Zn-doping Effects of Na-rich Na3+xV2-xZnx(PO4)3/C cathodes for Na-Ion Batteries: Lattice distortion induced by doping site and enhanced electrochemical performance

Xinran Li; Cheng Chen; Jian Yang; Zixuan Fang; Shumao Zeng; Tingting Feng; Haiping Zhou; Shu Zhang; Mengqiang Wu

doi:10.1016/j.jcis.2021.12.123

Zn-doping Effects of Na-rich Na_3+xV_2-xZn_x(PO₄)₃/C cathodes for Na-Ion Batteries: Lattice distortion induced by doping site and enhanced electrochemical performance

J Colloid Interface Sci. 2022 Jun 15:616:246-252. doi: 10.1016/j.jcis.2021.12.123. Epub 2021 Dec 23.

Authors

Xinran Li¹, Cheng Chen¹, Jian Yang¹, Zixuan Fang², Shumao Zeng¹, Tingting Feng², Haiping Zhou², Shu Zhang², Mengqiang Wu³

Affiliations

¹ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China.
² School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China; Yangtze Delta Region Institute (HuZhou), University of Electronic Science and Technology of China, Huzhou, Zhejiang 313001, China.
³ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China; Yangtze Delta Region Institute (HuZhou), University of Electronic Science and Technology of China, Huzhou, Zhejiang 313001, China. Electronic address: mwu@uestc.edu.cn.

PMID: 35203037
DOI: 10.1016/j.jcis.2021.12.123

Abstract

To tackle the intrinsic inferior conductivity of the sodium ion batteries (SIBs) cathode Na₃V₂(PO₄)_3, transitional metal cation doping, and carbon frame design are employed for NASICON structural modification. Herein, a hard carbon skeleton Na_3+xV_2-xZn_x(PO₄)₃ NASICON structure is proposed resorting to the combination of flimsy hard carbon slices coating and Zn²⁺ doping along with the introduction of spare Na⁺. The structural distortion caused by the insertion of Zn²⁺ and Na⁺ broadens the transfer channels and increases diffusion routes for Na⁺. At the same time, the anchoring effect for Na_3+xV_2-xZn_x(PO₄)₃ nanoparticles brought by external hard carbon layers and pillar effect aroused by Zn²⁺ provide a stable and firm skeleton, which is conducive to structural stability and reversibility at high current density. Among various doping concentrations, Na_3.03V_1.97Zn_0.03(PO₄)₃ performs a significantly enhanced rate performance with a reversible capacity up to 60 mAh·g^-1 (40C) and ultra-long cycle life of 1000 cycles with a capacity retention of 92.6% at 5C.

Keywords: Sodium-ion battery；Na-rich cathode; Vanadium phosphate sodium; Zn-doping Effects.