Construction of phosphorus-doping with spontaneously developed selenium vacancies: Inducing superior ion-diffusion kinetics in hollow Cu_(2)Se@C nanospheres for efficient sodium storage

查看全文 作　　者：Xiaoqing [1,2]Ma;Yadong [3]Li;Xiaojiang [3]Long;Hong-chuan [4,5]Luo;Chunping [3]Xu;Guangzhao [3]Wang;Wenxi [3]Zhao 机构地区：[1]School of Chemistry and Chemical Engineering,Yangtze Normal University,Chongqing 408100,China;[2]Sports Medicine Center,Department of Orthopedic Surgery,Southwest Hospital,the 3rd Military Medical University,Chongqing 400038,China;[3]School of Electronic Information Engineering,Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing,Yangtze Normal University,Chongqing 408100,China;[4]Postgraduate Admission Office of Graduate School,Southwest University,Chongqing 400715,China;[5]Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province,Panzhihua 617000,Sichuan,China 出　　处：《Journal of Energy Chemistry》索引2023年第2期,共13页 基　　金：supported by the China Postdoctoral Science Foundation(Nos.2021M690534 and 2020M673650);the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN202101439 and KJQN202101441);the Innovation Research Team at Institutions of Higher Education in Chongqing(No.CXQT20027);the Program for Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province(No.2022FTSZ02)。 摘　　要：Achieving high-efficiency sodium storage in metal selenides is still severely constrained in consideration of their inferior electronic conductivity and inadequate Na^(+)insertion pathways and active sites.Heteroatom doping accompanied by spontaneously developed lattice defects can effectively tune electronic structure of metal selenides,which give a strong effect to motivate fast charge transfer and Na^(+)accessibility.Herein,we finely designed and successfully constructed a fascinating phosphorus-doped Cu_(2)Se@C hollow nanosphere with abundant vacancy defects(Cu_(2)P_(x)Se_(1-x)@C)through a combination strategy of selenization of Cu_(2)O nanosphere template,self-polymerization of dopamine,and subsequent phosphorization treatment.Such exquisite composite possesses enriched active sites,superior conductivity,and sufficient Na^(+)insertion channel,which enable much faster Na^(+)diffusion rates and more remarkable pseudocapacitive features,Satisfyingly,the Cu_(2)P_(x)Se_(1-x)@C composites manifest the supernormal sodium-storage capabilities,that is,a reversible capacity of 403.7 mA h g^(-1) at 1.0 A g^(-1) over 100 cycles,and an ultrastable cyclic lifespan over 1000 cycles at 20.0 A g^(-1) with a high capacity-retention of about249.7 mA h g^(-1).The phase transformation of the Cu_(2)P_(x)Se_(1-x)@C involving the intercalation of Na^(+)into Cu_(2)Se and the following conversion of NaCuSe to Cu and Na2Se were further demonstrated through a series of ex-situ characterization methods.DFT results demonstrate that the coexistence of phosphorusdoping and vacancy defects within Cu_(2)Se results in the reduction of Na^(+)adsorption energy from-1.47to-1.56 eV improving the conductivity of Cu_(2)Se to further accelerate fast Na^(+)mobility. 关 键 词：Phosphorus-doping Selenium vacancies Hollow Cu_(2)Se@C nanospheres Anode Sodium storage