Hierarchical Structural Design And Electrochemical Performance Of Antimony-based Anode Materials For Sodium-ion Batteries

With the development of modern industries,the energy crisis is becoming one of the most urgent issues which need to be resolved in our life.Effective utilization of these energy demands highly-efficient energy storage systems.Among these potential candidates,sodium-ion batteries（SIBs）have drawn much attention.The alloying electrode of Sb has been regarded as one promising anode for sodium storage thanks to its multi-electron reaction capacity,a moderate voltage plateau,and high electrical conductivity.However,huge volume change upon cycling,especially for sodium storage,usually causes the loss of electrical connection between active components and their delamination from the traditional current collector,thus leading to rapid capacity decay.The main contents of this paper are as follows:（1）Three dimensional（3D）macro-/mesoporous antimony electrodes are prepared by co-electrodeposition of Zn-Sb alloys using 3D porous Cu as the substrate coupled with selective corrosion of Zn,and their sodium storage behaviors are evaluated.The effect of electrodeposition electrode potentials on the electrochemical performance of 3D macro-/mesoporous Sb is investigated.The result indicates the 3D macro-/mesoporous Sb prepared by dealloying of macroporous Zn-Sb electrodeposited at-1.4 V（vs.SCE）delivers the best electrochemical performance.It remains 545 mAh g^-1 after 5 cycles at 66 mA g^-1 followed 200cycles at 330 mA g^-1.Even at a high current density of 3300 mA g^-1,the 3D macro-/meso Sb demonstrates high capacity retention of 82.8%compared with that at 100 mA g^-1.（2）A three-dimensional Cu nanowire array was constructed by anodization and subsequent high-temperature reduction,and then Sb was electrodeposited on the surface.The so-formed hierarchical 3D anode with interconnected 3D micrometer-sized pores and abundant voids between nanowires,not only effectively accommodates the structural strains during repeated cycling,but also ensures the structural integrity and contributes to a uniform ion/electron scattered distribution throughout the whole surface.When employed as anodes for SIBs,the obtained electrode shows a high capacity of 605.3 mAh g^-1 at 330 mA g^-1 and is maintained 561.1 mAh g^-1（capacity retention rate 92.7%）over 200 cycles.It also demonstrates high capacity retention of 84.8%s even at a high current density of 3300 mA g^-1.