α-和β-Li_2MnP_2O_7嵌锂电压和弹性性质的第一原理计算
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- 英文论文题名：First principle study on the electrochemistry and elastic property of α- and β-Li_2MnP_2O_7
- 论文作者：侯晓颖 ; 梁晶 ; 唐树伟 ; 王荣顺
- 英文论文作者：Xiaoying Hou ; Jing Liang ; Shuwei Tang ; Rongshun Wang ; Faculty of Chemistry ; Northeast Normal University
- 年：2016
- 作者机构：东北师范大学化学学院;
- 论文关键词：焦磷酸锰锂 ; 第一原理方法 ; 嵌锂电压 ; 弹性常数
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十九分会：电化学材料
- 语种：中文
- 分类号：O611.3
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十九分会 ; 电化学材料
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：345k
- 原文格式：D
- 会议级别：全国
摘要
焦磷酸盐化合物在锂离子电池材料领域显示出巨大的潜力和优势,已经引起了人们的广泛关注。本文基于密度泛函理论,采用第一性原理投影缀加平面波赝势方法对焦磷酸盐的α-Li_2MnP_2O_7和β-Li_2MnP_2O_7两种体相材料的电子和几何结构,弹性性质等进行计算和分析。通过研究这两种体相材料的嵌锂态和脱锂态结构,探究其嵌锂电压等电化学性质。计算结果表明,随着锂原子的脱去,材料的DOS能隙变小,导电性质增强。Bader电荷分析表明电荷转移主要发生在锰原子和氧离子上,说明了在充放电过程中,比较活跃的是Mn2+/Mn3+氧化还原电对。在弹性性质的计算中发现脱锂后β-Li_2MnP_2O_7的B/G的值大于1.75,但是泊松比却小于0.3这个临界值。
First principle calculations have been performed to evaluate the effect of delithiation on the electrochemical performance and elastic property of α- and β-Li_2MnP_2O_7. On the basis of optimized structures, the density of states(DOS), bader charge and elastic constants are studied for these two bulk materials. The computational results show that the energy gap became smaller with the deinsertion of Li ion from the original host structure both in the α- and β-phase. To gain further insight into the electron contributions from different atoms, the Bader effective charge on atoms in lithiated and delithiated states are investigated, which shows that the effective charges of P, O, and Li are almost unchanged. However, the effective charge of Mn is 1.56e/1.87 e in β phase during the charge/discharge process, which confirms that the active role of Mn~(2+)/Mn~(3+) in the delithiation. In addition, the elastic property for delithiated structures are also changed.
First principle calculations have been performed to evaluate the effect of delithiation on the electrochemical performance and elastic property of α- and β-Li_2MnP_2O_7. On the basis of optimized structures, the density of states(DOS), bader charge and elastic constants are studied for these two bulk materials. The computational results show that the energy gap became smaller with the deinsertion of Li ion from the original host structure both in the α- and β-phase. To gain further insight into the electron contributions from different atoms, the Bader effective charge on atoms in lithiated and delithiated states are investigated, which shows that the effective charges of P, O, and Li are almost unchanged. However, the effective charge of Mn is 1.56e/1.87 e in β phase during the charge/discharge process, which confirms that the active role of Mn~(2+)/Mn~(3+) in the delithiation. In addition, the elastic property for delithiated structures are also changed.
引文
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[2]Nishimura,S.;Natsui,R.;Yamada,A.Dalton T.,2014,43:1502.
[3]Zhu,L.;Li,L.;Cheng,T.;Xu,D.J.Mater.Chem.A,2015,3:5449.
[4]Cai,Y.;Chen,G.;Xu,X.;Du,F.;Li,Z.;Meng,X.;Wang,C.;Wei,Y.J.Phys.Chem.C,2011,115:7032.
[5]Zhu,L.;Li,L.;Cheng,T.-M.Comput.Mater.Sci.,2015,106:135.
[6]Zhu,L.;Li,L.;Cheng,T.;Xu,D.J.Mater.Chem.A,2015,3:5449.