Electrochemical behaviour of magnesium hydride-added titania anode for Li-ion battery

• Autor(a) principal: Loureiro, Francisco J.A.
• Data de Publicação: 2021
• Outros Autores: PukazhSelvan, D., Bdikin, Igor, Shaula, Aliaksandr L., Mikhalev, Sergey M., Fagg, Duncan P.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/37108
• topic: Lithium ion battery (LIB); Titanium oxide (TiO2); Magnesium hydride (MgH2); Electrochemical Impedance spectroscopy (EIS); Cyclic voltammetry (CV)

This work explores the electrochemical performance of a 10 wt.% MgH2 added titania anode for Li-ion half-cell batteries. We used a distribution function of relaxation times (DFRT) analysis to quantify the sources of polarisation losses from the impedance data. We observed a notable increase in both ohmic and polarisation resistance terms for the TiO2+10 wt.% MgH2 compared to the standard titania anode. Nonetheless, the modified electrode showed a significantly higher lithium diffusion coefficient than pure TiO2, with capacity retention reaching 300 mA h g−1 at 0.1C. Scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) reveals a higher surface coverage by secondary surface(s) upon lithium insertion for MgH2 added titania. Scanning Electron Microscopy (SEM) and atomic force microscopy (AFM) studies provide indirect evidence that different nanodomains with different conducting properties evolve at the anode side upon making various charging/discharging cycles.