镁空气电池用Mg-0.5Bi-0.5Ag合金挤压态的组织特性与放电性能研究  

The study on microstructure and discharge properties of extruded Mg-0.5Bi-0.5Ag alloy for Mg-air batteries

作　　者：冯瑨 陈宇航 蔡宸旸 赵钒旭 史佼艳 王林欣 程伟丽[2,3] FENG Jin;CHEN Yu-hang;CAI Chen-yang;ZHAO Fan-xu;SHI Jiao-yan;WANG Lin-xin;CHENG Wei-li(Zong Fu college,Taiyuan University of Technology,Taiyuan 030024;School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024;Shanxi key Laboratory of Advanced Magnesium-Based Materials,Taiyuan University of Technology,Taiyuan 030024)

机构地区：[1]太原理工大学院宗复学院,山西太原030024 [2]太原理工大学材料科学与工程学院,山西太原030024 [3]太原理工大学山西省先进镁基材料重点实验室,山西太原030024

出　　处：《轻合金加工技术》2022年第4期43-50,共8页Light Alloy Fabrication Technology

基　　金：国家级大学生创新创业项目(202110112047);山西省应用基础研究计划项目(自由探索类,202103021224049);山西省科技重大专项(20191102007,20191102008)。

摘　　要：采用XRD、OM与SEM分析了Mg-0.5Bi-0.5Ag合金挤压态的微观组织特征,利用动电位极化、电化学阻抗谱以及镁空气电池测试研究了合金的电化学行为以及作为阳极时的放电性能,揭示了合金的组织特性与放电性能的关系。结果表明:挤压态的Mg-0.5Bi-0.5Ag合金的组织由完全动态再结晶晶粒组成,平均晶粒尺寸为9.94μm。合金主要包含α-Mg相和微量的纳米级Mg_(3)Bi_(2)相。在镁空气电池的测试中,挤压态的Mg-0.5Bi-0.5Ag合金阳极在2.5 mA/cm^(2)和5.0 mA/cm^(2)的电流密度下显示出了平稳的放电过程,电池电压达到了1.356 3 V和1.315 7 V。此外,该合金作为阳极时在20 mA/cm^(2)的电流密度下展示出了高的阳极效率和能量密度,分别达到了53.11%和21.40 mW/cm^(2)。挤压态Mg-0.5Bi-0.5Ag合金作为阳极时优异的放电性能主要与均匀的微观组织、弱的织构、优异的电化学活性以及Ag在电极表面的再沉积有关。The extruded Mg-0.5 Bi-0.5 Ag alloy was prepared,and the microstructure characteristics were analyzed by XRD,OM and SEM.The electrochemical behaviors of Mg-0.5 Bi-0.5 Ag alloy and its discharge performance as anodes were studied systematically by potentiodynamic polarization,EIS and the Mg-air batteries testing system.Besides,the influence of the microstructure on the discharge performance was illustrated.The results indicate that the extruded Mg-0.5 Bi-0.5 Ag alloy is composed of completely dynamic recrystallized grains with an average grain size of 9.94 μm.The alloy mainly contains α-Mg phase and nanoscale Mg_(3)Bi_(2) phase with low volume fraction.In the test of Mg-air battery,the extruded Mg-0.5 Bi-0.5 Ag anode shows a stable discharge process at current densities of 2.5 mA/cm~2 and 5.0 mA/cm~2,and the battery voltage reached 1.356 3 V and 1.315 7 V.In addition,the anodes also show the high anodic efficiency and energy density at a current density of 20 mA/cm~2,reaching 53.11% and 21.40 mW/cm~2,respectively.The excellent discharge performance of the Mg-0.5 Bi-0.5 Ag alloy as anodes is mainly related to the uniform microstructure,mitigated texture intensity,high electrochemical activity and the re-deposition of Ag on the electrode surface.

关 键 词：镁空气电池 Mg-0.5Bi-0.5Ag合金 电化学行为 放电性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG379[金属学及工艺—金属材料]