Tunable built-in electric fields enable high-performance one-dimensional co-axial MoOx/MoON heterojunction nanotube arrays for thin-film pseudocapacitive charge storage devices. Issue 22 (28th May 2021)

• Record Type: Journal Article
• Authors: Jin, Bowen; Chen, Peng; Chu, Hongqi; Zhang, Dan; Cui, Shuangshuang; Zhou, Xin; Yang, Min
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 22(2021)
• Page Start: 13263
• Page End: 13270
• Publication Date: 2021-05-28
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta02360h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Two kinds of built-in electric field (BEF) – in opposite directions – are produced at fully charged and discharged states on co-axial MoO x /MoON nanotubes, which increase the transport kinetics of the electrode. Abstract : Battery-type electrode materials show inferior power density due to sluggish ion-diffusion kinetics within the solid phase. Herein, we outline a strategy to improve the cation migration for ultrafast energy storage by utilizing a built-in electric field (BEF) at the heterostructure interface. Both theoretical calculations and Kelvin probe measurements reveal that two kinds of BEF – in opposite directions – are produced at fully charged and discharged states on co-axial MoO x /MoON nanotubes (NTs). The transport kinetics are greatly increased by the BEF effect, leading to a dramatic increase of capacitance, especially at a high charging rate. Subsequently, MoO x /MoON NTs exhibit a specific capacitance of 1976 F cm −3 at a current density of 2.5 A cm −3 . And 1267 F cm −3 is retained at a high current density of 100 A cm −3, which can be ascribed to the improvement of fast ionic transport in the electrode bulk caused by the BEF effect. This work also inspires a new pathway toward rational engineering of heterostructures for high-capacitance and high-rate energy storage.