Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe ...Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe CoN8@Gra not only possesses moderate adsorption energies towards Li2Snspecies,but also exhibits superior catalytic activity for both reduction and oxidation reactions of the sulfur cathode.Moreover,the metallic property of the diatomic catalysts can be well maintained after Li2Snadsorption,which could help the sulfur cathode to maintain high conductivity during the whole charge–discharge process.Given these exceptional properties,it is expected that Fe CoN8@Gra could be a promising diatomic catalyst for Li–S batteries and afford insights for further development of advanced Li–S batteries.展开更多
Spinel Li CoMnO4 is prepared by solid-state reaction and its magnetic properties are comprehensively studied by direct current（DC） and alternating current（AC） susceptibilities, isothermal remanent magnetizations, ...Spinel Li CoMnO4 is prepared by solid-state reaction and its magnetic properties are comprehensively studied by direct current（DC） and alternating current（AC） susceptibilities, isothermal remanent magnetizations, and magnetic hysteresis.Fitting to the Curie–Weiss law by using high-temperature zero-field-cooled susceptibility confirms a low-spin state of Co^3＋with S = 0. Both the fitting parameters first increase and then tend to be saturated at high magnetic fields through using isothermal remanent magnetizations, which suggests a spin glass transition at low temperature. AC susceptibility study also supports this conclusion since the frequency dependence of peak position and intensity follows the tendency of a spin glass transition. The origin of the spin-glass transition in Li CoMnO4 might be attributed to a spatial segregation between non-magnetic Co^3＋regions and spin glass ordered regions of Mn^4＋ions.展开更多
基金the National Natural Science Foundation of China(Grant Nos.51972140 and 51903164)the Fund from Science and Technology Department of Jilin Province,China(Grant No.20200201069JC).
文摘Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries.Our results demonstrate that Fe CoN8@Gra not only possesses moderate adsorption energies towards Li2Snspecies,but also exhibits superior catalytic activity for both reduction and oxidation reactions of the sulfur cathode.Moreover,the metallic property of the diatomic catalysts can be well maintained after Li2Snadsorption,which could help the sulfur cathode to maintain high conductivity during the whole charge–discharge process.Given these exceptional properties,it is expected that Fe CoN8@Gra could be a promising diatomic catalyst for Li–S batteries and afford insights for further development of advanced Li–S batteries.
基金Project supported by the National Key Basic Research Program of China(Grant No.2015CB251103)the Development Program of Science and Technology of Jilin Province+2 种基金China(Grant No.20140101093JC)the Program of Science and Technology of Jilin CityChina(Grant No.201434006)
文摘Spinel Li CoMnO4 is prepared by solid-state reaction and its magnetic properties are comprehensively studied by direct current（DC） and alternating current（AC） susceptibilities, isothermal remanent magnetizations, and magnetic hysteresis.Fitting to the Curie–Weiss law by using high-temperature zero-field-cooled susceptibility confirms a low-spin state of Co^3＋with S = 0. Both the fitting parameters first increase and then tend to be saturated at high magnetic fields through using isothermal remanent magnetizations, which suggests a spin glass transition at low temperature. AC susceptibility study also supports this conclusion since the frequency dependence of peak position and intensity follows the tendency of a spin glass transition. The origin of the spin-glass transition in Li CoMnO4 might be attributed to a spatial segregation between non-magnetic Co^3＋regions and spin glass ordered regions of Mn^4＋ions.
