| In recent years,there have been successful studies into the development of cathode materials for lithium/sodium-ion batteries.Therefore,many researchers have focused on exploring potential suitable anode materials for future lithium/sodium-ion batteries.Among the many suitable anode materials for lithium/sodium-ion batteries,antimony-based anode materials have received significant attention owing to its high theoretical specific capacity and superior lithium/sodium-storage performance.Nevertheless,the drawbacks of their low initial coulombic efficiency,poor rate capability and cyclic durability problems have always been the focus of the researchers,which also limit the practical uses of these anodes.This dissertation particularly investigated the preparation methods,structural characters,technological conditions and the electrochemical performance of the antimony-based anode materials.And the main works are as follows:1.Antimony oxychlorides submicro rods anode materials have been successfully synthesized by a simple and facile hydrothermal reaction.This anode material contained the monoclinic Sb4O5Cl2 phase,Sb8O11Cl2 phase and the orthorhombic Sb2S3 phase.The crystal structure of main phase Sb4O5Cl2 and Sb8O11Cl2 are layered structures,this structure is probably beneficial for the diffusion of Li+/Na+.The research results proved that the antimony oxychlorides anode material exhibits a prominent cycle performance.It can deliver a high initial discharge capacity of 1355.6 mAh g-1 at a current density of 50 mA g-1 in the voltage range of 0.01-2.0 V(vs.Li/Li+).After 50 cycles,the discharge specific capacity is as high as 694 mAh g-1,and the discharge specific capacity remains 401 mAh g-1 after 100 cycles.What's more,antimony oxychlorides material also exhibits brilliant cycle property in sodium-ion batteries at a current density of 50 mA g-1 in the voltage range of 0.01-2.0 V(vs.Na/Na+),which has a high discharge capacity of 452 mAh g-1 after 50 cycles at a current density of 50 mA g-1.2.Hierarchical Sb2S3 hollow microspheres have been effectively synthesized through a template-free method employing L-cysteine and SbCl3 as raw materials without adding any surfactants.As expected,the Sb2S3 hollow microspheres exhibit superior lithium/sodium-storage capacity and outstanding rate property.The prepared Sb2S3 hollow microsphere anode material can deliver a discharge capacity of 674 mAh g-1 after 50 cycles at a current density of 200 mA g-1 in the voltage range of 0.01-2.0 V(vs.Li/Li+).Sb2S3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 mAh g-1 after 50 cycles at a current density of 200 mA g-1 in the voltage range of 0.01-2.0 V(vs.Na/Na+).The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture,and the outstanding stability property is attributed to the sufficient interior void space of hollow microspheres,which can buffer the volume expansion.3.The porous Sb2S3/C composite with uniform size and superior dispersity are designed and prepared by the electrospinning technique.The results showed that Sb2S3/C composite has excellent cycle stability as the anode material of sodium-ion batteries.The porous structure of the nanofibers can increase the contact area between the electrolyte and electrode,and provide extra active sites for the Na+ storage.The first discharge/charge capacity of Sb2S3/C composite is 816/432 mAh g-1,at a current density of 50 mA g-1 in the voltage range of 0.01-2.0 V(vs.Na/Na+).However,at a current density of 500 mA g-1,the discharge specific capacity remains 289 mAh g-1 after 100 cycles,and the coulomb efficiency has been stable at around 99%.It can be observed that the capacity decay of the material occurs mainly in the first 10 cycles,followed by a good cycle performance.The specific capacity and rate performance of the Sb2S3/C composite material need to be further improved. |
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