层状材料LiNi_xCo_(1-2x)Mn_xO_2的表面偏析与体相电导率
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- 英文论文题名：Surface segregation and bulk conductivity of LiNi_xCo_(1-2x)Mn_xO_2 as cathode material for Li-ion batteries
- 论文作者：李国华 ; 李莉萍 ; 范建明 ; 李广社
- 英文论文作者：Guohua Li ; Liping Li ; Jianming Fan ; Guangshe Li ; Fujian institute of research in structure of matter ; Chinese Academy of Sciences ; State key laboratory of inorganic synthesis and preparative chemistry ; Institute of Chemistry ; Jilin University
- 年：2016
- 作者机构：中国科学院福建物质结构研究所;无机合成与制备化学国家重点实验室化学学院吉林大学;
- 论文关键词：表面偏析 ; 体相电导率 ; 层状氧化物
- 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：327k
- 原文格式：D
- 会议级别：全国
摘要
层状氧化物LiNi_xCo_(1-2x)Mn_xO_2具有容量高,热稳定性好等优点,被认为是下一代先进能源材料的候选者。但仍存在一些共性的基础问题还末完全清楚,如表面偏析,及电导率。在实际使用中,这些属性对材料的电化学性能有着重大的影响。因此急切需要揭示本体材料的真相。我们分别采用软XPS深度剖析方法和交流阻抗法研究了这类层状氧化物的表面偏析现象、规律及其电学行为。结果表明这类氧化物具有表面偏析行为:组分Ni和Mn趋于在样品的表面富集;而对于组分Co则具有反偏析的行为;并且它们的相对偏析量是随组分Ni的含量增加而减少的,表现出了组分协同效应。对其体相电导率的研究得到:体相的活化能与锂层厚度有着密切的联系,体相活化能随锂层厚度减少而增加。这项研究可以为我们选择材料和设计材料提供思路。
The family of LiNi_xCo_(1-2x)Mn_xO_2 is considered as a candidate for next general advance energy materials with high capacity and excellent thermal ability. However, some mutual science problems of these compounds are not real clearly, such as surface segregation and conductivity. In practical application, these attributions have a remark effect on the electrochemical performance. Hence, it is very urge to reveal the true of pristine material. The soft XPS depth profiling and AC impedance spectrum were carried out to investigate surface segregation behavior and bulk conductivity. The results show that the composition Ni and Mn tend to enrich at the surface region; For Co, it have a anti-segregation behavior. Relative segregation is decrease with the content of Ni increase and the behaviors exhibit composition synergy effect. The activity energy of bulk is close relation with the LiO_2 slab and increase with the slab deduce. The study can provide some minds for us to choose materials and design new materials.
The family of LiNi_xCo_(1-2x)Mn_xO_2 is considered as a candidate for next general advance energy materials with high capacity and excellent thermal ability. However, some mutual science problems of these compounds are not real clearly, such as surface segregation and conductivity. In practical application, these attributions have a remark effect on the electrochemical performance. Hence, it is very urge to reveal the true of pristine material. The soft XPS depth profiling and AC impedance spectrum were carried out to investigate surface segregation behavior and bulk conductivity. The results show that the composition Ni and Mn tend to enrich at the surface region; For Co, it have a anti-segregation behavior. Relative segregation is decrease with the content of Ni increase and the behaviors exhibit composition synergy effect. The activity energy of bulk is close relation with the LiO_2 slab and increase with the slab deduce. The study can provide some minds for us to choose materials and design new materials.
引文
[1]Fu,C.C.;Li,G.S.;Luo,D.;Li,Q.;Fan,J.M.;Zheng,J.;Li,L.P..ACS Applied Materials&Interfaces 2014,6(18),15822-15831.