NMR and Phonon-Echo Study on the Ionic Operation of Electrode Materials of Lithium Ion Batteries

研究结果总结如下：1. 实验(1)样品制备：以Li_2O、LiOH和CuO粉末为原料合成正极材料LiCu0_2。LiV_2O_5粉末由印度Bharathiar大学提供，LiGa由法政大学和青森大学集团提供，碳粉由松下电池工业株式会社提供。(2)测量：测量了LiCoO_2、LiNiO_2、LiCuO_2和LiV_2O_5中^7Li的自旋晶格弛豫时间T_1和线宽ΔH与温度的关系。用核磁共振谱测定了LiCuO_2和LiV_2O_5的化学位移。用四端法测定了LiCoO_2和LiNiO_2的电导率随温度的变化规律。在77K ~ 500k的温度范围内，对β -LiGa中的^7Li和^<71>Ga进行了核磁共振测量。(1)根据两种样品的核磁共振和电导率数据，讨论了用LiNiO_2代替LiCoO_2的可行性。进行了四次口头报告，发表了一篇论文。(2)从核磁共振谱线宽的角度讨论了LiCuO_2作为正极的实际应用可能性，给出了一篇口头报告和一篇论文。(3)通过核磁共振测量研究了β -LiGa中Li^+缺陷的行为，并讨论了作为负极的效率。除三篇论文外，还作了六次口头报告。(4)碳粉无法观测到声子回波。目前正在进行进一步调查。

Research results are summarized as follows. 1. Experiments(1) Sample preparation : Positive electrode material, LiCu0_2 was synthesized from Li_2O, LiOH and CuO powders. The powder of LiV_2O_5 was supplied by Bharathiar Univ. (India), LiGa by Hosei Univ. and Aomori Univ. Group, and Carbon powder by Matsushita Battery Industrial Co.,Ltd.(2) Measurements : The temperature dependence of the spin-lattice relaxation time T_1 and the line width ΔH have been measured for ^7Li in LiCoO_2, LiNiO_2, LiCuO_2 and LiV_2O_5. The chemical shift has been measured in LiCuO_2 and LiV_2O_5 by MAS-NMR. The electrical conductivity has been measured in LiCoO_2 and LiNiO_2 as a function of temperature by a four-terminal method. NMR measurement has been done for ^7Li and ^<71>Ga in β -LiGa over the temperature range of 77K〜500K.2. Results and Summary(1) We discussed about using LiNiO_2 instead of LiCoO_2 from NMR and conductivity data of both samples. Four oral presentations were given and one paper was published.(2) From the discussion about the possibility of the practical use of LiCuO_2 as the positive electrode from NMR Line width, we gave one oral report and one paper.(3) We investigated the behavior of Li^+ defects in β -LiGa by NMR measurements and discussed about the efficiency as the negative electrode. Six oral presentations were given in addition to three papers.(4) We could not observe the phonon echoes for the carbon powder. Further investigations are now being performed.