Synthesis and characterization of germanium nanowires as active elements in battery electrodes

• Grant number: 22/06259-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2022
• End date: July 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Riama Coelho Gouveia
• Grantee: Rafael Olegario de Sousa
• Host Institution: Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP). Campus Sertãozinho. Sertãozinho , SP, Brazil

Abstract

The need for energy autonomy, as the fabrication of hybrid vehicles, stimulates research for battery optimization. A very common type of battery is lithium-ion, and a promising alternative to increase charge capacity and energy density, as well as prolong cycling, is the replacement of the traditional graphite anode coating with semiconductor nanowire networks, especially Germanium. The carrying capacity of Germanium is more than four times greater than that of graphite and the diffusion of Lithium in Germanium is 400 times greater than in Silicon, in addition to higher conductivity. The use of nanowire networks, in turn, increases the load capacity and ensures greater stability in the volume variation of the lithiation-deletion process, allowing more cycles. For the nanowire network to promote the expected benefits, it is necessary that they establish ohmic contacts, which offer low resistance to charge transport and are resistant to volume variation for many cycles. In this context, the objective of this research project is the synthesis of networks of germanium nanowires by the vapor-liquid-solid method in larger than usual areas and on different surfaces, especially those used as current collectors in lithium-ion batteries, as well as the study of the properties that favor its application in battery electrodes: resistance, electronic transport, storage capacity, cycling. It is expected, as a result, the systematic and reproducible growth of networks of germanium nanowires with high crystallinity, directly in the anode current collectors of lithium-ion batteries, promoting low-resistance and stable contacts, in addition to great charging capacity. and high cycleability in batteries.(AU)