Solid polymer electrolyte comprised of lithium salt/ether functionalized ammonium-based polymeric ionic liquid with bis(fluorosulfonyl)imide

New solid polymer electrolytes (SPEs) comprised of lithium bis(fluorosulfonyl) imide (Li[N(SO2F)2], LiFSI) and polymeric ionic liquid (i.e., poly[N,N-dimethyl-N-[2-(methacryloyloxy) ethyl]-N-[2-(2-methoxyethoxy) ethyl]ammonium] bis(fluorosulfonyl) imide, P[C5O2NMA,11]FSI) have been prepared and characterized. For comparison, the corresponding SPEs, lithium bis(trifluoromethylsulfonyl) imide (Li[N(SO2CF3)2], LiTFSI)/poly[N,N-dimethyl-N-[2-(methacryloyloxy) ethyl]-N-[2-(2-methoxyethoxy) ethyl]ammonium] bis(trifluoromethylsulfonyl) imide (P[C5O2NMA,11]TFSI), are also prepared and characterized. Their physicochemical properties have been investigated in terms of phase transition behavior, ionic conductivity, lithium-ion transference number (tLi+), electrochemical stability, and with particular attention to the interfacial behavior between lithium electrode and SPEs. It has been demonstrated that the ionic conductivities of LiFSI/P[C5O2NMA,11]FSI electrolyte are higher than those of the corresponding TFSI-based one. The interface resistances of Li symmetric cell (Li metal | polymer electrolytes | Li metal) using LiFSI/P[C5O2NMA,11]FSI electrolyte are much lower than those using LiTFSI/P[C5O2NMA,11]TFSI electrolyte. These outstanding properties of the FSI-based electrolyte make it attractive as SPEs for Li battery.