Investigation of lithium insertion in anode material NiSi2 for lithium-ion batteries

• 作 者: Jing Ding Zhaohui Long Xibo Li Fucheng Yin
• 机 构: School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan, 411105, China
• 出 处: 第十七届全国相图学术会议暨相图与材料设计国际研讨会
• 发表日期: 2015年12期
• 关键词: Lithium-ion batteries Anode material Ni-Si alloy First-principles

　　The mechanism of Li insertion into anode material NiSi2 for lithium-ion batteries is investigated by first-principle based on the density functional theory.The results reveal that the most possible reaction pathway during the process of Li insertion into NiSi2 is: 12/7Li++12/7e NiSi2+ 1/7Li12Si7 NiSi,13/8Li++13/8e NiSi+ 1/8Li13Si4 1/2δ-Ni2Si , δ-Ni2Si Ni2Si(anti-fluoritestructure) , Li++e Ni2Si+ LiNi2Si.Ni atoms can greatly buffer the volume effect, which benefits cycling performance.Li atoms can easily insert into and extract out of the anti-fluorite structured Ni2Si (Ni8Si4) due to the medium Li intercalation formation energy that the average value is around 0.76eV.The result of energy band structure shows that the LixNi8Si4 phases present good metallic character.