Decoration of indium tin oxide nanoparticles with different crystal structures and morphologies on polypropylene separator for Li-S battery

Indium tin oxide (ITO), an experimentally friendly transparent conducting oxide (TCO), has attracted great attention in the photoelectric field due to its intrinsically low resistivity and high transparency. In this work, the experimental conditions of preparing ITO nanoparticles using the microemulsion method were optimized by an orthogonal experiment. The optimal experimental conditions were obtained: mass ratio of the surfactant (AEO-3, MOA-5), a co-surfactant (n-propyl alcohol) of 5:3, molar ratio of indium and ammonia of 1:20, calcination temperature of 700 °C and calcination time of 4 h. Subsequently, the influence from process variables on the resistivity was researched systematically. The results demonstrated that the calcination temperature had a great effect on the resistivity; the resistivity reduced from 11.28 to 2.72 Ω·cm with the increase in the calcination temperature from 500 to 700 °C. Ultimately, ITO nanoparticles were prepared and systematically characterized under the optimal experimental conditions. The particles with a size of 60 nm were attributed to the cubic ITO crystal phase and showed low resistivity of 0.3675 Ω·cm. Significantly, ITO nanoparticles with low resistivity were obtained using the microemulsion method, which has potential application in the field of ITO nanoparticle preparation.

Optimization Preparation of Indium Tin Oxide Nanoparticles via Microemulsion Method Using Orthogonal Experiment

Indium tin oxide (ITO) is a promising transparent conducting oxide material for photoelectric devices. In this work, the low-resistivity cubic ITO (c-ITO) nanopowders were synthesized via polyacrylamide gel route. The orthogonal experiment design was applied to optimize preparation process that was as follows: n(AM)/n(MBAM) = 25:6, c(In3+) = 0.3 mol/L, calcination temperature (T) = 700 °C, holding time (t) = 9 h. Subsequently, the thermal decomposition process of ITO xerogel, crystal structure, morphology, and electrical conductivity of the optimum sample were characterized systematically. The results indicated that the thermal decomposition of ITO xerogel was a multi-step kinetic reaction process, and the activation energy of reaction depended on the conversion of ITO xerogel. The powders were well indexed to cubic ITO crystal phase, and presented a concentrated particle size distribution of 34–54 nm and nearly spherical-like morphology. The low-resistivity value of 0.161 Ω·cm was obtained under the optimum preparation process. Moreover, the formation mechanism of ITO nanopowders prepared via polyacrylamide gel route was also investigated. The synthesized ITO nanopowders with low resistivity present wide application prospects of next-generation ITO functional materials.

Optimum preparation of low-resistivity indium tin oxide nanopowders via polyacrylamide gel route using orthogonal experiment

Indium tin oxide (ITO) targets are generally prepared with single-size powders. Herein, we proposed a novel strategy to prepare high-quality ITO targets using binary-size particles in different particle count proportions. When the sintering temperature was 1550 ℃ and holding time was 10 h, the target prepared with 118&44 nm powders in particle count proportion of 1:5 showed the maximum relative density of 99.43% and minimum resistivity of 1.41 × 10-4 Ω·cm. We demonstrate that the excellent properties are attributed to the dense microstructure, which is formed by filling the internal gaps among large particles with small particles. 

Yiqing Zhang

Papers

Controllable phase transition ITO nano powders and temperature-structure sensitivity