Enhanced Electrochemical Performance of Electropolymerized Self-Organized TiO2 Nanotubes Fabricated by Anodization of Ti Grid

Vinsensia Ade Sugiawati,Florence Vacandio,Alina Galeyeva,Andrey P. Kurbatov,Thierry Djenizian

doi:10.3389/fphy.2019.00179

Abstract

Self-organized TiO2 nanotubes grown on Ti grid acting as anode for Li-ion microbatteries were prepared via an electrochemical anodization. By tuning the anodization time, the morphology and length of the nanotubes were investigated by scanning electron microscope. When the anodization time reached 1.5 h, the TiO2nts/Ti grid anode showed a well-defined nanotubes, which are stable, well adherent ~90 nm with a length of 1.88 µm. Due to their high surface utilization, surface area and material loading per unit area, TiO2nts /Ti grid anode using polymer electrolyte exhibited a high areal capacity of 376 µAh cm-2 at C/10 rate and a stable discharge plateau at 1.8 V without using a polymer binder and conductive additive. The storage capacity of the TiO2nts/Ti grid after 10 cycles is fifteen times higher compared to previous reports using planar Ti foils.

Highlights

Due to their high energy density, no memory effect and long cycle life, rechargeable Li-ion batteries (LIBs) have been extensively used as power sources for many electronic devices [1,2,3,4]
The minor increase in current density at the early stage of anodization might be attributed to the exposure of surface area that was not covered with the electrolyte due to the nature of the Ti grid structure
Self-organized TiO2nts starts to form as the result of the competition between electrochemical oxide formation and chemical dissolution of the oxide layer by fluoride ions according to Equations (1) and (2), respectively

Summary

INTRODUCTION

Due to their high energy density, no memory effect and long cycle life, rechargeable Li-ion batteries (LIBs) have been extensively used as power sources for many electronic devices [1,2,3,4]. Liu et al fabricated vertically oriented TiO2 nanotube arrays with controllable lengths on Ti grids by electrochemical anodization in ethylene glycol-based electrolyte and investigated their potential application as flexible electrodes for DSSCs [30]. To improve the performance of the TiO2nts anodes for Li-ion microbatteries, self-organized TiO2nts grown on Ti grid is considered as a great choice owing to its large aspect ratio of length to diameter, higher surface area, and high Ti conversion into TiO2nts [33, 34]. The effect of the anodic oxidation time on the formation of the TiO2nts were investigated by scanning electron microscopy (SEM) and the electrochemical performances of the electropolymerized TiO2nts was studied by cyclic voltammetry and galvanostatic charge/discharge cycling. The cells were galvanostatically charged and discharged in the potential window of 1–3 V vs. Li/Li+ at different current densities and cyclic voltammetry was performed at a scan rate of 0.1 mV s−1 using a VMP3 potentiostat-galvanostat (Bio Logic)

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT