粉末非晶硅制备及其气体氢化和电化学储氢性能研究  

Preparation of amorphous silicon powder and its hydrogenation and electrochemical hydrogen storage properties

作　　者：杨倩 罗永春[1,2] 张海民 尤超 杨淞婷 YANG Qian;LUO Yong-chun;ZHANG Hai-min;YOU Chao;YANG Song-ting(Department of Materials Science and Engineer,Lanzhou University of Technology,Lanzhou 730050,G ansu,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou 730050,Gansu,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学有色金属先进加工与再利用省部共建国家重点实验室,甘肃兰州730050

出　　处：《金属功能材料》2020年第2期44-52,共9页Metallic Functional Materials

摘　　要：以Li13Si4为原料采用化学去锂化法制备了具有层状结构的非晶硅(α-Si)粉体并对α-Si进行球磨改性,研究了改性前后α-Si在H2中的氢化行为以及氢化处理对α-Si电极在质子传导离子液体中的电化学储氢性能影响。研究结果表明,球磨能明显减小α-Si粉体的颗粒尺寸,但易引入Fe和Cr金属杂质并形成Fe2Si与CrSi2。氢化时α-Si逐渐发生晶化,当氢化时间不少于8 h时,α-Si基本完全晶化,氢化后的SiHx结构由SiH、SiH2和SiH3三种成键模式组成。球磨改性有助于增加α-Si的初始吸氢量,随氢化时间延长,α-Si的吸氢量逐渐增大,其中经球磨和氢化2、5、8和58 h后的α-Si吸氢量分别达到(质量分数)0.38%、0.76%、0.91%和3.8%,其吸氢速率比较缓慢。α-Si电极在质子型离子液体中具有电化学吸放氢反应活性,但其放电容量偏低(42~163 mAh/g),其中球磨和氢化8 h的α-Si经20次充放电后具有最大放电容量163 mAh/g。球磨改性和适当的氢化处理(8 h)有利于提高α-Si电极的放电容量。Amorphous silicon(α-Si) powder with layered structure was prepared by chemical delithiation from Li13Si4 compounds and the ball milling modification of α-Si was carried out subsequently. The hydrogenation behavior of the α-Si before and after modification in H2 and the effect of hydrogenation treatment on the electrochemical hydrogen storage performance of the α-Si electrode in proton conducting ionic liquid were investigated. The results showed that ball milling could obviously reduce the particle size of α-Si, but it introduced Fe, Cr impurities and formed Fe2Si and CrSi2. Crystallization of α-Si occurred gradually during hydrogenation and α-Si were completely crystallized when the hydrogenation time was more than 8 h. The structure of SiHx were composed of SiH, SiH2 and SiH3. Ball milling contributed to increase the initial hydrogen absorption of α-Si and the hydrogen absorption increased gradually with the hydrogenation time prolonged, while the hydrogen absorption of α-Si for 2, 5, 8 and 58 h were 0.38 wt%, 0.76 wt%, 0.91 wt% and 3.8 wt%, respectively, but the rate of hydrogen absorption in later stage were relatively slow. There were electrochemical hydrogen absorption and desorption activity for α-Si electrode in proton conducting ionic liquid, but its discharge capacity were relatively low(42-163 mAh/g), which the α-Si with ball milling and hydrogenation for 8 h had the maximum discharge capacity 163 mAh/g after 20 cycles. Ball milling modification and proper hydrogenating treatment(8 h) were favorable to improve the discharge capacity of α-Si electrode.

关 键 词：粉体非晶硅 气体氢化行为 质子型离子液体电解质 电化学储氢性能 

分 类 号：TQ127.2[化学工程—无机化工] O646.5[理学—物理化学]