三维多孔Ni_(3)S_(2)电极的形貌调控及其储钠性能  

Shape modulation of three-dimensional porous Ni_(3)S_(2)electrodes for enhanced sodium storage performance

作　　者：樊小勇[1] 张露露 孙瑞波 FAN Xiaoyong;ZHANG Lulu;SUN Ruibo(School of Materials Science and Engineering,Chang'an University,Xi'an 710061,Shaanxi,China)

机构地区：[1]长安大学材料科学与工程学院,陕西西安710061

出　　处：《陕西师范大学学报（自然科学版）》2023年第4期87-96,共10页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：陕西省国际合作项目(2020KW024)。

摘　　要：为解决Ni_(3)S_(2)钠离子电池负极在循环过程中产生的体积膨胀、材料粉化及循环稳定性差的问题,以三维多孔镍为基底,通过控制水热时间调控了Ni_(3)S_(2)电极形貌,研究了不同微观形貌对其电化学性能的影响。结果表明:在短水热时间内,三维多孔Ni_(3)S_(2)电极趋向于生成纳米片阵列;随着水热时间的增加,纳米片逐渐卷曲为纳米管阵列,最终完全转变为纳米管阵列结构。纳米管阵列在循环过程中具有更稳定的结构,确保了电子和离子的高速传输。三维多孔Ni_(3)S_(2)纳米管阵列电极具有最优的长循环性能和倍率性能,在100 mA/g的电流密度下循环200次,比容量保持279.1 mA·h/g,保持率达到53.7%,远高于三维多孔Ni_(3)S_(2)纳米片阵列电极(26.6%)和三维多孔纳米片和纳米管复合形貌的Ni_(3)S_(2)电极(38.7%)。当电流密度增大到1.6 A/g时,三维多孔Ni_(3)S_(2)纳米管阵列电极仍可提供291.1 mA·h/g的比容量。Ni_(3)S_(2) anode of sodium-ion batteries suffers severe volume changes and materials pulverization during cycling,resulting in poor cycle stability.This work selects three-dimensional porous nickel as the substrate and simultaneously controls the hydrothermal time to regulate the morphology of the Ni_(3)S_(2) electrode.The results show that the three-dimensional porous Ni_(3)S_(2) electrode tends to generate nanosheet arrays in a short hydrothermal time.With the increase of hydrothermal time,the nanosheet arrays partially transformed into nanotube arrays and eventually completely transformed into nanotube arrays.Due to the high stability of nanotube structure during cycling,three-dimensional porous Ni_(3)S_(2) nanotube array electrode shows the best long cycle performance and rate performance.It delivers a specific capacity of 279.1 mA·h/g after 200 cycles at a current density of 100 mA/g with a retention of 53.7%,which was much higher than that of the three-dimensional porous Ni_(3)S_(2) nanosheet array electrode(26.6%)and the Ni_(3)S_(2) electrode with three-dimensional porous nanosheet/nanotube structure(38.7%).Even at a high current density of 1.6 A/g,the three-dimensional porous Ni_(3)S_(2) nanotube array electrode still provides a specific capacity of 291.1 mA·h/g.

关 键 词：钠离子电池 三维多孔 硫化镍 纳米片 纳米管 

分 类 号：O646[理学—物理化学]