Development of High-Performance Iron-Based Phosphate Cathodes toward Practical Na-Ion Batteries

Chunliu Xu; Lin Zhou; Teng Gao; Zhao Chen; Xueyan Hou; Jiao Zhang; Ying Bai; Liangrong Yang; Huizhou Liu; Chao Yang; Junmei Zhao; Yong-Sheng Hu

doi:10.1021/jacs.3c14452

Development of High-Performance Iron-Based Phosphate Cathodes toward Practical Na-Ion Batteries

J Am Chem Soc. 2024 Apr 10;146(14):9819-9827. doi: 10.1021/jacs.3c14452. Epub 2024 Mar 28.

Authors

Chunliu Xu^{1

2}, Lin Zhou², Teng Gao², Zhao Chen², Xueyan Hou², Jiao Zhang², Ying Bai³, Liangrong Yang^{1

4}, Huizhou Liu^{1

4}, Chao Yang^{1

4}, Junmei Zhao^{1

4}, Yong-Sheng Hu²

Affiliations

¹ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
² Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
³ International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004, P. R. China.
⁴ School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 38546207
DOI: 10.1021/jacs.3c14452

Abstract

Iron-based phosphate cathode of Na₄Fe₃(PO₄)₂(P₂O₇) has been regarded as a low-cost and structurally stable cathode material for Na-ion batteries (NIBs). However, their practical application is greatly hindered by the insufficient electrochemical performance and limited energy density. Here, we report a new iron-based phosphate cathode of Na_4.5Fe_3.5(PO₄)_2.5(P₂O₇) with the intergrown heterostructure of the maricite-type NaFePO₄ and orthorhombic Na₄Fe₃(PO₄)₂(P₂O₇) phases at a mole ratio of 0.5:1. Benefited from the increased composition ratio and the spontaneous activation of the maricite-type NaFePO₄ phase, the as-prepared Na_4.5Fe_3.5(PO₄)_2.5(P₂O₇) composites deliver a reversible capacity over 130 mA h g^-1 and energy density close to 400 W h kg^-1, which is far beyond that of the single-phase Na₄Fe₃(PO₄)₂(P₂O₇) cathode (∼120 mA h g^-1 and ∼350 W h kg^-1). Moreover, the kg-level products from the scale-up synthesis demonstrate a stable cycling performance over 2000 times at 3 C in pouch cells. We believe that our findings could show the way forward the practical application of the iron-based phosphate cathodes for NIBs.