Two-electron redox chemistry enables potassium-free copper hexacyanoferrate as high-capacity cathode for aqueous Mg-ion battery  

作　　者：Ying Ling Bing He Lijie Han Wenbin Gong Chaofeng Chang Qichong Zhang 

机构地区：[1]Key Laboratory of Multifunctional Nanomaterials and Smart Systems,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou,the People's Republic of China [2]School of Electrical and Electronic Engineering,Nanyang Technological University,Singapore,Singapore [3]School of Physics and Energy,Xuzhou University of Technology,Xuzhou,the People's Republic of China [4]Sustainable Energy Laboratory,Faculty of Materials Science and Chemistry,China University of Geosciences Wuhan,Wuhan,the People's Republic of China

出　　处：《InfoMat》2024年第6期64-75,共12页信息材料（英文）

基　　金：National Key R&D Program of China,Grant/Award Number:2022YFA1203304;Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20220288;Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Grant/Award Number:E1552102。

摘　　要：Prussian blue analogs(PBAs)are potential contestants for aqueous Mg-ion batteries(AMIBs)on account of their high discharge voltage and threedimensional open frameworks.However,the low capacity arising from single reaction site severely restricts PBAs'practical applications in highenergy-density AMIBs.Here,an organic acid co-coordination combined with etching method is reported to fabricate defect-rich potassium-free copper hexacyanoferrate with structural water on carbon nanotube fiber(DCuHCF@CNTF).Benefiting from the high-valence-state reactive sites,arrayed structure and defect effect,the well-designed D-CuHCF@CNTF exhibits an extraordinary reversible capacity of 146.6 mAh g1 with two-electron reaction,nearly close to its theoretical capacity.It is interesting to unlock the reaction mechanism of the Fe2+/Fe3+and Cu+/Cu2+redox couples via x-ray photoelectron spectroscopy.Furthermore,density functional theory calculations reveal that Fe and Cu in potassium-free D-CuHCF participate in charge transfer during the Mg2+insertion/extraction process.As a proof-of-concept demonstration,a rocking-chair fiber-shaped AMIBs was constructed via coupling with the NaTi2(PO4)3/CNTF anode,achieving high energy density and impressive mechanical flexibility.This work provides new possibilities to develop potassium-free PBAs with dual-active sites as high-capacity cathodes for wearable AMIBs.

关 键 词：aqueous Mg-ion battery energy-storage fiber high capacity Prussian blue analogs twoelectron reaction 

分 类 号：TM912[电气工程—电力电子与电力传动]