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通过循环伏安(CV)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和傅立叶变换红外(FTIR)光谱研究了双乙二酸硼酸锂(LiBOB)基电解液在石墨表面的成膜性及其在常温(25 ℃)和高温(70 ℃)下对石墨循环性能的影响. 结果表明, LiBOB基电解液的成膜电位在1.7 V, 其中BOB-离子还原形成的草酸盐是固体电解质相界面(SEI)膜的有效成分之一. 电化学阻抗谱显示, 膜阻抗在循环过程中呈现减小趋势, 这有利于提高循环稳定性. 在常温和高温条件下, 石墨在该电解液体系中均表现出优于其在LiPF6基电解液体系中的循环性能. 相似文献
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锂离子电池的发展主要依赖于电极材料的突破,解决现有电极材料存在的问题和预测新型未知材料是提高锂离子电池性能的关键,而第一性原理计算的出现能够较好的满足这一需求。本文介绍了第一性原理计算在锂离子电池正极材料研究方面的原理和应用,并对该原理在正极材料的平均嵌锂电压计算,嵌/脱锂机理、结构稳定性研究及新材料预测等方面的应用进行了详细论述,并指出了这一理论计算工具在电池材料设计过程中的重要性和局限性。 相似文献
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锂离子电池硅-锰复合材料的电化学性能 总被引:3,自引:0,他引:3
The Si-Mn composites were synthesized by ball-milling mixtures of four different atomic ratios of Si/Mn. The phases of composites were analyzed with X-ray diffraction. Their charge-discharge performance as negative electrodes in Li-ion batteries were tested and the formation of SEI film was studied by differential capacity plots. The results show that materials prepared by ball-milling technology are composites consisting of Si and Mn. The insertion of lithium ions leads to the formation of amorphous Li-Si alloy. The initial reversible capacity and efficiency of Si-Mn composites are increased and the cycle life is enhanced obviously,especially after their heat treatment. The composite of Si∶Mn=4∶6 exhibits a reversible capacity of 546.0 mAh·g-1 and a charge-discharge efficiency of 70%. The reversible capacity maintains at 374.2 mAh·g-1 after 40 cycles. 相似文献
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