Investigation of Novel Polymeric Solid Electrolyte for Lithium Secondary Battery

研究了一种新型的聚合物固体电解质--聚环氧乙烷接枝聚甲基丙烯酸甲酯与锂盐和极性溶剂（碳酸丙烯酯（PC）和/或聚乙二醇（PEG））的聚合物固体电解质.以单体、锂盐、溶剂和光引发剂为原料，通过紫外光照射制备了聚合物固体电解质。所得膜的电导率约为100%。通过<-4><-1><-3><-1>在热处理后将膜浸入液体电解质（锂盐，例如LiClO_4 / PC）中来实现电导率提高至3.5 × 10 - 5S cm-1。研究了锂在聚合物固体电解质中的电极反应。锂电极/聚合物电解质体系中的电荷转移速率较高，在高阴极极化下，离子在本体电解质中的转移速率决定.通过循环伏安法证实了锂离子在聚合物固体电解质中的高级氧化锰电极上的插入和移除。该材料可用作锂二次电池的正极材料。4.根据1 ~ 3的结果，制作了模型锂二次电池。该模型电池具有140 - 200 mAh g^<-1>（每克正极材料）的放电容量和优异的循环性能。

Novel polymeric solid electrolyte, poly (ethylene oxide) -grafted poly (methyl methacrylate) with a lithium salt and polar solvents (propylene carbonate (PC) and/or polyethylene glycol (PEG)) was investigated for lithium secondary batteries.1. The polymeric solid electrolyte was prepared by UV irradiation to mixture of monomer, lithium salt, solvent and photo initiator. Electric conductivity of the resulted film was ca. 10^<-4> S cm^<-1> at room temperature.Improvement of conductivity to 3.5 x 10^<-3> S cm^<-1> was accomplished by dipping the film into a liquid electrolyte (lithium salt, for an example LiClO_4 / PC) after heat treatment.2. The electrode reaction of lithium in the polymeric solid electrolyte was studied. The charge transfer rate at the lithium electrode/polymeric electrolyte was high and the ion transfer in the bulk electrolyte was rate determing at high cathodic polarization.3. Insertion and removal of lithium ions at an advanced manganese oxide electrode in the polymeric solid electrolyte was confirmed by cyclic voltammetry. This material can be used as positive material for a lithium secondary battery.4. According to results from 1 to 3, a model lithium secondary cell was constructed. The model cell had 140 - 200 mAh g^<-1> (per gram of positive material) as discharge capacity and excellent cycle performance.