原位环境透射电镜研究SnO2纳米线作为K-O2电池空气正极的放电行为  

In situ imaging of the oxygen reduction reactions of solid state K-O2 batteries with SnO2 nanowires as the air cathode

作　　者：张利强 唐永福[2] 刘秋男 杨婷婷 孙海明 贾鹏 黄建宇 ZHANG Li-qiang;TANG Yong-fu;LIU Qiu-nan;YANG Ting-ting;SUN Hai-ming;JIA Peng;HUANG Jian-yu(Clean Nano Energy Center,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao Hebei 066004;Hebei Key Laboratory of Applied Chemistry,College of Environmental and Chemical Engineering,Yanshan University,Qinhuangdao Hebei 066004;School of Materials Science and Engineering,Xiangtan University,Xiangtang Hunan 411105,China)

机构地区：[1]清洁纳米能源中心,燕山大学材料科学与工程学院,河北秦皇岛066004 [2]燕山大学环境与化学工程学院,河北秦皇岛066004 [3]湘潭大学材料科学与工程学院,湖南湘潭411105

出　　处：《电子显微学报》2020年第6期621-627,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(Nos.52022088,51971245,51772262,U20A20336).

摘　　要：本文使用先进的球差校正环境透射电子显微镜(AC-ETEM)与原位电化学测试平台,在环境透射电镜中以SnO2纳米线作为空气正极,构建起一纳米K-O2金属空气电池,原位观测该电池在氧还原反应(ORR)过程中的微观变化行为。实验结果表明:在ORR过程中,SnO2纳米线首先转化为Sn单质颗粒与K2O;因纳米尺度的Sn单质颗粒具有优异的催化活性,在O2氛围中纳米线的表面生成了大量的KO2。但由于KO2不能稳定存在,会迅速分解成K2O2并释放O2,导致材料发生巨大的体积膨胀。相关实验结果为宏观K-O2电池的设计与改性提供了直观的实验证据。We reported the real time imaging of the oxygen reduction reactions(ORRs)in all solid state potassium oxygen(K-O2)batteries with SnO2 nanowires(NWs)as the air cathode in an aberration-corrected environmental transmission electron microscope under an oxygen environment.It is found that SnO2 NWs were first converted to K2O and metallic Sn nanoparticles(NPs)in the ORR.It is evident that the freshly formed Sn NPs in the conversion reaction catalyzed the latter ORR,leading to the formation of KO2,which was unstable and quickly disproportionated into K2O2 and O2.Consequently,a large volume expansion was generated in the NW.These results provide fundamental understanding into the oxygen chemistry in the carbonless air cathode in all solid state K-O2 batteries.

关 键 词：原位环境透射电子显微镜 SnO2纳米线 K-O2电池 氧还原反应 

分 类 号：TB383[一般工业技术—材料科学与工程] TG115.215.2[金属学及工艺—物理冶金]