Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (03): 427-432.DOI: 10.6023/A12110871 Previous Articles     Next Articles

Article

用于聚合物镍氢电池的新型PVA/SiO2碱性微孔聚合物电解质

陆霞, 吴仁香, 李波波, 朱云峰, 李李泉   

  1. 南京工业大学材料科学与工程学院 南京新模范马路5号 210009
  • 收稿日期:2012-11-05 出版日期:2013-03-14 发布日期:2013-02-01
  • 通讯作者: 李李泉 E-mail:lilq@njut.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.51171079,51071085),教育部高等学校博士学科点专项科研基金(No.20093221110008)和江苏高校优势学科建设工程项目(PAPD)资助.

Novel PVA/SiO2 Alkaline Micro-porous Polymer Electrolytes for Polymer Ni—MH Batteries

Lu Xia, Wu Renxiang, Li Bobo, Zhu Yunfeng, Li Liquan   

  1. College of Materials Science and Technology, Nanjing University of Technology, Nanjing 210009
  • Received:2012-11-05 Online:2013-03-14 Published:2013-02-01
  • Supported by:

    Project supported by National Natural Science Foundation of China (Nos. 51171079, 51071085), Specialized Research Fund for the Doctoral Program of High Education (No. 20093221110008) and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

New poly(vinyl alcohol)/silica (designated as PVA/SiO2) alkaline micro-porous polymer electrolytes (AMPEs) were prepared by soaking PVA/SiO2 micro-porous composite membranes, obtained by solution casting of PVA/PEG/SiO2 membrane in acetone solution, into an electrolyte solution of 6 mol/L KOH aqueous solution. The morphology and structure of PVA/SiO2 composite polymer membranes were characterized by scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The SEM photographs showed that the nano-SiO2 filler content was a crucial issue for the well-dispersed and optimal-sized pores which could storage charge carrier durably. Meanwhile, the crystalline of PVA decreased effectively for a large number of crystal defects and free volume appeared in the interface of inorganic particles and polymer for the addition of nano-SiO2 filler. The electrochemical properties of the AMPEs were measured by the alternating current impedance (AC impedance) and the cyclic voltammetry (CV) techniques. The results indicated that the PVA/SiO2 AMPEs containing 5 ω nano-SiO2 filler exhibited good performances at room temperature, such as 1.62×10-2S·cm-1for ionic conductivity and 2.20 V for electrochemical stability window. What's more, we used the gravimetric method to obtain the electrolyte uptake of various PVA/SiO2 composite micro-porous polymer membranes. From the data, we learned that the maximum electrolyte uptake could reach to 102.7% and it had very relevance to the size of pores in PVA/SiO2 composite polymer membranes, and then influenced the ionic conductivity. Each polymer Ni-MH battery was assembled by three parts: the new AMPE, Mg-based hydrogen storage alloy and the commercial sintered Ni(OH)2/NiOOH electrode, in which each part did for electrolyte and diaphragm, negative electrode and positive electrode, respectively. The cycle experiments of the batteries exhibited a high first-cycle discharge capacity of 613 mAh·g-1 and stable discharge capacities about 330 mAh·g-1 for the following 5 cycles. The results encouraged that the novel AMPEs are prospective for the applications of polymer electrolyte in Ni-MH battery field.

Key words: PVA, alkaline micro-porous polymer electrolyte, ionic conductivity, cycling stability, polymer Ni-MH battery