Gerrard E J Poinern

Current global problems of climate challenges have highlighted the importance of self-sustainable energy production and utilisation. Electricity is an essential energy for everyone in daily life, which powers homes, transportation, activities, jobs and communication. A portable energy storage device becomes an area of interest for researchers in many years, to provide energy for everyone at any time. Among the other rechargeable batteries, the lithium-ion battery (LIB) has been paid much attention due to its high energy density, stable cycling performance and lower self-discharge. To optimise these properties, the electrode material plays an important role as an active material for the electrochemical reaction. In recent years, transition metal oxides have become the most favourable material due to their ease of handling and high capacities (Fang, Bresser and Passerini, 2020). Our research has been focusing on employing iron oxide (α-Fe2O3) nanoparticles as LIB anode. Previous studies show that α-Fe2O3 nanoparticle has a promising capacity by 1187.1 mAh/g (Li et al, 2019), 937 mAh/g (Wu et al, 2019), and 800 mAh/g (Luo et al, 2019). However, the fabrication processes are complicated and not cost-effective for commercial application (Yu et al, 2018) and thus, it remains challenging for the industrial stage. In this research, we utilise an eco-friendly ultrasound-assisted synthesis technique as it is well-known as a facile, low-cost, and eco-friendly technique for nanostructure synthesis (Chatel, 2018; Poinern et al, 2009). We used advanced characterisation including X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) to observe the phase purity, transmission electron microscopy (TEM) to determine the particle size and morphology, thermogravimetric analysis (TGA) to investigate the particle stability at high temperature, and finally cyclic voltammetry (CV) to study the electrochemical performance.

Atomic force microscopy (AFM) was used to characterize poly vinyl alcohol (PVA) stabilized poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles. Highly oriented pyrolytic graphite (HOPG) or Mica was used as substrates for AFM study. The nanoparticulates were imaged in ambient conditions and were observed to be robust during the imaging period. The result shows that AFM can be used as a tool for characterization and optimization of polymeric nanoparticle formulation at the various product development phases to ensure good quality control.