van Laack Vanessa, Langer Frederieke, Hartwig Andreas, Koschek Katharina
Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359Bremen, Germany.
Department of Biology/Chemistry, University of Bremen, Leobener Straße 3, 28359Bremen, Germany.
ACS Omega. 2023 Mar 2;8(10):9058-9066. doi: 10.1021/acsomega.2c02174. eCollection 2023 Mar 14.
A plastic crystalline electrolyte (PCE) consisting of 0.4 mol/L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in succinonitrile (SN) was blended with poly(ethylene oxide) (PEO), poly(vinylpyrrolidone) (PVP), poly(ethylene carbonate) (PEC), and polyacrylonitrile (PAN). The influences of the regarding polymers on thermomechanical properties of the PCE were studied systematically, utilizing differential scanning calorimetry, thermogravimetric analysis, and oscillation experiments. Depending on the chosen polymer, the melting temperature and overall crystallinity of the PCE were increased. For PCEs containing PEO and PVP, overall crystallinity was enhanced the most resulting in lamellae-like superstructures, identified by light microscopy images. Furthermore, the onset for the sublimation process of SN was shifted to higher temperatures, and the mechanical strength was increased by the presence of some polymers, with exception of PEC. Electrochemical characterization, including electrochemical impedance spectroscopy and linear sweep voltammetry, revealed ionic conductivities of 10 S/cm at room temperature for PCE with PAN and extended electrochemical stability windows of ≥4.5 V vs lithiated graphite for PCE with PEO. By correlating the thermomechanical and electrochemical properties, some structure-property relationships were drawn, pointing out great potential for specific tailoring of PCEs by polymer additives. The synergistic effect of increasing both, mechanical stability and ionic conductivity, made the PCE + PAN composition especially attractive for a possible application in batteries.
一种由0.4 mol/L双（三氟甲烷磺酰）亚胺锂（LiTFSI）溶解于丁二腈（SN）中构成的塑性晶体电解质（PCE），与聚环氧乙烷（PEO）、聚乙烯吡咯烷酮（PVP）、聚碳酸亚乙酯（PEC）和聚丙烯腈（PAN）进行了共混。利用差示扫描量热法、热重分析和振荡实验，系统研究了上述聚合物对PCE热机械性能的影响。根据所选聚合物的不同，PCE的熔点和整体结晶度有所提高。对于含有PEO和PVP的PCE，整体结晶度提高最为显著，形成了片状超结构，这在光学显微镜图像中得到了确认。此外，SN升华过程的起始温度向更高温度偏移，并且某些聚合物（PEC除外）的存在提高了机械强度。包括电化学阻抗谱和线性扫描伏安法在内的电化学表征显示，含PAN的PCE在室温下的离子电导率为10 S/cm，含PEO的PCE相对于锂化石墨的电化学稳定窗口扩展至≥4.5 V。通过关联热机械性能和电化学性能，得出了一些结构-性能关系，指出了通过聚合物添加剂对PCE进行特定定制的巨大潜力。机械稳定性和离子电导率均提高的协同效应，使得PCE + PAN组合物对于电池的可能应用特别具有吸引力。
