Effect of hydrogenation on performance of TiO2(B) nanowire for lithium ion capacitors

Abstract

TiO 2 (B) nanowires have shown excellent capacitance and energy density with a very low charge transfer resistance in 80-μm thick lithium ion capacitor electrodes. Nanowires hydrogenated by heat treatment at 500 °C showed improved Li ions diffusion and an increase in capacitance from 148 to 194 F/g as well as energy density from 23 to 30 Wh/kg. Hydrogenation of oxides as a way to improve their capacitance is critically discussed.

Ultrafast Nanocrystalline‐TiO2(B)/Carbon Nanotube Hyperdispersion Prepared via Combined Ultracentrifugation and Hydrothermal Treatments for Hybrid Supercapacitors

“…The sharpened b ‐axis peak (020) compared to the other as (003) and (60‐1) peaks for the L‐TiO 2 (B) confirms the length of b ‐axis in the TiO 2 (B) (Figure a inset). Cyclic voltammograms for S‐and L‐TiO 2 (B) at 10 mV s −1 (Figure S11, Supporting Information) shows that the shape and the number of the peaks are different between the two samples; the S ‐ TiO 2 (B) shows two sharp peaks at 1.55 and 1.65 V versus Li/Li + , while the L ‐ TiO 2 (B) possesses one broaden peak which is similar to the reported CV shape of TiO 2 (B) nanowire with 20–40 nm of diameter and 1–5 μm length . The sharpening of the peaks for S‐TiO 2 (B) comes from the shortening of b ‐axis length and the increased number of diffusion paths, which enable a fast Li + access and intercalation into TiO 2 (B) A1 and A2 sites along the b ‐axis diffusion channel in the TiO 2 (B) crystals (Figure S11a, Supporting Information), while the L‐TiO 2 (B) shows random Li + intercalation into A1 and A2 sites due to the energy dissipation along the long b ‐axis diffusion paths (Figure S11b, Supporting Information).…”

Electrode Materials, Electrolytes, and Challenges in Nonaqueous Lithium‐Ion Capacitors

“…Some researchers have improved the electrochemical performance of TiO 2 –B by surface modification. Byeon et al synthesized TiO 2 –B nanowires with diameters from 20 to 40 nm and lengths from 1–5 µm. The nanowires were hydrogenated in a heat treatment at 500 °C ( Figure ).…”

“…Schematic presentation of the hydrothermal synthesis and hydrogenation of TiO 2 (B) NWs. Reproduced with permission . Copyright 2015, Elsevier.…”

The 2016 F. M. Becket Summer Research Fellowship — Summary Report: Quinone-Containing Hydrogels as High Performance Pseudocapacitive Electrodes

“…2 Pseudocapacitors store charge through both non-faradic and faradic processes, thereby offering the combined characteristics of EDLCs and batteries. 3,4 and redox-active organic materials, (conducting polymers, carbonyls, viologens, sulfur-containing polymers, etc.). 5,6 The later class of materials are a metal-free, sustainable, flexible, safe and relatively inexpensive choice for pseudocapacitor applications.…”