Iron-based sulfates have emerged as promising cathode materials for potassium-ion batteries due to their low cost,high working potential,and environmentally friendly.However,the relatively large ionic radius and slugg...Iron-based sulfates have emerged as promising cathode materials for potassium-ion batteries due to their low cost,high working potential,and environmentally friendly.However,the relatively large ionic radius and sluggish diffusion coefficient of K-ion pose significant challenges to the electrochemical performance and structural stability of cathode materials in potassium-ion batteries(PIBs).In this work,we successfully synthesis a new iron-based sulfate cathode material,potassium sodium iron sulfate(K1.66Na1.02Fe1.66(SO4)3,KNFS),through an electro-chemical ion exchange method.As a cathode material,it exhibits a reversible specific capacity of 83 mAh·g^(−1) and an average working potential of 3.84 V(vs.K/K^(+))at 0.1 C in PIBs.Even at 2 C,it still demonstrates a reversible specific capacity of 52 mAh·g^(−1) with a capacity retention ratio of 88.2%after 300 cycles.The in-situ X-ray diffraction(XRD)and ex-situ X-ray absorption spectroscopy reveal that the K-ion storage mechanism in KNFS is predominantly governed by the reversible Fe3+/Fe2+redox couple,which provides a theoretical specific capacity of 94 mAh·g^(−1) and involves minimal volume change(2.57%).The first-principles calculations combined with XRD results indicate that the KNFS cathode exhibits a typical alluaudite-type crystal structure with multiple fast K-ion migration channels along the three-dimensional orientation.展开更多
对近年来第一性原理计算在锂离子电池聚阴离子型正极材料研究方面的应用进行了综述。主要包括Li Fe PO4结构与性质的计算研究、其他橄榄石结构正极材料的研究、新型聚阴离子型正极材料的研究等方面。较详细的介绍了它们的研究过程,讨论...对近年来第一性原理计算在锂离子电池聚阴离子型正极材料研究方面的应用进行了综述。主要包括Li Fe PO4结构与性质的计算研究、其他橄榄石结构正极材料的研究、新型聚阴离子型正极材料的研究等方面。较详细的介绍了它们的研究过程,讨论了取得的成果,分析了研究特点。在对上述研究内容进行简要评述的基础上阐述了继续开展的相关研究领域。展开更多
基金funded by the Science and Technology Commission of Shanghai Municipality(No.19D.Z.2271100)the China Postdoctoral Science Foundation(No.2024M750490)The authors would like to express their sincere gratitude to Ms.Li from Scientific Compass(www.shiyanjia.com)for her valuable assistance in XPS testing.
文摘Iron-based sulfates have emerged as promising cathode materials for potassium-ion batteries due to their low cost,high working potential,and environmentally friendly.However,the relatively large ionic radius and sluggish diffusion coefficient of K-ion pose significant challenges to the electrochemical performance and structural stability of cathode materials in potassium-ion batteries(PIBs).In this work,we successfully synthesis a new iron-based sulfate cathode material,potassium sodium iron sulfate(K1.66Na1.02Fe1.66(SO4)3,KNFS),through an electro-chemical ion exchange method.As a cathode material,it exhibits a reversible specific capacity of 83 mAh·g^(−1) and an average working potential of 3.84 V(vs.K/K^(+))at 0.1 C in PIBs.Even at 2 C,it still demonstrates a reversible specific capacity of 52 mAh·g^(−1) with a capacity retention ratio of 88.2%after 300 cycles.The in-situ X-ray diffraction(XRD)and ex-situ X-ray absorption spectroscopy reveal that the K-ion storage mechanism in KNFS is predominantly governed by the reversible Fe3+/Fe2+redox couple,which provides a theoretical specific capacity of 94 mAh·g^(−1) and involves minimal volume change(2.57%).The first-principles calculations combined with XRD results indicate that the KNFS cathode exhibits a typical alluaudite-type crystal structure with multiple fast K-ion migration channels along the three-dimensional orientation.
文摘对近年来第一性原理计算在锂离子电池聚阴离子型正极材料研究方面的应用进行了综述。主要包括Li Fe PO4结构与性质的计算研究、其他橄榄石结构正极材料的研究、新型聚阴离子型正极材料的研究等方面。较详细的介绍了它们的研究过程,讨论了取得的成果,分析了研究特点。在对上述研究内容进行简要评述的基础上阐述了继续开展的相关研究领域。
