Fast-charging 2D phosphate cathodes via green exfoliation: low steric hindrance and efficient Na + transport

The realization of high energy density and fast-charging capability is severely limited by the low intrinsic electronic conductivity and slow ion diffusion rates for the Na 3 V 2 (PO 4 ) 2 O 2 F (NVPOF) cathode in sodium-ion batteries (SIBs). Inspired by the rapid transport of carriers in two-dimens...

Full description

Saved in:
Bibliographic Details
Published in:Green chemistry : an international journal and green chemistry resource : GC 2024-10, Vol.26 (20), p.10538-10548
Main Authors: Wang, Xiao-Tong, Li, Kai, Cao, Jun-Ming, Gu, Zhen-Yi, Zhao, Xin-Xin, Liu, Han-Hao, Guo, Jin-Zhi, Sun, Zhong-Hui, Zheng, Shuo-Hang, Liang, Hao-Jie, Wu, Xing-Long
Format: Article
Language:English
Subjects:
Atomic structure
Bonding strength
Carbonless
Cathodes
Charging
Chemical bonds
Clean energy
Conductivity
Diffusion barriers
Diffusion rate
Electrode materials
Energy gap
Exfoliation
Interlayers
Ion currents
Ion diffusion
Mechanical properties
Sodium
Sodium-ion batteries
Steric hindrance
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The realization of high energy density and fast-charging capability is severely limited by the low intrinsic electronic conductivity and slow ion diffusion rates for the Na 3 V 2 (PO 4 ) 2 O 2 F (NVPOF) cathode in sodium-ion batteries (SIBs). Inspired by the rapid transport of carriers in two-dimensional (2D) frames, we designed a carbonless fast-charging 2D-NVPOF cathode material using H 2 O molecules as the initial green exfoliant for the first time, which achieves the breakage of strong interlayer ionic bonds under mild and safe conditions. After exfoliation operation via mechanical expansion with the assistance of a thermal field, the H 2 O molecules can enter into interlayers of 2D-NVPOF and further coordinate with the defective V atoms, thus enhancing the electronic conductivity, structural robustness and Na + diffusion kinetics, which can be verified from the enhanced (002) lattice plane exposure, reduced band gap and lower Na + migration energy barrier of 2D-NVPOF. In concert, these merits contribute to achieving the excellent fast-charging properties (80% of total battery capacity in 120 s of charging), higher energy density (up to 465 W h kg −1 ), and long-term cycling stability of 2D-NVPOF, highlighting the great potential for practical application in SIBs. This strategy implies that the enhancement of electronic/ionic conductivity in the NASICON structure is achievable without introducing carbon and altering the active center, thus sparking new ideas for improving the fast-charging characteristics of cathodes for SIBs.
ISSN:1463-9262
1463-9270
DOI:10.1039/D4GC03958K