摘要
Nonaqueous Li-O2 batteries attract attention for their theoretical specific energy density.However,due to the difficulty of decomposition of Li2 O2,Li-O2 batteries have high charge overpotential and poor cycling life.So all kinds of catalysts have been studied on the cathode.Compared to heterogeneous solid catalysts,soluble catalysts achieve faster and more effective transport of electrons by reversible redox pairs.Here,we first report ruthenocene(Ruc) as a mobile redox mediator in a Li-O2 battery.0.01 mol/L Ruc in the electrolyte effectively reduces the charging voltage by 610 mV.Additionally,Ruc greatly increases the cycling life by four-fold(up to 83 cycles) with a simple ketjen black(KB) cathode.The results of SEM,XPS and XRD confirm that less discharge product residue accumulated after recharge.To verify the reaction mechanisms of the mediato r,free energy profiles of the possible reaction pathways based on DFT are provided.
基金
the National Natural Science Foundation of China (Nos.U1732111 and 21676241)
“The Recruitment Program of Global Youth Experts” from the Chinese government
the “Hundred Talents Program” of Zhejiang University
Hubei Natural Science Foundation of China (No.2018CFB531)
Self-determined Research Funds of CCNU from Colleges’ Basic Research and Operation of MOE (No.CCNU18TS045)。
