Interface engineering strategy shows great promise in promoting the reaction kinetic and cycling performance in the field of electrochemical energy storage application.In this work,an in-situ interface growth strategy...Interface engineering strategy shows great promise in promoting the reaction kinetic and cycling performance in the field of electrochemical energy storage application.In this work,an in-situ interface growth strategy is proposed to introduce a robust and conducting MoGe_(2) alloy interphase between the electrochemical active Ge nanoparticle and flexible MoS_(2) nanosheets to modulate their Li-ion storage kinetics.The structural evolution processes of the Ge@MoGe_(2)@MoS_(2) composite are unraveled,during which the initially-generated Ge metals serve as a crucial reduction mediator in the formation of MoGe_(2) species bridging the Ge and MoS_(2).The as-generated MoGe_(2) interface,chemically bonding with both Ge and MoS_(2),possesses multi-fold merits,including the maintaining stable framework of electrochemically inactive Mo matrix to buffer the strain-stress effect and the"welding spot"effects to facilitate the efficient Li^(+)/e^(-)conduction.As well,the introduction of MoGe_(2) interface leads to a unique sequential lithiation/de^(-)lithiation process,namely in the order of the electrochemically active MoS_(2)-MoGe_(2)-Ge during lithiation and vice versa,during which the electrode strain could be more effectively released.Benefited from the robust and rigid MoGe_(2) interface,the delicately designed Ge@MoGe_(2)@MoS_(2) composite exhibits an improved charge/discharge performances(866.7 mAh g^(-1) at 5.0 A g^(-1) and 838.5 mAh g^(-1) after 400 cycles)while showing a high tap density of 1.23 g cm^(-3).The as-proposed in-situ interface growth strategy paves a new avenue for designing novel high-performance electrochemical energy storage materials.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51672146,21805157,51972187)the Natural Science Foundation of Shandong Province(ZR2018BEM011,ZR2019MEM043 and ZR2019MB037)+1 种基金the Key R&D project of Shandong Province(2019GGX103034)the Development Program in Science and Technology of Qingdao(19-6-2-12-cg)。
文摘Interface engineering strategy shows great promise in promoting the reaction kinetic and cycling performance in the field of electrochemical energy storage application.In this work,an in-situ interface growth strategy is proposed to introduce a robust and conducting MoGe_(2) alloy interphase between the electrochemical active Ge nanoparticle and flexible MoS_(2) nanosheets to modulate their Li-ion storage kinetics.The structural evolution processes of the Ge@MoGe_(2)@MoS_(2) composite are unraveled,during which the initially-generated Ge metals serve as a crucial reduction mediator in the formation of MoGe_(2) species bridging the Ge and MoS_(2).The as-generated MoGe_(2) interface,chemically bonding with both Ge and MoS_(2),possesses multi-fold merits,including the maintaining stable framework of electrochemically inactive Mo matrix to buffer the strain-stress effect and the"welding spot"effects to facilitate the efficient Li^(+)/e^(-)conduction.As well,the introduction of MoGe_(2) interface leads to a unique sequential lithiation/de^(-)lithiation process,namely in the order of the electrochemically active MoS_(2)-MoGe_(2)-Ge during lithiation and vice versa,during which the electrode strain could be more effectively released.Benefited from the robust and rigid MoGe_(2) interface,the delicately designed Ge@MoGe_(2)@MoS_(2) composite exhibits an improved charge/discharge performances(866.7 mAh g^(-1) at 5.0 A g^(-1) and 838.5 mAh g^(-1) after 400 cycles)while showing a high tap density of 1.23 g cm^(-3).The as-proposed in-situ interface growth strategy paves a new avenue for designing novel high-performance electrochemical energy storage materials.
