The effect of pH on the interlayer distances of elongated titanate nanotubes and their use as a Li-ion battery anode

Abstract

Titanate nanotubes are promising materials for Li-ion battery anodes because of their special morphology and high specific surface areas. These titanates provide high rate capability and low volume expansion upon lithiation. More importantly, their tubular structure helps the transport of ions through the crystal. In this study, we synthesized elongated titanate nanotubes and modified their interlayer distances by changing the pH (2-13). For the structural characterization XRD, BET, SEM and TEM techniques were used. In addition, the effect of interlayer distance on energy capacity and rate capability was investigated. The highest interlayer distance was obtained at pH 10 and with decreasing pH, the interlayer distance dropped until reaching a pH value of 4. Conversely, the specific surface area reached its maximum value of 204 m(2) g(-1) at a pH of 4. Different from anatase (TiO2), titanate nanotubes had broad peaks in cyclic voltammograms suggesting a pseudocapacitive behavior. The sloping profiles of potential-capacity results also supported the pseudocapacitive property. For the titanate nanotubes obtained at pH 10, an initial discharge capacity of 980 mAh g(-1) was achieved. More importantly, titanate nanotubes showed exceptional rate capabilities and the capacities stayed almost constant at high current rates because of their elongated structure. It was found that the interlayer distance and the elongated structure play an important role in the electrochemical performance of the material.

Complete Hydrodesulfurization of Dibenzothiophene via Direct Desulfurization Pathway over Mesoporous TiO2-Supported NiMo Catalyst Incorporated with Potassium

“…The surface area of TiO 2 is increased initially and decreased afterwards with the increasing potassium content. An excessively low pH value of ion exchange may partially dissolve the titanate framework, which is adverse to the achievement of a porous structure of TiO 2 [46]. Our previous work has demonstrated the optimal pH value of ion exchange is 2~4 for constructing mesoporous TiO 2 [47,48].…”

Electrospun Nanotubular Titania and Polymeric Interfaces for High Energy Density Li-Ion Electrodes

“… 18 Thereby acid washing, alkali ions were substituted with hydronium ions through accurate pH adjustments to obtain elongated TNTs. 19 , 20 Further heat treatment aims to take out the existing water molecules in the structure and reach expanded pathways for Li + diffusion. 21 Based on the heat treatment temperature, various structures such as TNT, anatase, TiO 2 -B, or a combination of these can be obtained.…”

Titania-Based Freestanding Electronically Conductive Electrospun Anodes with Enhanced Performance for Li-Ion Batteries

“…As a renowned candidate for energy-related materials, titania-based materials have been utilized in a variety of applications such as solar cells, fuel cells, and LIBs. − Unique properties like decent capacity retention, structural stability, negligible volume change, and promising cyclic behavior make the titanium-based anodes one of the popular study cases among researchers in the field of LIBs. For its certain crystal phases, the theoretical capacity can reach 335 mA h/g, where the crystal structure can make room for one lithium within every TiO 2 unit. , On the other hand, with big particle sizes, the electrode can experience resistance for ionic and electronic conduction.…”