Jump to main content
Jump to site search

Issue 2, 2018
Previous Article Next Article

A highly ordered multi-layered hydrogenated TiO2-II phase nanowire array negative electrode for 2.4 V aqueous asymmetric supercapacitors with high energy density and long cycle life

Author affiliations

Abstract

To increase the active material loading coupled with the improvement of electrical conductivity and ionic transport in the TiO2 based negative electrode for 2.4 V aqueous asymmetric supercapacitors (ASCs), a highly ordered binder-free multi-layered hydrogenated TiO2-II phase nanowire array (ML-HTO) electrode is synthesized via a multi-step method. Due to the highly ordered scaffold-like multi-layered structure, a hydrogenated TiO2-II phase, small TiO2 grains (4.4 nm), high oxygen vacancy (Ti3+) concentration and functionalized hydrophilic surfaces, endowing the electrode with high electrical conductivity (low band gap of 2.39 eV), more positive flat-band potential (−0.35 V) and a high Na+ diffusion coefficient (3.08 × 10−8 cm2 s−1), the as-prepared ML-HTO electrode with high active material loading (3.0 mg cm−2) exhibits a high areal specific capacitance (710.7 mF cm−2), which is much higher than that of a pristine TiO2 nanowire array (TO) electrode (28.3 mF cm−2) and the single layered hydrogenated TiO2 nanowire array (HTO) electrode (258.7 mF cm−2). Consequently, a 2.4 V aqueous ASC was firstly assembled with the ML-HTO electrode as the negative electrode, presenting a high energy density of 90.3 W h kg−1 at 349.0 W kg−1, as well as a high volumetric energy density of 9.6 mW h cm−3 at 61.0 mW cm−3, which is much higher than most of previously reported aqueous ASCs. The capacitance retention of the as-prepared MnO2//ML-HTO ASC is 65.7% after 10 000 cycles, demonstrating its long cycle life.

Graphical abstract: A highly ordered multi-layered hydrogenated TiO2-II phase nanowire array negative electrode for 2.4 V aqueous asymmetric supercapacitors with high energy density and long cycle life

Back to tab navigation

Supplementary files

Publication details

The article was received on 31 Oct 2017, accepted on 04 Dec 2017 and first published on 04 Dec 2017


Article type: Paper
DOI: 10.1039/C7TA09590B
Citation: J. Mater. Chem. A, 2018,6, 623-632
  •   Request permissions

    A highly ordered multi-layered hydrogenated TiO2-II phase nanowire array negative electrode for 2.4 V aqueous asymmetric supercapacitors with high energy density and long cycle life

    Y. Tang, Y. Li, W. Guo, J. Wang, X. Li, S. Chen, S. Mu, Y. Zhao and F. Gao, J. Mater. Chem. A, 2018, 6, 623
    DOI: 10.1039/C7TA09590B

Search articles by author

Spotlight

Advertisements