TY - JOUR
T1 - Greatly promoted oxygen reduction reaction activity of solid catalysts by regulating the stability of superoxide in metal-O2 batteries
AU - Wang, Hua
AU - Liu, Liangliang
AU - Liu, Xiao
AU - Jia, Yu
AU - Zhang, Peng
AU - Zhang, Yong
N1 - Publisher Copyright:
© 2020, Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/4
Y1 - 2021/4
N2 - Oxygen reduction reactions (ORRs) with one- or two-electron-transfer pathways are the essential process for aprotic metal-oxygen batteries, in which the stability of superoxide intermediates/products (O2−, LiO2, NaO2, etc.) mainly dominates the ORR activity/stability and battery performance. However, little success in regulating the stability of the superoxides has been achieved due to their highly reactive characteristics. Herein, we identified and modulated the stability of superoxides by introducing anthraquinone derivatives as cocatalysts which functioned as superoxide trapper adsorbing the superoxides generated via surface-mediated ORR and then transferring them from the solid catalyst surface into electrolyte. Among the studied trappers, 1,4-difluoroanthraquinone (DFAQ) with electron-withdrawing groups showed the highest adsorption towards superoxides and could efficiently stabilize LiO2 in electrolyte, which greatly promoted the surface-mediated ORR rate and stability. This highlighted the magnitude of adsorption between the trapper and LiO2 on the ORR activity/stability. Using an aprotic Li-O2 battery as a model metal-O2 battery, the overall performance of the cell with DFAQ was substantially improved in terms of cell capacity, rate capability and cyclic stability. These results represent a significant advance in the understanding of ORR mechanisms and promoting the performance of metal-O2 batteries.
AB - Oxygen reduction reactions (ORRs) with one- or two-electron-transfer pathways are the essential process for aprotic metal-oxygen batteries, in which the stability of superoxide intermediates/products (O2−, LiO2, NaO2, etc.) mainly dominates the ORR activity/stability and battery performance. However, little success in regulating the stability of the superoxides has been achieved due to their highly reactive characteristics. Herein, we identified and modulated the stability of superoxides by introducing anthraquinone derivatives as cocatalysts which functioned as superoxide trapper adsorbing the superoxides generated via surface-mediated ORR and then transferring them from the solid catalyst surface into electrolyte. Among the studied trappers, 1,4-difluoroanthraquinone (DFAQ) with electron-withdrawing groups showed the highest adsorption towards superoxides and could efficiently stabilize LiO2 in electrolyte, which greatly promoted the surface-mediated ORR rate and stability. This highlighted the magnitude of adsorption between the trapper and LiO2 on the ORR activity/stability. Using an aprotic Li-O2 battery as a model metal-O2 battery, the overall performance of the cell with DFAQ was substantially improved in terms of cell capacity, rate capability and cyclic stability. These results represent a significant advance in the understanding of ORR mechanisms and promoting the performance of metal-O2 batteries.
KW - adsorption energy
KW - lithium oxygen battery
KW - oxygen reduction reaction
KW - superoxide
UR - https://www.scopus.com/pages/publications/85102135882
U2 - 10.1007/s40843-020-1519-9
DO - 10.1007/s40843-020-1519-9
M3 - 文章
AN - SCOPUS:85102135882
SN - 2095-8226
VL - 64
SP - 870
EP - 879
JO - Science China Materials
JF - Science China Materials
IS - 4
ER -