一种新型凝胶改性隔膜在MH-Ni蓄电池中的应用

Study on a novel polymer gel improved separator in nickel/metal hydride battery

研究了一种新型聚合物凝胶改性隔膜在MH-Ni蓄电池中应用的可能性。通过紫外接枝技术,在普通的聚丙烯隔膜两侧接枝了一层聚丙烯酸凝胶膜,当凝胶层吸附碱液后形成凝胶,使这个实验电池体系全固态化。对凝胶改性隔膜进行的电导率及循环伏安测试表明,其作为电解质的性能与KOH水溶液相当;对用凝胶改性隔膜组成的实验电池研究表明,电池的充放电性能及循环寿命均较好,特别是电池的储存性能很好,与相同条件下用KOH水溶液为电解质的实验电池相比,其容量保持率提高了近1倍。同时在整个实验过程中也没有发现凝胶改性隔膜发生降解反应,说明凝胶改性隔膜非常稳定,有可能运用于商业MH-Ni蓄电池。

In this study, we develop a solid polymer membrane gel separator, which comprises a polymerization of acrylic compounds that may also be radiation-grafted onto these separators. In addition, ionic species are added to the solution and remain embedded in the polymer gel after polymerization. The simple experimental Ni-MH cell for a preliminary investigation was assembled using solid polymer membrane gel separator and its charge-discharge characteristics were tested. The results showed that the use of solid polymer membrane gel separator may be a good alternative in order to avoid problems of leakage or electrode corrosion related on the high convection occurring in an aqueous solution of potassium hydroxide. Moreover, the addition of poly (sodium 4-styrenesulfonate) may lead to a decrease of the self-discharge rate. The solid polymer membrane gel separator could be very useful for application in Ni-MH battery.