Fabrication of Oxygen‐Vacancy Abundant NiMn‐Layered Double Hydroxides for Ultrahigh Capacity Supercapacitors. (22nd January 2020)

• Record Type: Journal Article
• Authors: Tang, Yanqun; Shen, Haoming; Cheng, Jinqian; Liang, Zibin; Qu, Chong; Tabassum, Hassina; Zou, Ruqiang
• Is Part Of: Advanced functional materials. Volume 30:Number 11(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-22
• Subjects: DFT calculation -- energy storage -- layered double hydroxide -- oxygen vacancy -- supercapacitor; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201908223
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The rational design of advanced structures consisting of multiple components with excellent electrochemical capacitive properties is one of the crucial hindrances to be overcome for high‐performance supercapacitors (SCs). Herein, a superfast and facile synthesis of flower‐like NiMn‐layered double hydroxides (NiMn‐LDH) with high SC performance using an electrodeposition process on nickel foam is proposed. Oxygen vacancies are then modulated via mild H2 O2 treatment for the first time, significantly promoting the electrochemical energy storage performance. The oxygen‐vacancy abundant NiMn‐LDH (Ov‐LDH) reaches a maximum specific capacity of 1183 C g −1 at the current density of 1 A g −1 and retains a high capacity retention of 835 C g −1 even at a current density of up to 10 A g −1 . Furthermore, the assembled asymmetric SC device achieves a high specific energy density of 46.7 Wh kg −1 at a power density of 1.7 kW kg −1 . Oxygen vacancies are proven to play a vital role in the improvement of electrochemistry performance of LDH based on experimental and theoretical studies. This vacancy engineering strategy provides a new insight into SC active materials and should be beneficial for the design of the next generation of energy storage devices. Abstract : A rational design of oxygen‐vacancy abundant NiMn‐LDH after morphology regulation and oxygen vacancy optimization contributes to enhanced specific capacity, as well as improved energy density of battery‐type supercapacitors, resulting from the synergistic effect of the hierarchical structure and oxygen vacancies.