聚乙烯亚胺电解液添加剂对锌离子电池性能的影响

Effect of Polyethyleneimine Electrolyte Additives on Performance of Zinc Ion Batteries

针对电池在循环过程中存在副反应和枝晶生长的问题,以聚乙烯亚胺作为电解液添加剂,探究其对锌离子电池性能的影响。对有无添加剂的电池循环后的电极进行X射线衍射(XRD)、扫描电子显微镜(SEM)以及电化学分析。研究结果表明:聚乙烯亚胺添加剂在锌负极表面形成的吸附层会阻碍副反应,同时促进锌离子均匀沉积,并最终影响电化学性能。当添加剂质量浓度为0.1 g·L^(-1)时,Zn‖Cu电池循环600圈后,库仑效率稳定保持在99.7%以上。在0.2 A·g^(-1)条件下,Zn‖MnO_(2)全电池放电比容量即使在100圈后仍然保持在150 mAh·cm^(-2)。

In response to the challenges of side reactions and dendrite growth during the cycling process of zinc ion batteries(ZIBs),polyethyleneimine was used as an electrolyte additive and its effect on the performance of ZIBs was investigated in this work.The electrodes were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM),and electrochemical analysis after circulation of the batteries with and without additives.The results show that the formation of adsorption layer of polyethyleneimine additive on the surface of zinc anode will hinder the by-reactions while promoting the uniform deposition of zinc ions,and finally affect the electrochemical performance.When the additive content is 0.1 g·L^(-1),the coulombic efficiency of the Zn‖Cu cell remains above 99.7% after 600 cycles.The discharge specific capacity of the Zn‖MnO_(2) cell remains at 150 mAh·cm^(-2) after 100 cycles at 0.2 A·g^(-1).