Uniform yolk-shell iron sulfide-carbon nanospheres for superior sodium-iron sulfide batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 26507613.
- Also identified by DOI 10.1038/ncomms9689 and PMC identifier 4846313.
- 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 sulfide battery holds great promise for sustainable and cost-effective applications. Nevertheless, achieving high capacity and cycling stability remains a great challenge. Here, uniform yolk-shell iron sulfide-carbon nanospheres have been synthesized as cathode materials for the emerging sodium sulfide battery to achieve remarkable capacity of ∼ 545 mA h g(-1) over 100 cycles at 0.2 C (100 mA g(-1)), delivering ultrahigh energy density of ∼ 438 Wh kg(-1). The proven conversion reaction between sodium and iron sulfide results in high capacity but severe volume changes. Nanostructural design, including of nanosized iron sulfide yolks (∼ 170 nm) with porous carbon shells (∼ 30 nm) and extra void space (∼ 20 nm) in between, has been used to achieve excellent cycling performance without sacrificing capacity. This sustainable sodium-iron sulfide battery is a promising candidate for stationary energy storage. Furthermore, this spatially confined sulfuration strategy offers a general method for other yolk-shell metal sulfide-carbon composites.