High Lithium Ion Electroinsertion Rate into Self-Assembled Films Formed from TiO₂

Abstract

We prepared self-assembled materials consisting of TiO 2 nanoparticles, N,O-carboxymethylchitosan (NOCMCh), and poly(ethylene oxide) (PEO) by the layer-by-layer (LbL) technique, aiming to employ them as modified electrodes under high lithium ion electroinsertion rate. Electrostatic interaction between the components promoted growth of visually uniform TiO 2 /NOCMCh films with highly controlled thickness. We used NOCMCh to produce a polymeric mixture with PEO to incorporate the polyether into the self-assembled structure during the preparation of the LbL TiO 2 /NOCMCh/PEO films. Scanning electron microscopy (SEM) and contact angle measurements between the electrolytic solution and the thin films surface suggested that the polymers affected the mean size of the aggregates and the permeation of the electrolytic solution into the host matrix, leading to greater electrolytic connection between the TiO 2 sites. Chronopotentiometric curves and the differential capacities recorded as a function of the potential under several applied current densities indicated higher charge capacity and absorbance changes (ΔA) for the TiO 2 /NOCMCh/PEO electrode. We employed the potentiostatic intermittent titration technique (PITT) to determine the chemical diffusion coefficient (D c ) associated with electron and lithium ion diffusion in the host matrices. To investigate the independent motion of these charge carriers in the absence of an internal electrical field, we also obtained the Wagner factor (W) and the lithium (D Li ) and electron (D e ) self-diffusion coefficients. Spectroelectrochemical measurements also indicated higher coloration front rate due to lithium ion transport in the TiO 2 /NOCMCh/PEO electrodes. The electrochemical impedance spectroscopy (EIS) measurements suggested trapping effects and anomalous diffusion, which contributed to a better understanding of the role that polymeric components play in charge transport within the self-assembled materials under high electroinsertion rate.

Encapsulating Mo-Doped TiO2 Anatase in N-Doped Amorphous Carbon With Excellent Lithium Storage Performances

“…To solve its intrinsic disadvantage, different strategies have been devoted to improve the lithium ion storage performance, such as compounding with conductive agents to enhance electronic conductivity (Gomes et al, 2013;Wang et al, 2016), reducing particle size to nano-scale to shorten the lithium ion diffusion distance (Hu et al, 2015), and manufacturing mesoporous or porous TiO 2 to increase the electrolyte/electrode contact area (Li et al, 2015. Furthermore, researchers found that the electrical property of TiO 2 is impressible to aliovalent ions doping in the lattice (Zhang et al, 2012;Zhao et al, 2015).…”

Ion intercalation dynamics of electrosynthesized mesoporous WO3 thin films studied by multi-scale coupled electrogravimetric methods

“…[1][2][3][4] Among these materials, tungsten(VI) oxide (WO 3 ) is a particular metal oxide which can offer a wide range of technological applications. energy storage, electrochromic devices, etc.…”

“…has become a subject of growing interest. [1][2][3][4] Among these materials, tungsten(VI) oxide (WO 3 ) is a particular metal oxide which can offer a wide range of technological applications. It is a representative metal oxide of a group of chromogenic materials due to the coloration effects associated with various processes.…”

Insertion of Magnesium into Antimony Layers on Gold Electrodes:Kinetic Behaviour

“…The rate of insertion, and therefore the diffusion coefficient of metal ions in the electrode material, is one of the important evaluation parameters for fast charging and discharging metal ion battery. For determining diffusion coefficient of Lithium in the solid state electrode materials, electrochemical methods such as Electrochemical Impedance Spectroscopy (EIS), [26,27] Galvanostatic Intermittent Titration Technique (GITT), [26,28] Potentiostatic Intermittent Titration Technique (PITT) [29–33] and Cyclic Voltammetry (CV) [34,35] have been applied.…”