Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4767784 | Electrochimica Acta | 2016 | 41 Pages |
Abstract
A series of semi-fluorinated sulfonated polyimides (6F-SPIs) are designed and synthesized via a one-step high-temperature polycondensation reaction. The sulfonation degrees of 6F-SPIs are controlled through changing the ratio of sulfonated diamine to non-sulfonated diamine in the casting solution. The physico-chemical properties and single cell performance of 6F-SPI membranes are thoroughly evaluated and compared to a non-fluorinated SPI membrane (6H-SPI-50) and a Nafion 115 membrane. The results show that the designed 6F-SPI membrane with a 50% sulfonation degree (6F-SPI-50) possesses the highest proton selectivity (1.613 Ã 105 S min cmâ3) among all tested membranes. Besides, the 6F-SPI-50 membrane exhibits a promising performance for vanadium redox flow batteries (VRFBs), showing higher coulombic efficiencies (96.90-99.20%) and energy efficiencies (88.25-64.80%) than the Nafion 115 membrane (with coulombic efficiencies of 90.60-96.70% and energy efficiencies of 81.04-60.10%) at the current densities ranging from 20 to 100 mA cmâ2. Moreover, the 6F-SPI-50 membrane shows excellent chemical stability in the VRFB system. This work paves the way for the development of a new class of 6F-SPI membranes for the VRFB application.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Jinchao Li, Suqin Liu, Zhen He, Zhi Zhou,