摘要
通过正硅酸乙酯水解、蔗糖热解包覆制备了锂离子电池SiO_(x)@C负极材料。为了减少SiO_(x)@C在首次循环中的不可逆容量损失,采用SiO_(x)@C与金属锂片直接接触的方法对其进行预锂化,考察了不同预锂化处理时间对材料电化学性能的影响,研究了预锂化处理前后材料表面形貌和组成成分的变化,分析了预锂化处理在材料中的作用机理。结果表明,预锂化处理3min后,SiO_(x)@C的首次库伦效率已达到99.2%,高于未预锂化的63.9%,而且仍然表现出较高的循环稳定性。通过SEM、XPS、容量微分曲线、交流阻抗谱等分析,发现预锂化处理过程中SiO_(x)@C已发生不可逆转化反应,并在材料表面形成了SEI膜,从而达到减少首次循环中不可逆容量损失的目的。
SiO_(x)@C anode material for lithium-ion batteries was prepared by hydrolysis of ethyl orthosilicate and pyrolysis of sucrose.In order to reduce irreversible capacity loss of the SiO_(x)@C in the first cycle,we used the method of direct contact between the SiO_(x)@C@C and the metal lithium sheet to achieve the purpose of prelithiation.The influence of different prelithiation treatment time on the electrochemical performance of SiO_(x)@C@C was investigated.The changes of the surface morphology and composition of SiO_(x)@C@C before and after prelithiation were studied.The mechanism of prelithiation in SiO_(x)@C was analyzed.The results indicated that the initial Coulombic efficiency of the SiO_(x)@C with a prelithiation treatment of 3min reached 99.2%,which was much higher than the 63.9%of the SiO_(x)@C without prelithiation.The prelithiated SiO_(x)@C also exhibited high cycle stability.SEM,XPS,dQ/dV curves,EIS analyses showed that the SiO_(x)@C had undergone an irreversible conversion reaction and formed SEI film on its surface during prelithiation process,thereby achieving the purpose of reducing the irreversible capacity loss in the first cycle.
作者
张正裕
白哲
何洁龙
吴佳霓
蓝利芳
李军
Zhang Zhengyu;Bai Zhe;He Jielong;Wu Jiani;Lan Lifang;Li Jun(School of Light Industry and Chemical Engineering,Guangdong University of Technology,Guangzhou 510006)
出处
《化工新型材料》
CAS
CSCD
北大核心
2023年第4期170-174,共5页
New Chemical Materials
基金
佛山市科技计划项目(1920001001421)。
