Poly(ether amine) and cross-linked poly(propylene oxide) diacrylate thin-film polymer electrolyte for 3D-microbatteries

摘要

This paper presents a novel thin-film electrolyte of a 2:1 blend of polyetheramine (glyceryl poly(oxypropylene)) and cross-linked oligomeric poly(propylene oxide) diacrylate with LiTFSI. The polyetheramine acts as a surfactant, and can thereby be applied as a conformal coating on complex surfaces-here demonstrated for porous LiFePO_4 cathodes-making it useful for 3D-microbatteries. The poly(propylene oxide) diacrylate blends with the surfactant and is easily UV cross-linked, thereby ensuring good mechanical stability. Electrolytes, ～ 2 μm thick, were casted onto LiFePO _4 cathodes and cycled against metallic lithium, displaying stable discharge capacities of ～ 8 mAh/g at room temperature and ～ 120 mAh/g at 60 °C. The electrolyte showed conductivities of 3.45 × 10 ~(- 6) and 5.80 × 10~(- 5) S cm~(- 1) at room temperature and 60 °C, respectively.