中国科学院过程所赵君梅团队报道了用于实用钠离子电池的高性能磷酸铁基阴极的研制。相关研究成果于2024年3月28日发表在国际顶尖学术期刊《美国化学会杂志》。

Na₄Fe₃₍PO₄)₂(P₂O₇)铁基磷酸盐阴极被认为是一种低成本且结构稳定的钠离子电池（NIBs）阴极材料。然而，由于电化学性能不足和能量密度有限，它们的实际应用受到很大阻碍。

该文中，研究人员报道了一种新的铁基磷酸盐阴极Na_4.5Fe_3.5(PO₄)_2.5(P₂O₇)，其具有水镁石型NaFePO₄和正交Na₄Fe₃₍PO₄)₂(P₂O₇)相的共生异质结构，摩尔比为0.5:1。得益于水镁石型NaFePO₄相的组成比增加和自发活化，所制备的Na_4.5Fe_3.5(PO₄)_2.5(P₂O₇)复合材料的可逆容量超过130 mA h g^–1，能量密度接近400 W h kg^–1，远远超过单相Na₄Fe₃₍PO₄)₂(P₂O₇)。此外，来自放大合成的公斤级产品在袋状电池中，在3摄氏度下表现出超过2000次的稳定循环性能。

该发现可以为铁基磷酸盐阴极在NIBs中的实际应用指明方向。

附：英文原文

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

Author: 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

Issue&Volume: March 28, 2024

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 Na4.5Fe3.5(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 Na4.5Fe3.5(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.

DOI: 10.1021/jacs.3c14452

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.3c14452