Activation of 2D MoS_(2) electrodes induced by high-rate lithiation processes  

作　　者：Tianzhu Liu Georgian Melinte Oleksandr Dolotko Michael Knapp Beatriz Mendoza-Sánchez 

机构地区：[1]Institute for Applied Materials-Energy Storage Systems(IAM-ESS),Karlsruhe Institute of Technology(KIT),Eggenstein-Leopoldshafen D-76344,Germany [2]Karlsruhe Nano Micro Facility(KNMF),Karlsruhe Institute of Technology(KIT),Eggenstein-Leopoldshafen D-76344,Germany [3]Helmholtz-Institute Ulm for Electrochemical Energy Storage(HIU),Ulm 89081,Germany

出　　处：《Journal of Energy Chemistry》2023年第3期56-70,I0003,共16页能源化学（英文版）

基　　金：financial support from the China Scholarship Council(CSC grant.201808330389)。

摘　　要：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.

关 键 词：2D MoS_(2) Liquid-phase exfoliation Spray-deposition Conversion processes Activation mechanisms Energy storage mechanisms 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ136.12[化学工程—无机化工]