A single-phased ringed pyrazolium imide and its potential application for plastic crystal-lithium batteries

摘要

A new member of the plastic crystal, pyrazolium imide family N,N'-pentamethylene pyrazolium bis-(trifluoromethanesulfonyl)imide Pyr7, was prepared. It showed a single, plastic crystalline phase that extends from 47 C to its melting at 75 C. The high conductivity of its neat (1.8x10(-4) S.cm(-1) at T-1/2 = 61 degrees C) and 10 molar% LiTFSI-doped compound (7.9x10(-4) at T-1/2= 55.5 degrees C) along with the wide electrochemical window of Pyr7 (similar to 4.3 V) encouraged us to employ the doped-compound in a lithium-ion battery and good performance was obtained. For the first time, we introduced the sigma T-1/2 term, which should provide a good tool for the comparison of conductivity values for different compounds at the middle of their plastic crystal range.