Lithiated Prussian blue analogues as positive electrode active materials for stable non-aqueous lithium-ion batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36526618.
- Also identified by DOI 10.1038/s41467-022-35376-1 and PMC identifier 9758126.
- 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
Prussian blue analogues (PBAs) are appealing active materials for post-lithium electrochemical energy storage. However, PBAs are not generally suitable for non-aqueous Li-ion storage due to their instability upon prolonged cycling. Herein, we assess the feasibility of PBAs with various lithium content for non-aqueous Li-ion storage. We determine the crystal structure of the lithiated PBAs via neutron powder diffraction measurements and investigate the influence of water on structural stability and Li-ion migration through operando X-ray diffraction measurements and bond valence simulations. Furthermore, we demonstrate that a positive electrode containing Li<sub>2-x</sub>FeFe(CN)<sub>6</sub>⋅nH<sub>2</sub>O (0 ≤ x ≤ 2) active material coupled with a Li metal electrode and a LiPF<sub>6</sub>-containing organic-based electrolyte in coin cell configuration delivers an initial discharge capacity of 142 mAh g<sup>-1</sup> at 19 mA g<sup>-1</sup> and a discharge capacity retention of 80.7% after 1000 cycles at 1.9 A g<sup>-1</sup>. By replacing the lithium metal with a graphite-based negative electrode, we also report a coin cell capable of cycling for more than 370 cycles at 190 mA g<sup>-1</sup> with a stable discharge capacity of about 105 mAh g<sup>-1</sup> and a discharge capacity retention of 98% at 25 °C.