摘要
以ZIF-8为载体,将吸附-还原法与热处理相结合,制备SnO_(2)/ZnO材料并用作锌镍电池负极。通过优化热处理工艺获得粒径、形貌均匀的SnO_(2)/ZnO材料,然后通过XRD、SEM、循环伏安法和恒电流充放电测试研究SnO_(2)质量分数对SnO_(2)/ZnO材料物相结构、微观形貌及电化学性能的影响。研究结果表明:当温度为800℃,热处理时间为9 h时,所制备的SnO_(2)/ZnO材料物相单一,形貌均匀,平均粒径为22.4 nm;当SnO_(2)/ZnO材料中SnO_(2)质量分数从7.7%增加至23.0%时,颗粒粒径先减小,后团聚现象增加,用作电池负极时平均放电比容量先增加至600 mA·h/g后减小至535 mA·h/g,且电池极化先减小后增加,稳定性也随之先提升后变差;当SnO_(2)/ZnO材料中SnO_(2)的质量分数为15.1%时,用作锌镍电池负极所表现的性能最佳,即循环伏安曲线阴阳极峰电压差为0.281 0 V,第50圈的中值电压差为0.314 5 V,在659 mA/g的电流密度下循环时平均放电比容量为600 mA·h/g,200圈后的容量保持率为93.66%。锌负极的放电比容量及循环稳定性得到较大提升,主要是因为SnO_(2)在电池工作过程中形成金属锡,提高负极的析氢过电位,改善了负极的导电性。
As the anode materials for Zn/Ni batteries,SnO_(2)/ZnO materials were prepared using ZIF-8 as carrier by combining adsorption-reduction with heat treatment.Heat treatment process was optimized to obtain SnO_(2)/ZnO materials with uniform particle size and morphology.The effect of SnO_(2) mass fraction on the phase,morphology and electrochemical performance of SnO_(2)/ZnO materials was further studied through XRD,SEM,cyclic voltammetry and constant current charge/discharge tests.The results show that the prepared SnO_(2)/ZnO material has a single phase,uniform morphology with an average particle size of 22.4 nm when heat treatment temperature is at 800 ℃ for 9 h.The particle size of material decreases firstly and then increases in agglomeration when the mass fraction of SnO_(2) in the SnO_(2)/ZnO material increases from 7.7% to 23.0%.When the materials are used as the anode of the battery,the average capacity firstly increases to 600 mA·h/g and then decreases to 535 mA·h/g,and the battery polarization firstly decreases and then increases.The stability also increases firstly and then decreases.It is shown the best performance is achieved when SnO_(2)/ZnO materials with SnO_(2) mass fraction of 15.1% are used as anode for zinc-nickel battery.The voltage difference of cyclic voltammetry curve is 0.281 0 V.The average specific discharge capacity is 600 mA·h/g and the capacity retention rate is 93.66% at a current density of659 mA/g.The discharge specific capacity and cycle stability of the zinc anode are greatly improved,mainly because SnO_(2) could be reduced to metallic tin during battery operation,which increases the hydrogen evolution overpotential and improves the conductivity of the anode.
作者
程皓
郭伟昌
汪滔
李铮
田忠良
CHENG Hao;GUO Weichang;WANG Tao;LI Zheng;TIAN Zhongliang(School of Metallurgy and Environment,Central South University,Changsha 410083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第2期418-425,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51974380)。
关键词
锌负极
二氧化锡
锌镍电池
微观结构
电化学性能
zinc anode
SnO_(2)
Zn/Ni battery
microstructure
electrochemical performance
