Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the e...Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the electrochemical properties of lithium–oxygen batteries(LOBs), especially the cycling performance, a high-efficiency cathode catalyst is the most important component.Hence, we aim to demonstrate that CuCr_2O_4@rGO(CCO@rGO) nanocomposites, which are synthesized using a facile hydrothermal method and followed by a series of calcination processes, are an effective cathode catalyst. The obtained CCO@rGO nanocomposites which served as the cathode catalyst of the LOBs exhibited an outstanding cycling performance for over 100 cycles with a fixed capacity of 1000 mAh g^(-1) at a current density of 200 mA g^(-1). The enhanced properties were attributed to the synergistic effect between the high catalytic efficiency of the spinel-structured CCO nanoparticles, the high specific surface area, and high conductivity of the rGO.展开更多
Theoretical simulation of the adsorption and dissociation of two NO molecules at the Cu^2＋, Cr^3＋ and bridge Cr^3＋ sites （b-Cr^3＋） on the normal spinel CuCr2O4 （100） surface has been carried out by density fun...Theoretical simulation of the adsorption and dissociation of two NO molecules at the Cu^2＋, Cr^3＋ and bridge Cr^3＋ sites （b-Cr^3＋） on the normal spinel CuCr2O4 （100） surface has been carried out by density functional theory calculations. The results show that the formed N-down and O-down NO dimers are negatively charged. The formation of stable O-down dimers on the surface leads to the great elongation of N-O bond, which contributes to the NO reduction. The transition-state calculations indicate that the decomposition of O-down NO dimer at the b-Cr^3＋ site is most favorable and N2O is the major reduction product.展开更多
基金jointly supported by National Science Foundation of China (Grant Numbers: 11572271 and 51302236)the Principal Fund of Xiamen University (Hosted by Guanghui Yue, 2018)
文摘Rechargeable lithium–oxygen batteries have been considered as a promising energy storage technology because of their ultra-high theoretical energy densities which are comparable to gasoline. In order to improve the electrochemical properties of lithium–oxygen batteries(LOBs), especially the cycling performance, a high-efficiency cathode catalyst is the most important component.Hence, we aim to demonstrate that CuCr_2O_4@rGO(CCO@rGO) nanocomposites, which are synthesized using a facile hydrothermal method and followed by a series of calcination processes, are an effective cathode catalyst. The obtained CCO@rGO nanocomposites which served as the cathode catalyst of the LOBs exhibited an outstanding cycling performance for over 100 cycles with a fixed capacity of 1000 mAh g^(-1) at a current density of 200 mA g^(-1). The enhanced properties were attributed to the synergistic effect between the high catalytic efficiency of the spinel-structured CCO nanoparticles, the high specific surface area, and high conductivity of the rGO.
基金the National Natural Science Foundation of China (No. 20673019)the Important Special Foundation of Fujian Province (No. 2005HZ01-2-6)Natural Education Department Foundation of PhD Unit (No. 20050386003)
文摘Theoretical simulation of the adsorption and dissociation of two NO molecules at the Cu^2＋, Cr^3＋ and bridge Cr^3＋ sites （b-Cr^3＋） on the normal spinel CuCr2O4 （100） surface has been carried out by density functional theory calculations. The results show that the formed N-down and O-down NO dimers are negatively charged. The formation of stable O-down dimers on the surface leads to the great elongation of N-O bond, which contributes to the NO reduction. The transition-state calculations indicate that the decomposition of O-down NO dimer at the b-Cr^3＋ site is most favorable and N2O is the major reduction product.
