Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile so...Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile solvothermal method involving a thermal-treatment at 800°C.When evaluated as an anode material for potassium ion batteries,MoSe_(2)/MoO_(3-x)@r GO delivers 248.2 m A h g^(-1)after 50 cycles at 0.2 A g^(-1) with a capacity retention of 84.6%and 182.9 m A h g^(-1)after 150 cycles at 1.0 A g^(-1) with a capacity retention of almost 61.2%,superior to those of bare MoSe_(2)or MoSe_(2)@r GO composites.Analysis from electrochemical measurements,the amorphous MoO_(3-x)containing oxygen vacancies could not only effectively buffer the self-aggregation of MoSe_(2)nanosheets but also provides lots of accessible active sites for potassium ion storage.Additionally,the open channels in the amorphous MoO_(3-x) phase lead to easier ion hopping and smaller diffusion barriers.Furthermore,the built-in electric field at the interface would be beneficial for electron transfer and K-ion migration across the hetero-junction interface.Moreover,larger dielectric polarization induced by the high relative permittivity of amorphous MoO_(3-x) would reduce charge transfer resistance and enhance K-ion migration across electric double-layer.Our work provides new insight into the enhanced performance of anode material coated by an amorphous layer with large relative permittivity.展开更多
基金the Natural Science Foundations of China(Nos.12174057,22179020)Natural Science Foundation of Fuccccjian Province(No.2021L3011)Fujian Natural Science Foundation for Distinguished Young Scholars(No.2020J06042)。
文摘Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile solvothermal method involving a thermal-treatment at 800°C.When evaluated as an anode material for potassium ion batteries,MoSe_(2)/MoO_(3-x)@r GO delivers 248.2 m A h g^(-1)after 50 cycles at 0.2 A g^(-1) with a capacity retention of 84.6%and 182.9 m A h g^(-1)after 150 cycles at 1.0 A g^(-1) with a capacity retention of almost 61.2%,superior to those of bare MoSe_(2)or MoSe_(2)@r GO composites.Analysis from electrochemical measurements,the amorphous MoO_(3-x)containing oxygen vacancies could not only effectively buffer the self-aggregation of MoSe_(2)nanosheets but also provides lots of accessible active sites for potassium ion storage.Additionally,the open channels in the amorphous MoO_(3-x) phase lead to easier ion hopping and smaller diffusion barriers.Furthermore,the built-in electric field at the interface would be beneficial for electron transfer and K-ion migration across the hetero-junction interface.Moreover,larger dielectric polarization induced by the high relative permittivity of amorphous MoO_(3-x) would reduce charge transfer resistance and enhance K-ion migration across electric double-layer.Our work provides new insight into the enhanced performance of anode material coated by an amorphous layer with large relative permittivity.
