Extended Data Fig. 8: FMN-Na|K4Fe(CN)6 Battery performance.
From: Hydrophilic microporous membranes for selective ion separation and flow-battery energy storage
a, Typical charging-discharging curves, and b, capacity and efficiency of RFBs using Nafion 212 membrane at current densities varied from 20 to 100 mA cm−2. c, Cycling performance for Nafion 212 membranes over 300 cycles at 80 mA cm2. d, Typical charging-discharging curves, and e, capacity and efficiency of RFBs using TB-based membranes at current densities varied from 20 to 100 mA cm−2. f, Cycling performance of RFBs using PIM-EA-TB TFC and PIM-BzMA-TB TFC membranes over 300 cycles at 80 mA cm−2. With a low area-specific resistance, PIM-EA-TB TFC membrane enables the operation of FMN-Na|K4Fe(CN)6 flow battery at high current of 80 mA cm−2 with a current efficiency of 96.1% and a discharge capacity of 2.52 A h l−1 (utilization ratio of 96.7 % in terms of the theoretical capacity). After 300 cycles, batteries using PIM-EA-TB TFC and PIM-BzMA-TB TFC membranes exhibited similar and remarkably high capacity retentions of 86.5% and 86.1% respectively. g, Capacity and efficiency at current densities varied from 20 to 100 mA cm−2 and h, cycling performance at 80 mA cm−2 for battery system using AO-PIMs membranes. The capacity retention of AO-PIM-1 over 300 cycles is 84.5 %, comparable to the performance of Nafion 212. i, Cycling performance for AO-PIM-SBF at 80 mA cm−2. AO-PIM-SBF membrane also proved the feasibility of membrane design strategy. Electrolytes: 10 ml 0.06 M FMN-Na and 10 ml 0.1 M K4Fe(CN)6 in 1.0 M NaOH solution. The batteries were operated in an open-air atmosphere.
