Enhanced conductivity and stability of Prussian blue cathodes in sodium-ion batteries by surface vapor-phase molecular selfassembly  

作　　者：Tao Yuan Xiaopan Fu Yuan Wang Mingjie Li Shuixin Xia Yuepeng Pang Shiyou Zheng 

机构地区：[1]School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China

出　　处：《Nano Research》2024年第5期4221-4230,共10页纳米研究（英文版）

基　　金：support of the National Natural Science Foundation of China(Nos.22379096,52271222,51971146,51971147,52171218,52371230);support of Shanghai Outstanding Academic Leaders Plan,the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00015);Shanghai Pujiang Program(No.21PJ1411100);Shanghai Rising-Star Program(Nos.20QA1407100,21QA1406500);the Shanghai Science and Technology Commission(Nos.21010503100,20ZR1438400,22ZR1443900).

摘　　要：With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical applications still suffer from a low actual specific capacity and inferior stability owing to the imperfect crystallinity,irreversible phase transition,and low intrinsic conductivity.Herein,a surface-modification technique for vapor-phase molecular self-assembly was developed to prepare Fe-based PBAs,specifically sodium iron hexacyanoferrate(NaFeHCF),with a uniform conductive polymer protective layer of polypyrrole(PPy)on the surface,resulting in [e-mail] incorporation of a PPy protective layer not only improves the electronic conductivity of NaFeHCF@PPy,but also effectively mitigates the dissolution of Fe-ions during cycling.Specifically,this advanced vapor-phase technique avoids Fe^(2+)oxidation and Na^(+)loss during liquid-phase surface modification.The NaFeHCF@PPy exhibited a remarkably enhanced cycling performance,with capacity retentions of 85.6%and 69.1%over 500 and 1000 cycles,respectively,at 200 mA/g,along with a superior rate performance up to 5 A/g(fast kinetics).Additionally,by adopting this strategy for Mn-based PBAs(NaMnHCF@PPy),we further demonstrated the universality of this method for PBA cathodes in SIBs.

关 键 词：sodium-ion battery CATHODE Prussian blue analogs surface modification vapor-phase molecular self-assembly 

分 类 号：O64[理学—物理化学]