On-demand design of polyoxianionic cathode materials based on electronegativity correlations:: An exploration of the Li2MSiO4 system (M = Fe, Mn, Co, Ni)
On-demand design of polyoxianionic cathode materials based on electronegativity correlations:: An exploration of the Li2MSiO4 system (M = Fe, Mn, Co, Ni)
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DOI：
10.1016/j.elecom.2006.06.003
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发表时间：
2006-08-01
影响因子：
5.4
通讯作者：
Amador, U.
中科院分区：
文献类型：
--
作者：
Arroyo-de Dompablo, M. E.;Armand, M.;Amador, U.
采用第一性原理研究了不同多氧离子（XO4）（n-） （X = Ge, Si, Sb, As， P）对橄榄石- lico +2XO4， LiyV+4OXO4和LiyM+2XO4 （Li2FeSiO4结构内的M Mn， Fe, Co, Ni）化合物的锂脱嵌电压的影响。在所有情况下，计算出的锂脱嵌电压与Mulliken X电负性相关，对每种结构类型/氧化还原偶都显示出线性依赖关系。文献中已有的实验锂脱嵌电压支持这些结果。利用Li2MSiO4的计算结果来评价这些材料的电化学性能。Li2FeSiO4将发展一种可逆比容量，限制在提取一个锂离子。预测Li2MnSiO4具有较差的电子导电性。计算得到的Co和Ni硅酸盐的锂萃取电压对于目前的电解质来说过高。优化后的MSiO4结构表明该基质是不稳定的，并指出锂电池在充放电过程中可能发生结构转变。(c) 2006 Elsevier B.V.版权所有
A first principles investigation is performed to quantify how the inductive effect of different polyoxianions (XO4)(n-) (X = Ge, Si, Sb, As, P) affects the lithium deintercalation voltage of olivine-LiCo+2XO4, LiyV+4OXO4 and LiyM+2XO4 (M Mn, Fe, Co, Ni within the structure of Li2FeSiO4) compounds. In all cases, the calculated lithium deintercalation voltage correlates to the Mulliken X electronegativity, displaying a linear dependence for each structural type/redox couple. Experimental lithium deinsertion voltages already available in the literature support these results. Computational results on Li2MSiO4 are used to evaluate the electrochemical performance of these materials. Li2FeSiO4 will develop a reversible specific capacity limited to the extraction of one lithium ion. Li2MnSiO4 is predicted to have a poor electronic conductivity. The calculated lithium extraction voltages of Co and Ni silicates are too high for current electrolytes. The optimized structure of the fully delithiated MSiO4 suggests that this host is unstable, pointing out to a possible structural transformation during the charge/discharge of the lithium cells. (c) 2006 Elsevier B.V. All rights reserved.