Xu Chunliu, Zhou Lin, Gao Teng, Chen Zhao, Hou Xueyan, Zhang Jiao, Bai Ying, Yang Liangrong, Liu Huizhou, Yang Chao, Zhao Junmei, Hu Yong-Sheng
CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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.
J Am Chem Soc. 2024 Apr 10;146(14):9819-9827. doi: 10.1021/jacs.3c14452. Epub 2024 Mar 28.
Iron-based phosphate cathode of NaFe(PO)(PO) 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 NaFe(PO)(PO) with the intergrown heterostructure of the maricite-type NaFePO and orthorhombic NaFe(PO)(PO) phases at a mole ratio of 0.5:1. Benefited from the increased composition ratio and the spontaneous activation of the maricite-type NaFePO phase, the as-prepared NaFe(PO)(PO) composites deliver a reversible capacity over 130 mA h g and energy density close to 400 W h kg, which is far beyond that of the single-phase NaFe(PO)(PO) cathode (∼120 mA h g and ∼350 W h kg). 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.
NaFe(PO)(PO)的铁基磷酸盐阴极被认为是一种用于钠离子电池（NIBs）的低成本且结构稳定的阴极材料。然而，其电化学性能不足和能量密度有限极大地阻碍了它们的实际应用。在此，我们报道了一种新型的NaFe(PO)(PO)铁基磷酸盐阴极，其具有镁铁矿型NaFePO和正交晶系NaFe(PO)(PO)相以0.5:1的摩尔比共生的异质结构。受益于组成比的增加和镁铁矿型NaFePO相的自发活化，所制备的NaFe(PO)(PO)复合材料具有超过130 mA h g的可逆容量和接近400 W h kg的能量密度，这远远超过单相NaFe(PO)(PO)阴极（约120 mA h g和约350 W h kg）。此外，放大合成的千克级产品在软包电池中于3 C下表现出超过2000次的稳定循环性能。我们相信我们的发现可以为铁基磷酸盐阴极在NIBs中的实际应用指明方向。
