The shift to clean energy is crucial in mitigating the harmful effects of fossil fuels on the environment.Nevertheless,as we embrace clean energy sources,particularly solar and wind energies,high-energy-density storag...The shift to clean energy is crucial in mitigating the harmful effects of fossil fuels on the environment.Nevertheless,as we embrace clean energy sources,particularly solar and wind energies,high-energy-density storage devices like lithium and sodium-oxygen batteries are essential.However,challenges such as the irreversibility of lithium and sodium peroxides and their non-conductivity nature on the cathode electrode hinder practical use.2D materials,particularlyβ_(12)-borophene,show promise in addressing these challenges.In this study,we used density functional theory to thoroughly investigate the adsorption mechanisms of alkali-metal peroxides and their impact on the electronic properties of theβ_(12)-borophene.Our results revealed adsorption energies of-3.71 and-3.54 eV for Li_(2)O_(2)and Na_(2)O_(2),respectively,showing that the adsorbed peroxides are stable and unlikely to decompose into the electrolyte.The calculated Gibbs free energy changes that revealed low overpotentials of 1.03 V for Li_(2)O_(2)and 1.61 V for Na_(2)O_(2).Moreover,even with increased concentrations of peroxides on the surface,β_(12)-borophene retained its ability to adsorb additional peroxides,achieving theoretical voltages of 2.60 V for Li_(2)O_(2)and 2.04 V for Na_(2)O_(2).Notably,the metallic nature ofβ_(12)remained stable despite the adsorption of peroxides,evidenced by an increase in electronic states around the Fermi level and the overlap of the valence and conduction bands.Furthermore,thermal stability analysis at 300 K confirmed that the structure ofβ_(12)-borophene remained intact,reinforcing its suitability as a cathode at standard temperature of the battery.The low diffusion energy barriers of 1.04 and 0.92 eV were obtained for Li_(2)O_(2)and Na_(2)O_(2),respectively,suggesting a high rate of peroxides migration on the substrate surface.The dissociation energy barriers for Li_(2)O_(2)and Na_(2)O_(2)were found to be minimal at 1.86 and 1.69 eV,respectively,indicating the catalytic effects and enhancing electrochemical processes.Our findings suggest thatβ_(12)-borophene can be a potential cathode electrode for the next-generation lithium and sodium-oxygen batteries.展开更多
基金support from the University of Pretoria,Department of Innovation and Research.
文摘The shift to clean energy is crucial in mitigating the harmful effects of fossil fuels on the environment.Nevertheless,as we embrace clean energy sources,particularly solar and wind energies,high-energy-density storage devices like lithium and sodium-oxygen batteries are essential.However,challenges such as the irreversibility of lithium and sodium peroxides and their non-conductivity nature on the cathode electrode hinder practical use.2D materials,particularlyβ_(12)-borophene,show promise in addressing these challenges.In this study,we used density functional theory to thoroughly investigate the adsorption mechanisms of alkali-metal peroxides and their impact on the electronic properties of theβ_(12)-borophene.Our results revealed adsorption energies of-3.71 and-3.54 eV for Li_(2)O_(2)and Na_(2)O_(2),respectively,showing that the adsorbed peroxides are stable and unlikely to decompose into the electrolyte.The calculated Gibbs free energy changes that revealed low overpotentials of 1.03 V for Li_(2)O_(2)and 1.61 V for Na_(2)O_(2).Moreover,even with increased concentrations of peroxides on the surface,β_(12)-borophene retained its ability to adsorb additional peroxides,achieving theoretical voltages of 2.60 V for Li_(2)O_(2)and 2.04 V for Na_(2)O_(2).Notably,the metallic nature ofβ_(12)remained stable despite the adsorption of peroxides,evidenced by an increase in electronic states around the Fermi level and the overlap of the valence and conduction bands.Furthermore,thermal stability analysis at 300 K confirmed that the structure ofβ_(12)-borophene remained intact,reinforcing its suitability as a cathode at standard temperature of the battery.The low diffusion energy barriers of 1.04 and 0.92 eV were obtained for Li_(2)O_(2)and Na_(2)O_(2),respectively,suggesting a high rate of peroxides migration on the substrate surface.The dissociation energy barriers for Li_(2)O_(2)and Na_(2)O_(2)were found to be minimal at 1.86 and 1.69 eV,respectively,indicating the catalytic effects and enhancing electrochemical processes.Our findings suggest thatβ_(12)-borophene can be a potential cathode electrode for the next-generation lithium and sodium-oxygen batteries.
