Cross-linked polyaniline for production of long lifespan aqueous iron||organic batteries with electrochromic properties.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37253727.
- Also identified by DOI 10.1038/s41467-023-38890-y and PMC identifier 10229554.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Aqueous iron batteries are appealing candidates for large-scale energy storage due to their safety and low-cost aspects. However, the development of aqueous Fe batteries is hindered by their inadequate long-term cycling stability. Here, we propose the synthesis and application as positive electrode active material of cross-linked polyaniline (C-PANI). We use melamine as the crosslinker to improve the electronical conductivity and electrochemical stability of the C-PANI. Indeed, when the C-PANI is tested in combination with a Fe metal negative electrode and 1 M iron trifluoromethanesulfonate (Fe(TOF)<sub>2</sub>) electrolyte solution, the coin cell can deliver a specific capacity of about 110 mAh g<sup>-1</sup> and an average discharge voltage of 0.55 V after 39,000 cycles at 25 A g<sup>-1</sup> with a test temperature of 28 °C ± 1 °C. Furthermore, mechanistic studies suggest that Fe<sup>2+</sup> ions are bonded to TOF<sup>-</sup> anions to form positively charged complexes Fe(TOF)<sup>+</sup>, which are stored with protons in the C-PANI electrode structures. Finally, we also demonstrate the use of C-PANI in combination with a polymeric hydrogel electrolyte to produce a flexible reflective electrochromic lab-scale iron battery prototype.