Nareerat Plylahan

Highly conformal electrodeposition of copolymer electrolytes into titania nanotubes for 3D Li-ion batteries

The highly conformal electrodeposition of a copolymer electrolyte (PMMA-PEO) into self-organized titania nanotubes (TiO2nt) is reported. The morphological analysis carried out by scanning electron microscopy and transmission electron microscopy evidenced the formation of a 3D nanostructure consisting of a copolymer-embedded TiO2nt. The thickness of the copolymer layer can be accurately controlled by monitoring the electropolymerization parameters. X-ray photoelectron spectroscopy measurements confirmed that bis(trifluoromethanesulfone)imide salt was successfully incorporated into the copolymer electrolyte during the deposition process. These results are crucial to fabricate a 3D Li-ion power source at the micrometer scale using TiO2nt as the negative electrode.

Enhanced electrochemical performance of Lithium-ion batteries by conformal coating of polymer electrolyte

This work reports the conformal coating of poly(poly(ethylene glycol) methyl ether methacrylate) (P(MePEGMA)) polymer electrolyte on highly organized titania nanotubes (TiO2nts) fabricated by electrochemical anodization of Ti foil. The conformal coating was achieved by electropolymerization using cyclic voltammetry technique. The characterization of the polymer electrolyte by proton nuclear magnetic resonance (1H NMR) and size-exclusion chromatography (SEC) shows the formation of short polymer chains, mainly trimers. X-ray photoelectron spectroscopy (XPS) results confirm the presence of the polymer and LiTFSI salt. The galvanostatic tests at 1C show that the performance of the half cell against metallic Li foil is improved by 33% when TiO2nts are conformally coated with the polymer electrolyte.

Mechanism study of Li+ insertion into titania nanotubes

Li+ insertion into anatase titania nanotubes (TiO2nts) employing PEO-based polymer electrolyte has been studied by cyclic voltammetry and chronoamperometry. The study shows that Li+ storage in the anatase is dominated by the bulk diffusion (into the lattice) and the increasing contribution of the pseudo-capacitive effect with faster kinetics. We also report that the chemical diffusion of Li+ in self-organized TiO2nts is around 2 × 10−16 cm2 s−1 suggesting that the use of a solid electrolyte does not alter the charge transport in the nanostructured electrode.