基于互穿网络技术构筑环境友好型聚合物电解质膜与电化学性能

Construction and electrochemical performances of environment-friendly polymer electrolyte via interpenetrating network technology

摘要:

利用互穿网络技术通过乳液聚合法制备环境友好型聚合物电解质膜,采用FTIR、XPS、SEM、TEM和TG等技术对样品结构和形貌进行表征；通过CV、EIS和充放电测试结果分析样品的电化学性能。结果表明：当m(AMPS):m(BA):m(AA):m(AN)=1:3:2:2时,互穿网络聚合物电解质膜的离子电导率为0.88mS/cm；聚合物膜的抗拉强度为7.53MPa,断裂伸长率为90.4%；聚合物膜的吸液量为150%,热收缩率为4%,表现出最佳的力学性能和电化学性能。该互穿网络聚合物电解质膜与目前锂离子电池主流的正负极材料具有较好的相容性,普适性较好。以LiCoO₂为正极,石墨为负极,0.2C倍率下,首次放电比容量分别为141.3mAh/g和347.1mAh/g,100次循环后容量保持率分别为94.8%和85.0%；2C倍率下,放电比容量为119.8mAh/g和239.0mAh/g。关键词：聚合物电解质膜；互穿网络技术；环境友好；锂离子电池

Abstract:

Environmentally friendly polymer electrolyte membrane was prepared by emulsion polymerization via interpenetrating network technology. The physicochemical property of the prepared polymer membrances were characterized by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), mechanical strength measurements, thermal analysis, electrochemical impedance spectroscopy (EIS) and charge-discharge test. The results showed that the as-prepared polymer membrane M2 exhibited a mechanical strength of 7.53 MPa and elongation of 90.4%, uptake electrolyte 150%, thermal shrinkage 4% with ionic conductivity of 0.98 mS/cm at 25 ℃ when the mass ratio of m(AMPS):m(BA):m(AA):m(AN) was 1:3:2:2, demonstrating the best mechanical and electrochemical properties. The polymer electrolyte membrane has good compatibility and universality with the anode and cathode materials current mainstream used in lithium-ion batteries. The LiCoO₂ as cathode active material had an initial discharge capacity of 141.3 mA.h/g, while the graphite as cathode active material possessed an initial discharge capacity of 347.1 mA.h/g, and their corresponding discharge capacity retention were 94.8% and 85.0% after 100 cycles at 0.1 C rate. The battery delivered a discharge capacity of 119.8 mA.h/g and 239 mA.h/g based on the LiCoO₂ and graphite in the cathode at 2.0 C rate, indicating that the prepared material exhibited excellent electrochemical performances.