In:
European Journal of Inorganic Chemistry, Wiley, Vol. 2019, No. 39-40 ( 2019-10-31), p. 4365-4372
Abstract:
Co‐containing fluoride‐phosphates are of interest in sense of delivering high electrode potentials and attractive specific energy values as positive electrode materials for rechargeable batteries. In this paper we report on a new Co‐based fluoride‐phosphate, LiNaCoPO 4 F, with a layered structure (2D), which was Rietveld‐refined based on X‐ray powder diffraction data [ P 2 1 / c, a = 6.83881(4) Å, b = 11.23323(5) Å, c = 5.07654(2) Å, β = 90.3517(5) °, V = 389.982(3) Å 3 ] and validated by electron diffraction and high‐resolution scanning transmission electron microscopy. The differential scanning calorimetry measurements revealed that 2D‐LiNaCoPO 4 F forms in a narrow temperature range of 520–530 °C and irreversibly converts to the known 3D‐LiNaCoPO 4 F modification ( Pnma ) above 530 °C. The non‐carbon‐coated 2D‐LiNaCoPO 4 F shows reversible electrochemical activity in Li‐ion cell in the potential range of 3.0–4.9 V vs. Li/Li + with an average potential of ≈ 4.5 V and in Na‐ion cell in the range of 3.0–4.5 V vs. Na/Na + exhibiting a plateau profile centered around 4.2 V, in agreement with the calculated potentials by density functional theory. The energy barriers for both Li + and Na + migration in 2D‐LiNaCoPO 4 F amount to 0.15 eV along the [001] direction rendering 2D‐LiNaCoPO 4 F as a viable electrode material for high‐power Li‐ and Na‐ion rechargeable batteries. The discovery and stabilization of the 2D‐LiNaCoPO 4 F polymorph indicates that temperature influence on the synthesis of A 2 MPO 4 F fluoride‐phosphates needs more careful examination with perspective to unveil new structures.
Type of Medium:
Online Resource
ISSN:
1434-1948
,
1099-0682
DOI:
10.1002/ejic.v2019.39-40
DOI:
10.1002/ejic.201900660
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
1475009-0
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