The inherent catalytic anisotropy of two-dimensional(2D) materials has limited the enhancement of LiO_(2) batteries(LOBs) performance due to the significantly different adsorption energies on 2D and edge surfaces.Tuni...The inherent catalytic anisotropy of two-dimensional(2D) materials has limited the enhancement of LiO_(2) batteries(LOBs) performance due to the significantly different adsorption energies on 2D and edge surfaces.Tuning the adsorption strength in 2D materials to the reaction intermediates is essential for achieving high-performance LOBs.Herein,a MnS/MoS_(2) heterostructure is designed as a cathode catalyst by adjusting the adsorption behavior at the surface.Different from the toroidal-like discharge products on the MoS_(2) cathode,the MnS/MoS_(2) surface displays an improved adsorption energy to reaction species,thereby promoting the growth of the film-like discharge products.MnS can disturb the layer growth of MoS_(2),in which the stack edge plane features a strong interaction with the intermediates and limits the growth of the discharge products.Experimental and theoretical results confirm that the MnS/MoS_(2) heterostructure possesses improved electron transfer kinetics at the interface and plays an important role in the adsorption process for reaction species,which finally affects the morphology of Li_2O_(2),In consequence,the MnS/MoS_(2) heterostructure exhibits a high specific capacity of 11696.0 mA h g^(-1) and good cycle stability over 1800 h with a fixed specific capacity of 600 mA h g^(-1) at current density of100 mA g^(-1) This work provides a novel interfacial engineering strategy to enhance the performance of LOBs by tuning the adsorption properties of 2D materials.展开更多
g3(green gas for gird)环保气体(C_(4)F_(7)N/CO_(2)混合)作为SF_(6)最具潜力的新型环保绝缘替代气体,近几年来受到了广泛关注.通过分析g3气体绝缘组合开关设备中的分解组分来检测局部放电、过热等缺陷故障,对于电力设备运行状态的评...g3(green gas for gird)环保气体(C_(4)F_(7)N/CO_(2)混合)作为SF_(6)最具潜力的新型环保绝缘替代气体,近几年来受到了广泛关注.通过分析g3气体绝缘组合开关设备中的分解组分来检测局部放电、过热等缺陷故障,对于电力设备运行状态的评估和诊断具有重要作用.本文提出利用Si原子掺杂改性来提高MoS_(2)的气敏和吸附性能,并基于密度泛函理论(DFT)的计算方法,通过吸附能、电荷转移、态密度和局部态密度等参数指标,探究了本征MoS_(2)、Si改性MoS_(2)(Si-MoS_(2))对g3气体典型分解组分—COF_(2)、CF_(4)、CF_(3)CN的吸附气敏机理.分析表明Si原子在MoS_(2)表面具有稳定的掺杂结构,相比本征MoS_(2),Si原子改性之后的MoS_(2)的导电性得到了有效增强;Si-MoS_(2)对COF_(2)、CF_(4)气体表现出强化学吸附作用,对CF_(3)CN为弱物理吸附,吸附强度CF_(4)>COF_(2)>CF_(3)CN,且在吸附过程中Si-MoS_(2)总是作为电子供体,将电子转移到气体分子;Si改性MoS_(2)对g3气体分解组分具有选择吸附性,为检测CF_(4)、COF_(2)气体的MoS_(2)高性能气敏传感器的研制提供了理论上的基础;研究结果在减少温室气体的排放、提高GIS(Gas Insulated Switchgear)的运行稳定性等方面同样具有重要意义.展开更多
基金supported by the National Natural Science Foundation of China (52173286, 52207249)Major basic research project of Natural Science Foundation of Shandong Province (ZR2023ZD12)+1 种基金the State Key Laboratory of Marine Resource Utilization in South China Sea (Hainan University) (MRUKF2023013)Open Program of Guangxi Key Laboratory of Information Materials (221024-K)。
文摘The inherent catalytic anisotropy of two-dimensional(2D) materials has limited the enhancement of LiO_(2) batteries(LOBs) performance due to the significantly different adsorption energies on 2D and edge surfaces.Tuning the adsorption strength in 2D materials to the reaction intermediates is essential for achieving high-performance LOBs.Herein,a MnS/MoS_(2) heterostructure is designed as a cathode catalyst by adjusting the adsorption behavior at the surface.Different from the toroidal-like discharge products on the MoS_(2) cathode,the MnS/MoS_(2) surface displays an improved adsorption energy to reaction species,thereby promoting the growth of the film-like discharge products.MnS can disturb the layer growth of MoS_(2),in which the stack edge plane features a strong interaction with the intermediates and limits the growth of the discharge products.Experimental and theoretical results confirm that the MnS/MoS_(2) heterostructure possesses improved electron transfer kinetics at the interface and plays an important role in the adsorption process for reaction species,which finally affects the morphology of Li_2O_(2),In consequence,the MnS/MoS_(2) heterostructure exhibits a high specific capacity of 11696.0 mA h g^(-1) and good cycle stability over 1800 h with a fixed specific capacity of 600 mA h g^(-1) at current density of100 mA g^(-1) This work provides a novel interfacial engineering strategy to enhance the performance of LOBs by tuning the adsorption properties of 2D materials.
文摘g3(green gas for gird)环保气体(C_(4)F_(7)N/CO_(2)混合)作为SF_(6)最具潜力的新型环保绝缘替代气体,近几年来受到了广泛关注.通过分析g3气体绝缘组合开关设备中的分解组分来检测局部放电、过热等缺陷故障,对于电力设备运行状态的评估和诊断具有重要作用.本文提出利用Si原子掺杂改性来提高MoS_(2)的气敏和吸附性能,并基于密度泛函理论(DFT)的计算方法,通过吸附能、电荷转移、态密度和局部态密度等参数指标,探究了本征MoS_(2)、Si改性MoS_(2)(Si-MoS_(2))对g3气体典型分解组分—COF_(2)、CF_(4)、CF_(3)CN的吸附气敏机理.分析表明Si原子在MoS_(2)表面具有稳定的掺杂结构,相比本征MoS_(2),Si原子改性之后的MoS_(2)的导电性得到了有效增强;Si-MoS_(2)对COF_(2)、CF_(4)气体表现出强化学吸附作用,对CF_(3)CN为弱物理吸附,吸附强度CF_(4)>COF_(2)>CF_(3)CN,且在吸附过程中Si-MoS_(2)总是作为电子供体,将电子转移到气体分子;Si改性MoS_(2)对g3气体分解组分具有选择吸附性,为检测CF_(4)、COF_(2)气体的MoS_(2)高性能气敏传感器的研制提供了理论上的基础;研究结果在减少温室气体的排放、提高GIS(Gas Insulated Switchgear)的运行稳定性等方面同样具有重要意义.
