Banca de QUALIFICAÇÃO: MARIA NICHEILLY PONTES ARAÚJO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA NICHEILLY PONTES ARAÚJO
DATE: 24/04/2023
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

Carbon nanotubes applied to lead-acid energy storage systems.

KEY WORDS:

Lead-acid battery. Negative electrode. Carbon nanotubes. Lignosulfonate.

PAGES: 108
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Lead-acid batteries are part of energy storage systems as a vigorous technology, due to cost-benefit, safety and recyclability. However, factors such as low power and specific energy, has been limiting in several applications. Particularly, the new existing demands for energy storage devices, such as in hybrid/electric vehicles and energy storage systems in batteries, has encouraged studies and research, in order to improve aspects such as: increasing the energy density of the system, lifespan, energy efficiency and load acceptance capacity. Considering that the raw materials used in the production of battery electrode materials have considerable influence on the final properties of the material, the objective of this study was to improve the distribution of carbon nanotubes in the mass and to evaluate the final performance of the negative electrode. Thus, dispersion was carried out, with the aid of ultrasound, of different concentrations of carbon nanotubes in water containing lignosulphonate as a dispersing agent. The results obtained in the FTIR, TGA, XRD, SEM and RAMAN analyses, were efficient to prove the functionalization of the nanotube, even more, it was possible to verify that the adsorption of the lignosulphonate molecule occurred on the surface of the nanotube generating a repulsion between the solid particles of NTC in aqueous solution, which generated dispersions with good colloidal stability, proven in the Zeta Potential analysis. The prepared dispersions were also directly applied in the production of prototypes for performance analysis. In the analysis of the micrographs obtained from the cured plates, the dispersion efficiency was verified in the best distribution of the nanotubes in the plate. This better distribution, despite not having influenced an improvement in the load receiving capacity, was able to contribute to the increase in the use of negative active material and promote water consumption within acceptable limits for the application. And, still in comparison with samples of a dispersion already commercialized, the dispersions prepared in this work, presented better load acceptance, acceptable water consumption and better yield of the active material, which are evidences that the investigations carried out so far show an alternative material for the proposed application.

COMMITTEE MEMBERS:
Externo à Instituição - GILBERTO AUGUSTO DE OLIVEIRA BRITO - UFU
Presidente - 1301548 - MARCELO NAVARRO
Externo à Instituição - ROGERIO TAVARES RIBEIRO - UFPE