Investigation of Alkali‐Ion (Li, Na, and K) Intercalation in KxVPO4F (x ∼ 0) Cathode. (20th June 2019)

• Record Type: Journal Article
• Authors: Kim, Haegyeom; Ishado, Yuji; Tian, Yaosen; Ceder, Gerbrand
• Is Part Of: Advanced functional materials. Volume 29:Number 34(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-20
• Subjects: batteries -- cathodes -- lithium -- potassium -- sodium; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201902392
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: This work compares the intercalation of K, Na, and Li in K x VPO4 F ( x ∼ 0). The K x VPO4 F ( x ∼ 0) cathode delivers reversible capacities of ≈90–100 mAh g −1 in K, Na, and Li cells, at an average voltage of ≈4.33 V for K, ≈3.98 V for Na, and ≈3.96 V for Li. This is so far the highest average voltage known for a K‐intercalation cathode. The lower voltage of Li insertion compared to Na is attributable to undercoordinated Li ions in the K x VPO4 F ( x ∼ 0) framework. While the material shows high rate capability for all the alkali ions, Li migration in K x VPO4 F ( x ∼ 0) is more difficult than with Na and K. This work suggests that a large cavity is not always good for insertion of alkali ions and cathode materials need to be suitably tailored to each intercalating ion species. Abstract : This work investigates and compares the K, Na, and Li intercalation properties of the K x VPO4 F ( x ∼ 0) cathode . It demonstrates that large alkali‐ion migration channels are not always good for fast ion diffusion and thus cathode materials need to be suitably tailored to each intercalating ion species.