高分子固体电解质LiNO_3-LiOOCCH_3/聚丙烯酸锂的合成与性能研究

以丙烯酸和氢氧化锂为原料用反相乳液聚合法合成聚丙烯酸锂 (PAALi) ,将其熔于低共熔盐 (一定比例的LiNO3 LiOOCCH3混合物 )中得到新型高分子固体电解质 (SPE) ,用XRD、IR、DTA、TG DTG等技术进行了表征 ,讨论了影响合成PAALi工艺及新型固体电解质电阻率的主要因素 ,在LiNO3 LiOOCCH3摩尔比为 1∶1时 ,将其按质量百分比 80∶2 0与聚丙烯酸锂混合均匀并熔融 ,得到的电解质其室温离子电导率可达 2× 10 - 5S·cm- 1 ,大量低共熔盐的加入可明显提高SPE的离子导电率 .XRD、DTA及TG DTG结果表明低共熔盐与聚丙烯酸锂形成了新的配合物

PREPARATION AND CHARACTERIZATION OF NEW SOLID ELECTROLYTE LiNO3-LiOOCCH3/POLY(LITHIUM ACRYLATE)

The results of preliminary studies of a new polymer electrolytes based on poly(lithium acrylate),PAALi,with low melting point eutectic lithium salts consisted of lithium nitrate and lithium acetate were described.The inverse emulsion polymerization of PAALi was prepared from crylic acid and LiOH under optimum conditions of pH 13,oil/water ratio of 1:1,polymerization time 4?h.The ion conductivity of PAALi was measured at range of 10 -9 ～10 -10 ?S·cm -1 .Thin films of these electrolytes were obtained by coating homogeneous molten mixtures of known masses of host polymer and salt.Electrolytes with compositions of n between 5 and 95,where n represents the mass ratio of the low melting point eutectic lithium salt,have been prepared.These solid polymer electrolytes were characterized by measurements of total ionic conductivity,IR,XRD,differential thermal analysis(DTA)and thermogravimetry(TG).The highest conductivity (approximately 2×10 -5 ?S·cm -1 ) was found at room temperature(30℃) with the electrolyte composition of n equal to 80. XRD,DTA and TG DTG results indicated that a new complex was formed.DTA result show that the melting point of SPE is at 196℃(peak temperature),and the temperature of decompostion is at 273℃.TG DTG reveal that the temperature of SPE is 92℃ lower than that of PAALi,which may be as consequence of interaction between lithium salts and PAALi,weakening the bonds within the macromolecular backbone and making it less resistant to thermal degradation.