Carbon-Coated Na3V2(PO4)3 Anchored on Freestanding Graphite Foam for High-Performance Sodium-Ion Cathodes

Xiongwu Zhong; Zhenzhong Yang; Yu Jiang; Weihan Li; Lin Gu; Yan Yu

doi:10.1021/acsami.6b11873

Carbon-Coated Na₃V₂(PO₄)₃ Anchored on Freestanding Graphite Foam for High-Performance Sodium-Ion Cathodes

ACS Appl Mater Interfaces. 2016 Nov 30;8(47):32360-32365. doi: 10.1021/acsami.6b11873. Epub 2016 Nov 15.

Authors

Xiongwu Zhong¹, Zhenzhong Yang², Yu Jiang¹, Weihan Li¹, Lin Gu^{2

3}, Yan Yu^{1

4

5}

Affiliations

¹ Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences (CAS), Department of Materials Science and Engineering, University of Science and Technology of China , Hefei, Anhui 230026, China.
² Beijing Laboratory for Electron Microscopy, Institute of Physics, Chinese Academy of Sciences (CAS) , Beijing, 100190, China.
³ Collaborative Innovation Center of Quantum Matter , Beijing 100190, China.
⁴ Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University , Tianjin 300071, China.
⁵ State Key Laboratory of Fire Science, University of Science and Technology of China , Hefei, Anhui 230026, China.

PMID: 27808497
DOI: 10.1021/acsami.6b11873

Abstract

Na₃V₂(PO₄)₃ (NVP) has been considered as a most promising cathode material for sodium-ion batteries (SIBs), but NVP usually exhibits poor cycling stability and rate performance due to the low intrinsic electrical conductivity. Herein, we prepared carbon-coated Na₃V₂(PO₄)₃ anchored on freestanding graphite foam (denoted as NVP@C-GF) as a cathode for SIBs. The NVP@C-GF exhibits superior sodium-ion storage performance, including rate capability (56 mAh g^-1 at 200 C) and long cycle life (54 mAh g^-1 at 100 C after 20 000 cycles). The resulting NVP@C-GF inherits the advantages of 3D free-standing graphite that possesses high electrical conductivity and porous structure for the electrolyte to soak in. Furthermore, carbon-coated NVP particles anchored on the surface of GF not only accommodate the volume change of NVP during charge/discharge but also reduce the diffusion distance of the Na⁺ ion.

Keywords: Na3V2(PO4)3; cathode; freestanding electrode; graphite foam; sodium-ion battery.