Ti‐rich TiO₂ Tubular Nanolettuces by Electrochemical Anodization for All‐Solid‐State High‐Rate Supercapacitor Devices

Abstract

Supercapacitors store charge by ion adsorption or fast redox reactions on the surface of porous materials. One of the bottlenecks in this field is the development of biocompatible and high‐rate supercapacitor devices by scalable fabrication processes. Herein, a Ti‐rich anatase TiO2 material that addresses the above‐mentioned challenges is reported. Tubular nanolettuces were fabricated by a cost‐effective and fast anodization process of Ti foil. They attained a large potential window of 2.5 V in a neutral electrolyte owing to the high activation energy for water splitting of the (1 0 1) facet. Aqueous and all‐solid‐state devices showed diffusion time constants of 46 and 1700 ms, as well as high maximum energy (power) densities of 0.844 (0.858) and 0.338 μWh cm−2 (0.925 mW cm−2), respectively. The all‐solid‐state device showed ultrahigh stability of 96 % in capacitance retention after 20 000 galvanostatic charge/discharge cycles. These results open an avenue to fabricate biochemically inert supercapacitor devices.

All-Printed Paper-Based Micro-supercapacitors Using Water-Based Additive-Free Oxidized Single-Walled Carbon Nanotube Pastes

“…Extrusion-based nozzle printing, screen/stencil printing, and inkjet printing techniques are desirable for all-printed MSCs. − Inks and pastes based on metal particles or precursors can be used to print low-sheet resistance current collectors for transistors, diodes, resistors, antennas, and memories. However, in the case of supercapacitors, noble-metal current collectors are required to prevent undesirable electrochemical oxidation and reduction of current collectors . Current collectors printed by silver pastes are highly reactive in acid-based hydrogel electrolytes.…”

Preparation and Characterization of Porous Carbon from Mixed Leaves for High‐Performance Supercapacitors

“…The smaller τ 0 , the relatively higher ionic diffusivity. [ 55 ] Although the τ 0 of PA 3 FP 1 PS 2 AC is not better than those of other AC samples, which implies the low ionic diffusivity, its best conductivity may compensate on it and result in an overall good supercapacitive performance of the sample. More research is needed to further understand the relationship of ionic diffusivity, conductivity, and the supercapacitive performance of the mixed leaves based AC material.…”

The Use of Anodic Oxides in Practical and Sustainable Devices for Energy Conversion and Storage

“…Currently, the use of anodic oxides supercapacitor applications is in the development stage. Due to its high surface area with vertically aligned nanotubes, its chemical and thermal stability, and its wide potential window, the potential of TiO 2 -NT and its composites as electrodes for supercapacitors have been extensively investigated in latest years [31,48,120,[125][126][127][128][129][130][131]. Copper hydroxides/oxides are also receiving attention due to their high theoretical specific capacitance, besides the advantages of the low-cost and abundance of copper [78,124,126,132].…”