摘要
采用化学聚合法合成了PEDOT粉体.将PEDOT/乙炔黑/PTFE和乙炔黑/PTFE分别按质量比4.5/4.5/1和9/1进行混合,调浆后均匀涂覆在镍网上,作为锂氧电池空气电极.用FTIR对复合物的结构进行分析.用四探针法、循环伏安法、恒流充放电法和电化学阻抗法研究了乙炔黑和PEDOT/乙炔黑两种材料的导电性及电化学性能.测试结果表明,乙炔黑/PTFE（9/1）和PEDOT/乙炔黑/PTFE（4.5/4.5/1）的还原电位分别为2.20和2.57 V;乙炔黑/PTFE（9/1）的首次放电比容量为2812 mA h/g,而PEDOT/乙炔黑/PTFE（4.5/4.5/1）的比容量则达到了4056 mA h/g;添加PEDOT使乙炔黑模拟电池的电荷转移阻抗降低了~76.8%,表明PEDOT能够使锂离子在脱/嵌过程中的极化变小.以上结果说明PEDOT能够有效提高乙炔黑的电催化性能.
In this work, poly（3,4-ethylenedioxythiophene） （PEDOT） powders were successfully synthesized by chemical polymerization. PE- DOT/acetylene black/poly（tetrafluoroethylene） （PTFE） and acetylene black/PTFE were mixed in weight ratios of 4.5/4.5/1 and 9/1, respectively. The composites were made into slurries and spread on a nickel foam, which acted as the air electrode in lithium-air batteries. The structures were determined using fourier-transform infrared spectroscopy. The electrical conductivities and electrochemical performances of acetylene black and PEDOT/acetylene black were investigated using the four-probe method, cyclic voltammetry （CV）, the constant current charge/discharge method, and electrochemical impedance spectroscopy （EIS）. The reduction potentials of acety- lene black/PTFE （9/1） and PEDOT/acetylene black/PTFE （4.5/4.5/1） were 2.20 and 2.57 V, respectively. The first discharge capacity of acetylene black/PTFE （9/1） was 2812 mA h/g. However, the first discharge capacity of PEDOT/acetylene black/PTFE （4.5/4.5/1） was 4056 mA h/g, In addition, PEDOT modification reduced the charge transfer resistance by about 7.85%, compared with that of acetylene black. PEDOT lowered the polarization between lithium ion intercalation and de-intercalation. The CV, constant current charge/discharge, and EIS results show that PEDOT can effectively enhance the electrocatalytic properties of acetylene black.
出处
《科学通报》
EI
CAS
CSCD
北大核心
2014年第21期2119-2124,共6页
Chinese Science Bulletin
基金
国家自然科学基金(21206099)资助
关键词
PEDOT
乙炔黑
锂氧电池
阴极
电催化性能
PEDOT, acetylene black, lithium-air batteries, cathode, electrocatalytic properties
