【作者】 王占良；

【导师】 唐致远；

【作者基本信息】 天津大学 ， 应用化学， 2003， 博士

【摘要】 本文首次合成了聚（甲基丙烯酸甲酯-丙烯腈-甲基丙烯酸锂）(PMAML)新型基质材料，制备了 PVDF-HFP、PMMA 及 PMAML 复合聚合物电解质；提出了新的聚合物电解质制备方法和电池成型方法；探讨了聚合物电解质导电机理和表征方法；研究了聚合物锂离子电池相关的界面性质、快速测试和状态预测方法。本工作主要围绕以下几方面进行： 分别采用抽提法和倒相法制备了 PVDF-HFP 聚合物膜，研究了增塑剂对聚合物电解质及电极材料性能的影响，优化了电池制备工艺。膜的微观结构取决于抽提法中造孔剂和纳米填料含量或倒相法中铸膜液的浓度、溶剂和非溶剂配比。电解液持有量决定膜电导率大小，所制聚合物电解质电导率可达 3.53mS?cm-1，机械强度良好。负极材料的电化学性能强烈依赖于增塑剂组成。 通过交联剂 EGD 对 MMA 进行交联，可以改善 PMMA 基凝胶聚合物电解质机械性能。结果表明该体系最佳组成为 25%MMA，2%EGD，73%电解液，其室温电导率为 2mS?cm-1，电化学窗口为 4.8V。 首次制备了 PMAML/PVDF-HFP 基新型聚合物电解质，并提出了挥发溶剂一步制膜法。调节 PMAML 含量、溶剂挥发速度、环境湿度、铸膜液浓度可控制聚合物膜的孔结构。所制聚合物电解质室温电导率可达 3.7mS?cm-1。PMAML 与PVDF-HFP 比例和 PMAML 组成影响聚合物电解质的电导率、溶剂保持能力和界面性质。 首次提出了一种新的聚合物锂离子电池组装工艺(简称 DC 法)，直接将聚合物材料在电极极片上涂膜，待电池成型后注入电解质溶液活化即可。DC 法工艺简单、易于生产。制得的聚合物锂离子电池电化学性能稳定、大电流放电能力好。 用 IR、XRD 和理论模型分析了聚合物电解质导电机理，并以扩散系数和迁移数表征了其离子传输性质。Peukert 方程和交流阻抗能很好地预测聚合物锂离子电池荷电态，用电流递减放电法能快速测量电池倍率放电性能。 首次通过设计界面，采用交流阻抗技术详细研究了聚合物电解质(GPE)与锂电极、嵌锂电极间界面性质。结果表明：GPE/Li 界面阻抗包括界面钝化层阻抗和电荷传递阻抗，贮存时间、循环伏安、恒流极化等可改变界面阻抗的大小及分布，GPE/嵌锂电极界面阻抗与电极电位有关，锂离子电池阻抗随电压升高而降低。更多还原

【Abstract】 A novel polymer material of Poly(methyl methacrylate-co-acrylonitrile-co-lithium methacrylate)(hereinafter abbreviated to PMAML) was synthesized， andpolymer electrolytes based on PVDF-HFP, PMMA, PVDF-HFP and PMAML blendwere prepared respectively. A new method for preparing polymer electrolyte membraneand a new method for fabricating lithium ion battery with polymer electrolyte wasintroduced respectively. The ion conductive mechanism and characterization methods ofpolymer electrolyte were discussed. The interfacial properties, fast test method andstatus forecast related to lithium ion battery were studied. The main contents of thisthesis as follow: Polymer membranes of PVDF-HFP were prepared by extraction and phaseinversion method respectively, and the affects of organic plasticizer on the performanceof polymer electrolyte and the electrochemical performance of electrode active materialwere investigated, then fabrication art of lithium ion battery with polymer electrolytewere optimized. Content of plasticizer and Inorganic nano powder (in extractionmethod), the content of polymer and non-solvent in the casting liquid (in phaseinversion method) affect pore structure of polymer membrane. The uptake of liquidelectrolyte is critical to conductivity of polymer electrolyte, and the conductivity ofpolymer electrolyte with good mechanical stability can reach 3.53mS?cm-1 at ambienttemperature. The performance of negative material was affected strongly by plasticizers. The mechanical property of polymer electrolyte based on PMMA can be improvedafter PMMA was crosslinked by EGD. The experimental results display that theoptimized component of the polymer electrolyte was 25%MMA，2%EGD，73% liquidelectrolyte. The conductivity and the electrochemical window of the resulted polymerelectrolyte was about 2mS?cm-1 and 4.8V respectively. In this thesis, polymer electrolyte based on the blend of PMAML and PVDF-HFPwas prepared originally, and a novel method for preparing polymer membrane wasintroduced. The pore structure of the polymer membrane can be controlled by changingthe ratio of PMAML to PVDF-HFP, evaporation velocity of solvent, environmentalhumidity and the content of polymer materials in the casting liquid. The conductivity of II <WP=5>the resulted polymer electrolyte was 3.7mS?cm-1. The ratio of PMAML to PVDF-HFPand the composition of PMAML affect ionic conductivity, liquid electrolyte uptake andinterfacial property. A novel method (abbreviated to DC) for assembling lithium ion battery withpolymer electrolyte was introduced originally. In DC method, the polymer material wascoated onto the electrode substrate directly, and lithium ion battery with polymerelectrolyte can be obtained by injecting liquid electrolyte. This process is simple andpractical because the ultra dry environment is unnecessary except the step of liquidelectrolyte injection. Lithium ion batteries with polymer electrolyte based on PMAMLand PVDF-HFP blend display good electrochemical performance and high ratedischarge capability. Ion transport mechanism in polymer electrolyte was analyzed by theoretical model,FT-IR and XRD respectively, and the transport properties were investigated withtransference number and diffusion coefficient. The charge status of lithium ion batterywith polymer electrolyte were forecasted by Peukert equation and AC impedancetechnology. The discharge capability of lithium ion battery with polymer electrolyte atdifferent rate can be tested rapidly by decreasing discharge current consistently. Several kinds of interface were designed, and then interfacial properties betweenpolymer electrolyte and electrode were investigated by AC impedance technologyoriginally. The test results display that interfacial impedance of GPE/Li comprise of twoparts which are interfacial passive layer impedance and charge transfer impedance.Interfacial impedance value更多还原