A single-ion conducting and shear-thinning polymer electrolyte based on ionic liquid-decorated PMMA nanoparticles for lithium-metal batteries

A novel single-ion conducting polymer electrolyte (SIPE) based on ionic liquid (IL)-decorated PMMA nanoparticles dispersed in a propylene carbonate (PC) host is reported. This SIPE possesses a superior lithium-ion transference number (t(Li)(+)) of 0.96 with an enhanced ionic conductivity of 3.13 x 10(-3) S cm(-1) at room temperature and a wide electrochemical window up to similar to 5.18 V. The enhanced ionic conductivity is ascribed to the unique brush-like structure of ionic liquid groups tethered to PMMA nanoparticles. Furthermore, the developed SIPE was found to be more efficient in suppressing lithium dendrite formation on a cycled lithium anode. As little as 11 wt% PMMA-IL-TFSI in a LiTFSI/PC host produces more than a ten-fold increase in the cell lifetime. On the other hand, this SIPE exhibits shear thinning behavior which can be advantageously utilized in electrolyte processing. In addition, galvanostatic cycling measurements in Li/Li4Ti5O12 half cells using this SIPE exhibit excellent rate performance. Even at an extremely high charging rate of 875 mA g(-1) (5C), the capacity is still around 100 mA h g(-1), that is over 57% of the theoretical capacity (175 mA h g(-1)). These attributes enable the developed SIPE to be a promising candidate for high-performance lithium batteries.