In-situ Construction And Electrochemical Properties Of Nanostructure Fe-based Chalcogenide

Owing to its high energy and power densities,environmental benignity and long lifespan,Lithium-ion batteries?LIBs?have been widely used.Currently,the mostly used commercial anode material,graphite,only delivered a low theoretical capacity of 372mAh g^-1,cannot satisfy the energy storage applications requiring for higher energy and power densities,such as electric vehicles?EVs?and hybrid electric vehicles?HEVs?.Therefore,it is necessary to explore alternative anode materials in order to solve these problems.Transmation metal sulfides?TMSs?are identified as most promising anode materials for lithium-ion batteries?LIBs?.Our work mainly investigated the electrochemical performances of Fe-based chalcogenide as anode materal for lithium-ion batteries?LIBs?.The as-follow contents were investigated.?1?The investigation of 3D-flowerlike FeS as anode material for high-rate lithium-ion batteries:the Fe-based flowerlike precursors were synthesized via a facile method,then proceeding procedure of sulfidation at high temperature.Finally,the 3D-flowerlike FeS composites were obtained.3D-flowerlike FeS exhibited excellent electrochemical performance as anode material for lithium-ion batteries?LIBs?,high-rate performance(delivered discharge specific capacity of 779.0 mAh g^-1 at a current density of 5 A g^-1)and cyclic stability(discharge specific capacity of 900 mAh g^-1 retained after cycling100 cycles at 1.0 A g^-1).?2?Rod-like Fe-N-Fe1-x S@C composites were successfully prepared through a one-step simultaneous sulfidation and nitridation of MIL-88A-Fe precursors.The synthesized Fe-N-C species can serve as polysulfides adsorbents and electrocatalysts,promoting the conversion reactions betwwen Fe1-x S and polysulfides.In addition,the porous rod-like structure can reduce the pathway of lithium ion,and nano-sized architectures also can alleviating the volume expansion.Therefore,rod-like Fe-N-Fe1-x S@C composites showed superior electrochemical performances,delivered high discharge specific capacity at a high rate(5 A g^-1,850.0 mAh g^-1)and cycling stability(retained discharge specific capacity of 900 mAh g^-1 after cycling 100 cycles at 1.0 A g^-1).?3?Rod-shaped Fe3Se4/C composites with porous structure were synthesized by a facile one-step solid-state reaction.The doped carbon not only created the special morphology and structure,but also improved the conductivity and structural stability.Therefore,rod-shaped Fe3Se4/C composites exhibited excellent electrochemical properties,high-rate performance(delivered discharge specific capacity of 329.1 mAh g^-1 at a current density of 5 A g^-1)and cycling stability(discharge specific capacity of434.4 mAh g^-1 retained after cycling 100 cycles at 1.0 A g^-1).