Single Ion Conducting Blend Polymer Electrolytes Based on LiPAAOB and PPEGMA

Abstract

Single-ion polymer electrolytes are expected to play an important role in the development of next-generation lithium batteries. The current work focuses on the designing of novel solid single-ion conducting inorganic polymer electrolytes based on lithium polyacrylic acid oxalate borate (LiPAAOB) and poly(ethyleneglycol) methacrylate (PEGMA). PEGMA is polymerized into PPEGMA via free radical polymerization and LiPAAOB is prepared from poly(acrylic acid), oxalic acid and boric acid. Blend polymer electrolytes were produced by mixing of LiPAAOB with PPEGMA at different weight fractions to enhance the single ion conductivity of the system. To exploit the flexible chemistry and increase segmental mobility of the blend electrolyte, the composition was changed up to 80% with respect to PPEGMA. FT-IR and differential scanning calorimeter technique verifies the interaction between the host and guest polymers. Thermogravimetry analysis verified that the thermal stability of the blends increased up to approximately 200 °C. Scanning electron microscopy images confirm the homogeneity of the blend electrolytes. Cyclic voltammetry studies showed that electrochemical stability electrochemical stability window is approximately 5 V versus Li/Li+. The effect of PPEGMA on to the Lithium ion conductivity was investigated using dielectric impedance analyzer. The maximum single ion conductivity was measured as 1.3 × 10−4 S/cm at 100 °C for the sample LiPAAOB-80PPEGMA. Clearly these results confirmed the positive effect to the increment in ionic conductivity of the blend electrolytes with the addition of PPEGMA.