CeO_2纳米晶的添加对锂硫电池电化学性能的影响  

Effects of CeO_2 Nano-crystal on Electrochemical Properties of Lithium/Sulfur Batteries

作　　者：马国强[1] 温兆银[1] 王清松[1] 靳俊[1] 吴相伟[1] 张敬超[1] 

机构地区：[1]中国科学院上海硅酸盐研究所中国科学院能量转换材料重点实验室,上海200050

出　　处：《无机材料学报》2015年第9期913-918,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金重点项目(51372262;51472261;51402330)~~

摘　　要：以Ce(OH)4为原料,采用热分解法制备得到粒径小于10 nm的CeO2纳米晶。制备得到的CeO2纳米晶表面存在丰富的羟基和硝基,作为硫正极添加剂,一方面可以有效吸附硫和多硫化锂,抑制多硫化锂在电解液中的溶解和穿梭效应的发生,进而提高电池的循环性能。同时,可以改善电极和电解液之间的接触性,提高活性物质利用率。其中,含有5wt%的CeO2纳米晶的锂硫电池在0.1C和0.5C(1C=1675 m A/g)的充放电倍率下,100周之后放电比容量分别达750 m Ah/g和598 m Ah/g,远高于不含有CeO2纳米晶的523 m Ah/g和395 m Ah/g,同时,循环前后的电池阻抗也明显降低。The CeO2 nano-crystal less than 10 nm was fabricated by using thermal decomposition method with Ce（OH）4 as the raw material. CeO2 nano-crystal with abundant –OH and –NO2 was used as the additive in the sulfur cathode. The additive can adsorb sulfur and lithium polysulfides during charge/discharge process, suppressing the dissloving and migrating of lithium polysulfides in the electrolyte. Thus the ＂shuttle effect＂ caused by dissloving of lithium polysulfides can be evidently inhibited, resulting in the enhanced cycle performance and the improved coulombic efficiency of Li-S battery. Furthermore, CeO2 nano-crystal with abundant –OH and –NO2 is beneficial to enhance the wettability between electrolyte and sulfur cathode, improving the utilization rate of active material. With 5wt% CeO2 nano-crystal added in the sulfur cathode, the discharge capacities at 0.1C and 0.5C（1C=1675 m A/g） after 100 cycles are as high as 750 m Ah/g and 598 m Ah/g, respectively, both much higher than those of the sulfur cathode without CeO2 nanocrystal. Simultaneously, the resistance of the cell is also reduced evidently before and after cycling owing to the addition of CeO2 nano-crystal in the cathode.

关 键 词：锂硫电池 CeO2纳米晶 电极添加剂 循环性能 

分 类 号：TQ174[化学工程—陶瓷工业]