Preparation of High Lithium Ion Conducting Glass-Ceramics by Mechanical Milling

1.在室温干燥N2气氛下，用机械球磨法制备了Li_2S-P_2S_5，Li_2S-P_2S_5-SiS_2，Li_2S-P_2S_5-GeS_2三个系统的非晶材料。这些玻璃态材料的颗粒状样品在25℃下表现出约10 μ Scm ~ 2的高电导率<-4><-1>。结果表明，玻璃态材料的锂离子输运数几乎为1，作为固体电解质的电位窗口大于10 V.通过对MM法制备的上述玻璃材料进行不同条件的热处理，得到了高导电微晶玻璃。在230℃左右热处理后得到的微晶玻璃的X射线衍射图谱与Li_ Ge_ P_xS_4中的高导电硫代LISICON II相非常相似<4-x><1-x>，这表明在这些体系中，硫代-LISICON II类似物形成于由机械研磨的玻璃态粉末衍生的玻璃陶瓷中。通过对元素原料的MM，也得到了高导电微晶玻璃。通过对Li 2S、P、S的MM反应，成功地制备了Li 2S-P2 S5玻璃态样品。玻璃态样品的性质和结构与用Li_2S和P_2S_5制备的样品非常相似。这种元素衍生硫化物玻璃经热处理后得到的微晶玻璃具有与P_2S_5衍生玻璃相似的性能.采用MM法和热处理法制备的Li_2S-P_2S_5系统微晶玻璃为电解质，LiCoO_2为正极，铟为负极，制备了电化学电池。全固态电池表现出优异的循环性能，即使在200次循环后可逆充放电容量也为约100 mAhg<-1>/g。

1. Amorphous materials with various compositions in the systems Li_2S-P_2S_5, Li_2S-P_2S_5-SiS_2, and Li_2S-P_2S_5-GeS_2 were prepared by mechanical milling (MM) of crystalline starting materials in a dry N_2 atmosphere at room temperature. The pelletized samples of these glassy materials exhibited high conductivities in the order of 10^<-4> Scm^<-1> at 25℃. It was found that the transport number of lithium ions of the glassy materials was almost unity and the potential window as solid electrolytes was wider than 10 V.2. Highly conductive glass-ceramics were obtained by the heat treatment under a variety of conditions of the above glassy materials prepared by MM. The glass-ceramics obtained after heating at around 230℃ showed the X-ray diffraction patterns very similar to those of highly conductive thio-LISICON II phases in Li_<4-x>Ge_<1-x>P_xS_4, suggesting that the thio-LISICON II analogue is formed in the glass-ceramics derived from the mechanically milled glassy powder in these systems.3. The highly conductive glass-ceramics were also obtained by the MM of starting materials of elements. Glassy Li_2S-P_2S_5 samples were successfully prepared by the MM of Li_2S, P, and S. The properties and structure of the glassy samples are very similar those of the samples prepared using Li_2S and P_2S_5. The glass-ceramics obtained by the heating of such an element-derived sulfide glasses exhibited similar properties to the glass-ceramics from P_2S_5-derived glasses.4. Electrochemical cells were constructed using glass-ceramics in the system Li_2S-P_2S_5 obtained by MM and heat treatment as an electrolyte, LiCoO_2, as a positive electrode and indium as a negative electrode. The all-solid-state cell exhibited excellent cycling performances with the reversible charge-discharge capacities of about 100mAhg^<-1> even after 200 cycles.