Engineering the microstructures of manganese dioxide coupled with oxygen vacancies for boosting aqueous ammonium-ion storage in hybrid capacitors

作     者：Xin-Liang Han Jie Zhang Zuo-Shu Wang Hussein A.Younus De-Wei Wang Xin-Liang Han;Jie Zhang;Zuo-Shu Wang;Hussein A.Younus;De-Wei Wang

作者机构：College of Materials Science and EngineeringNorth Minzu UniversityYinchuan 750021China Nanotechnology Research CentreSultan Qaboos UniversityAl-Khoudh123 MuscatOman 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2024年第43卷第11期

页      面：5734-5746页

核心收录：

学科分类：080801[工学-电机与电器] 081704[工学-应用化学] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 

基　　金：financially supported by the National Natural Science Foundation of China(No.22365001) 

主　　题：Ammonium ion hybrid capacitors NH_(4)^(+)storage Oxygen vacancy Manganese oxide Energy storage mechanism 

摘      要：The aqueous ammonium ion(NH_(4)^(+))is a promising charge carrier in virtue of its safety,environmental friendliness,abundant resources and small hydrated ionic *** exploration of NH_(4)^(+)host electrodes with good reversibility and large storage capacity to construct high-performance ammonium-ion hybrid capacitors(AIHCs),however,is still in its ***,a facile etching technique is put forward to produce oxygen-deficient MnO_(2)(O_(d)-MnO_(2))as the electrode material for NH_(4)^(+)*** to the experimental and theoretical calculation results,the etching process not only creates more porosity,offering abundant active sites,but also generates abundant oxygen vacancies,which modify the structure of pristine MnO_(2),enhance charge storage capacity and boost ion diffusion ***,Od-MnO_(2)can deliver a specific capacity of 155 mAh·g^(-1)at 0.5 A·g^(-1)and a good long-term cycling stability with86.8%capacity maintained after 10,000 cycles at5.0 A·g^(-1).Additionally,the NH_(4)^(+)storage mechanism was evidenced by several ex-situ characterization *** examine the actual implementation of O_d-MnO_(2)as a positive electrode for NH_(4)^(+)full device,AIHCs are assembled with activated carbon functionalized with Fe_3O_(4)nanoparticles(Fe_(3)O_(4)@AC)as a negative electrode.A high specific capacitance of 184 F·g^(-1)at 0.5 A·g^(-1),satisfactory energy density of 102 Wh·kg^(-1)at 500 W·kg^(-1),a low self-discharge rate and good cycling durability after 10,000 cycles are *** electrochemical performance of these AIHCs is comparable to or surpass those of traditional supercapacitors with metal ions as charge carriers,highlighting the advantages of structural modification in enhancing the NH_(4)^(+)storage performance.