Advanced Oxygen‐Vacancy Ce‐Doped MoO3 Ultrathin Nanoflakes Anode Materials Used as Asymmetric Supercapacitors with Ultrahigh Energy Density. Issue 16 (11th March 2022)

• Record Type: Journal Article
• Authors: Xu, Liming; Zhou, Weiqiang; Chao, Shixing; Liang, Yanmei; Zhao, Xueqian; Liu, Congcong; Xu, Jingkun
• Is Part Of: Advanced energy materials. Volume 12:Issue 16(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-11
• Subjects: asymmetric supercapacitors -- Ce‐doping -- energy density -- MoO 3 nanoflakes -- oxygen vacancies; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202200101
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Asymmetric supercapacitors (ASC) meet the high power and energy demand in energy storage devices; however, the low capacitance of the anode materials severely hinders the development of ASCs. MoO3 with its high theoretical capacity is an ideal anode material, but its low electrical conductivity limits the application of capacitive energy storage. Herein, abundant oxygen vacancies Ce‐doped MoO3 (OV‐MoO3 /Ce) ultrathin nanoflakes anode materials with a thickness of 1.51‐2.01 nm are constructed by a simple hydrothermal method. It is found that the nanostructure of MoO3 can be controllably changed from thick nanobelts into ultrathin nanoflakes by adjusting the Ce doping concentration. And Ce doping in the OV‐MoO3 lattice can additionally introduce abundant oxygen vacancies without introducing Ce oxide and other impurities. Benefiting from the synergy of ample oxygen vacancies, high specific surface area, and accelerated ion diffusion and charge mobility, the optimized OV‐MoO3 /Ce electrode achieves a high specific capacitance (1439.0 F g ‐1 at 2 mV s ‐1 and 1446.3 F g ‐1 at 5 A g ‐1 ) and good cycle stability. More impressively, the ASC assembled using optimized OV‐MoO3 /Ce as anode materials can provide an ultrahigh energy density of 150.0 Wh kg ‐1 at a power density of 800 W kg ‐1, and the practical demonstration of the assembled ASC device highlights its great potential for high energy storage. Abstract : Control over the construction and thickness of ultrathin oxygen vacancies Ce‐doped MoO3 (OV‐MoO3 /Ce) nanoflakes is realized. The OV‐MoO3 /Ce exhibits an extremely high specific capacitance of 1446.3 F g −1 at 5 A g −1 . When used as an anode, the assembled asymmetric supercapacitor shows an ultrahigh energy density of 150.0 Wh kg −1 at a power density of 800 W kg −1 .