Abstract
Non-aqueous redox flow batteries (NARFBs) using earth-abundant materials, such as sodium and sulfur, are promising long-duration energy storage technologies. NARFBs utilize organic solvents, which enable higher operating voltages and potentially higher energy densities compared with their aqueous counterparts. Despite exciting progress throughout the past decade, the lack of low-cost membranes with adequate ionic conductivity and selectivity remains as one of the major bottlenecks of NARFBs. Here, we developed a composite membrane composed of a thin (<25 µm) Na+-Nafion coating on a porous polypropylene scaffold. The composite membrane significantly improves the electrochemical stability of Na+-Nafion against sodium metal, exhibiting stable Na symmetric cell performance for over 2300 h, while Na+-Nafion shorted by 445 h. Additionally, the composite membrane demonstrates a higher room temperature storage modulus than the porous polypropylene scaffold and Na+-Nafion separately while maintaining high Na+ conductivity (0.24 mS/cm at 20 °C). Our method shows that a composite membrane utilizing Na+-Nafion is a promising approach for sodium-based hybrid redox flow batteries.
| Original language | English |
|---|---|
| Article number | 700 |
| Journal | Membranes |
| Volume | 13 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2023 |
Funding
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan, accessed on 1 July 2023). This research is sponsored by the U.S. Department of Energy in the Office of Electricity through the Energy Storage Research Program, managed by Imre Gyuk. Authors would like to acknowledge Jagjit Nanda (SLAC National Accelerator Laboratory) for the fruitful discussions. Authors also express gratitude to Michael Starke, the ORNL program manager, for his support in program organization and coordination. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan.
| Funders | Funder number |
|---|---|
| DOE Public Access Plan | |
| United States Government | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
Keywords
- Nafion
- electrochemical stability
- non-aqueous
- polypropylene
- polysulfide
- redox flow battery