MoS_(2) is a highly promising material for application in lithium-ion battery anodes due to its high theoretical capacity and low cost.However,problems with a fast capacity decay over cycling,especially at the first c...MoS_(2) is a highly promising material for application in lithium-ion battery anodes due to its high theoretical capacity and low cost.However,problems with a fast capacity decay over cycling,especially at the first cycles,and poor rate performance have deterred its practical implementation.Herein,electrodes comprised solely of few-layers 2D MoS_(2) nanosheets have been manufactured by scalable liquid-phase exfoliation and spray deposition methods.The long-standing controversy questioning the reversibility of conversion processes of MoS_(2)-based electrodes was addressed.Raman studies revealed that,in 2D MoS_(2) electrodes,conversion processes are indeed reversible,where nanostructure played a key role.Cycling of the electrodes at high current rates revealed an intriguing phenomenon consisting of a continuously increasing capacity after ca.100-200 cycles.This phenomenon was comprehensively addressed by a variety of electrochemical and microscopy methods that revealed underlying physical activation mechanisms that involved a range of profound electrode structural changes.Activation mechanisms delivered a capacitive electrode of a superior rate performance and cycling stability,as compared to the corresponding pristine electrodes,and to MoS_(2) electrodes previously reported.Herein,we have devised a methodology to overcome the problem of cycling stability of 2D MoS_(2) electrodes.Moreover,activation of electrodes constitutes a methodology that could be applied to enhance the energy storage performance of electrodes based on other 2D nanomaterials,or combinations thereof,strategically combining chemistries to engineer electrodes of superior energy storage properties.展开更多
The fabrication of the high speed steel matrix composites reinforced by WC particles utilizing the ultrasonicgas atomization and spray-deposition was studied. The change of microstware and mechanical Properties of the...The fabrication of the high speed steel matrix composites reinforced by WC particles utilizing the ultrasonicgas atomization and spray-deposition was studied. The change of microstware and mechanical Properties of thecomposites added WC Particles were investigated and analyzed as well. As some results, the WC particles exhibit tWomorphologies (spherical and angular) with different content of WC particles; and with the increase of content of WCparticles, the hardness of the composites increases, yet the bending strength appears a trend of decreasing.展开更多
基金Projects(2019YFA0708802, 2020YFA0711104) supported by the National Key R&D Program of ChinaProject(U21B6004) supported by the National Natural Science Foundation of ChinaProject(2021GK1040) supported by Major Project of Scientific Innovation of Hunan Province,China。
基金financial support from the China Scholarship Council(CSC grant.201808330389)。
文摘MoS_(2) is a highly promising material for application in lithium-ion battery anodes due to its high theoretical capacity and low cost.However,problems with a fast capacity decay over cycling,especially at the first cycles,and poor rate performance have deterred its practical implementation.Herein,electrodes comprised solely of few-layers 2D MoS_(2) nanosheets have been manufactured by scalable liquid-phase exfoliation and spray deposition methods.The long-standing controversy questioning the reversibility of conversion processes of MoS_(2)-based electrodes was addressed.Raman studies revealed that,in 2D MoS_(2) electrodes,conversion processes are indeed reversible,where nanostructure played a key role.Cycling of the electrodes at high current rates revealed an intriguing phenomenon consisting of a continuously increasing capacity after ca.100-200 cycles.This phenomenon was comprehensively addressed by a variety of electrochemical and microscopy methods that revealed underlying physical activation mechanisms that involved a range of profound electrode structural changes.Activation mechanisms delivered a capacitive electrode of a superior rate performance and cycling stability,as compared to the corresponding pristine electrodes,and to MoS_(2) electrodes previously reported.Herein,we have devised a methodology to overcome the problem of cycling stability of 2D MoS_(2) electrodes.Moreover,activation of electrodes constitutes a methodology that could be applied to enhance the energy storage performance of electrodes based on other 2D nanomaterials,or combinations thereof,strategically combining chemistries to engineer electrodes of superior energy storage properties.
文摘The fabrication of the high speed steel matrix composites reinforced by WC particles utilizing the ultrasonicgas atomization and spray-deposition was studied. The change of microstware and mechanical Properties of thecomposites added WC Particles were investigated and analyzed as well. As some results, the WC particles exhibit tWomorphologies (spherical and angular) with different content of WC particles; and with the increase of content of WCparticles, the hardness of the composites increases, yet the bending strength appears a trend of decreasing.
