Potassium Prussian Blue Nanoparticles: A Low-Cost Cathode Material for Potassium-Ion Batteries

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• 作者：Chenglin Zhang ; Yang Xu ; Min Zhou ; Liying Liang ; Huishuang Dong ; Minghong Wu ; Yi Yang and Yong Lei
• 刊名：Advanced Functional Materials
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：27
• 期：4
• 全文大小：1985K
• ISSN：1616-3028

文摘

Potassium-ion batteries (KIBs) in organic electrolytes hold great promise as an electrochemical energy storage technology owing to the abundance of potassium, close redox potential to lithium, and similar electrochemistry with lithium system. Although carbon materials have been studied as KIB anodes, investigations on KIB cathodes have been scarcely reported. A comprehensive study on potassium Prussian blue K_0.220Fe[Fe(CN)₆]_0.805⋅4.01H₂O nanoparticles as a potential cathode material is for the first time reported. The cathode exhibits a high discharge voltage of 3.1–3.4 V, a high reversible capacity of 73.2 mAh g⁻¹, and great cyclability at both low and high rates with a very small capacity decay rate of ≈0.09% per cycle. Electrochemical reaction mechanism analysis identifies the carbon-coordinated Fe^III/Fe^II couple as redox-active site and proves structural stability of the cathode during charge/discharge. Furthermore, for the first time, a KIB full-cell is presented by coupling the nanoparticles with commercial carbon materials. The full-cell delivers a capacity of 68.5 mAh g⁻¹ at 100 mA g⁻¹ and retains 93.4% of the capacity after 50 cycles. Considering the low cost and material sustainability as well as the great electrochemical performances, this work may pave the way toward more studies on KIB cathodes and trigger future attention on rechargeable KIBs.