Biomass mediated multi layered NaNixCo1−xO2 (x = 0.4) and α-Fe2O3 nanoparticles for aqueous sodium ion battery

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2020-02, Vol.858, p.113809, Article 113809
• Main Authors: Nwanya, Assumpta Chinwe, Ndipingwi, Miranda M., Ikpo, Chinwe O., Ezema, Fabian I., Iwuoha, Emmanuel I., Maaza, Malik
• Format: Article
• Language: English
• Subjects: Activated carbon; Bio-synthesis; Capacity; Chemical synthesis; Current density; Discharge; Electrodes; Electron microscopes; Energy storage; Hematite; Iron oxides; NaNixCo1−xO2; Nanoparticles; Silk; Sodium ion battery; Sodium-ion batteries; Zea mays L; α-Fe2O3
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2019.113809

We synthesized NaNixCo1−xO2 and α-Fe2O3 using aqueous extract of Zea mays L. dry silk extract. Structural characterizations by X-ray diffraction (XRD) and higher resolution transmission electron microscope (HRTEM) show that the NaNixCo1−xO2 can be indexed to the monoclinic space group P2/c with P3 packing phase while that of the iron oxide is consistent with hematite phase of α-Fe2O3 (ICDD card no: 00–033-0664). The scanning electron microscope (SEM) image of the NaNixCo1−xO2 nanoparticles (NPs) reveals an interspersion of rod-like NPs with hexagonal-like and cube-like NPs with uneven dimensions. TEM images of the α-Fe2O3 NPs revealed agglomerated NPs with spherical and quasi spherical shapes of different sizes. The electrochemical energy storage capabilities of the NPs were studied individually as well as a full device using the NaNixCo1−xO2 and the α-FeO2O3 as the positive and negative electrodes respectively. A charge and discharge capacity of about 62 and 25 C g−1 respectively were obatined at a current density of 50 mA g−1 for the full device. However, when we used activated carbon (AC) as the negative and NaNixCo1−xO2 as the positive electrode, we obtained charge and discharge capacities of 378 C g−1 (105 mAh g−1) and 283 C g−1 (79 mAh g−1) respectively at a current density of 80 mA g−1. Therefore, the bio-synthesized NaNixCo1−xO2 NPs is a potential material for application in electrochemical storage devices. [Display omitted] •Multi layered NaNixCo1-xO2 (x =0.4) and α-Fe2O3 NPs were synthesized using aqueous extract from by Zea mays L, dry silk.•A device developed using NaNixCo1-xO2 and α-Fe2O3 NPs as positive and negative electrode respectively gave discharge capacity of about 25 C g-1.•However, when AC is used as the negative electrode, discharge capacity of 283 mA g-1.