Fluorinated polysulfonamide based single ion conducting room temperature applicable gel-type polymer electrolytes for lithium ion batteries

Abstract

Single ion conducting polymer electrolytes (SIPEs) comprised of homopolymers containing a polysulfonylamide segment in the polymer backbone are presented. The polymer structure contains -C(CF 3 ) 2 functional groups that due to better solubility allow for effective lithiation, yielding well-defined materials. An optimized polymer electrolyte membrane was fabricated as a 3:1 blend of single ion conducting polymer and PVdF-HFP, which exhibits a high ionic conductivity of 0.52 mS cm -1 and an impressive lithium ion transference number of 0.9, as well as a 7 Li self-diffusion coefficient of 4.6 × 10 -11 m 2 s -1 at 20 °C. The presented polymer electrolyte has superior oxidative stability and long-term stability against lithium metal, thus facilitating operation in LiNi 1/3 Mn 1/3 CO 1/3 O 2 (NMC111)/lithium metal cells at 20 °C and 60 °C, thereby clearly demonstrating the application potential of this class of materials.