Semi-Interpenetrating Network-Structured Single-Ion Conduction Polymer Electrolyte for Lithium-Ion Batteries

A novel quasi solid single-ion polymer electrolyte with semi-interpenetrating network (semi-IPN) structure has been prepared. The lithium-ion conduction membrane is composed of both the cross-linked lithiated poly-2-acrylamido-2-methylpropane sulfonic acid (PAMPS-Li) as a polyanionic single-ion lithium salt source and the high molecular weight polyethylene oxide (PEO) as a polymer matrix, in which the two components show great compatibility due to the special semi-IPN structure. For such quasi-solid electrolyte system, we have particularly studied the crystallinity variety and ionic conductivity change with a series of polymer salt concentration. The results show that the electrolyte has an appropriate mechanical stability, minimal crystallinity, and acceptable ionic conductivity of 1.34x10(-5) S/cm at 60 degrees C. Furthermore, the lithium-ion conduction membrane shows the lithium-ion dominating conductive property and high transport number of 0.77. Moreover, the LiFePO4/Li batteries' cycle results show a high discharge capacity of 140.0 mAh/g and a retention of 90.4 % after 100 cycles at the rate of 0.2 C.