Achieving stable Na metal cycling via polydopamine/multilayer graphene coating of a polypropylene separator.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34599165.
- Also identified by DOI 10.1038/s41467-021-26032-1 and PMC identifier 8486844.
- 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
Sodium metal batteries are considered one of the most promising low-cost high-energy-density electrochemical energy storage systems. However, the growth of unfavourable Na metal deposition and the limited cell cycle life hamper the application of this battery system at a large scale. Here, we propose the use of polypropylene separator coated with a composite material comprising polydopamine and multilayer graphene to tackle these issues. The oxygen- and nitrogen- containing moieties as well as the nano- and meso- porous network of the coating allow cycling of Na metal electrodes in symmetric cell configuration for over 2000 h with a stable 4 mV overpotential at 1 mA cm-2. When tested in full Na || Na3V2(PO4)3 coin cell, the coated separator enables the delivery of a stable capacity of about 100 mAh g-1 for 500 cycles (90% capacity retention) at a specific current of 235 mA g-1 and satisfactory rate capability performances (i.e., 75 mAh g-1 at 3.5 A g-1).