取得了较好的成果，并极大地推动了其实际应用潜力，但几乎所有这些研究都仅在金属锂半电池中进行测试。对于商业应用来说，仍然存在一个不可避免的问题：由硅负极和锰基材料正极组成的全电池性能如何？本文对尖晶石型锂锰氧化物LiMnO/硅全电池中硅负极表面不断生长的固体电解质界面（SEI）和沉积的锰离子在电化学循环过程中进行了定量研究，并通过差示扫描量热法测试了SEI性能，以找出LiMnO/硅体系中可逆容量快速下降的原因。实验结果表明，锰离子会使SEI膜在硅负极上快速生长，并使SEI膜更脆，从而导致库仑效率降低和硅负极容量快速下降。
