Lithium Iron Phosphate Nanowire Synthesis using Aluminum Oxide Templates

  • Maarten Geest

Student thesis: Master's Thesis

Abstract

Over the past decades, lithium-ion batteries (LIBs) based on lithium cobalt oxide (LiCoO2) have transformed the way we live and communicate. They are the main power suppliers in laptops, cell-phones and other consumer products that require a small, portable power source. In recent years, rising prices, safety issues and environmental concerns related to LiCoO2 and cobalt extraction have spurred a search for alternatives. Lithium iron phosphate (LiFePO4) was proposed as an alternative cathode material in 1997, being potentially cheaper, safer and also more environmentally benign than LiCoO2. Characterization of this material brought up two main problems, that have to be solved before LiFePO4 can be used as a cathode material for LIBs: (I) slow lithium intercalation kinetics and (II) low conductivity. Solving these problems could lead to cheaper and more environmental friendly LIBs, that therefore also have potential for large-scale energy storage, electric grid stabilization and (hybrid) electric vehicles. Three methods are known to help solve the conductivity and kinetics problems associated with LiFePO4: decreasing particle size; doping particles with supervalent atoms and applying a thin carbon coating. In this work, LiFePO4 nanomaterials are synthesized using sol-gel with precipitation methods and compared, with the ultimate aim of synthesizing LiFePO4 nanowires for the purpose of studying their properties and possible applications. It is shown that sol-gel and precipitation methods can be used to synthesize LiFePO4 nano-materials with favorable properties, using anodized aluminum oxides with cylindrical pores of 200 nm in diameter as a template material. Suggestions for future research are done at the end of the work.
Date of AwardAug 2015
Original languageAmerican English
SupervisorDaniel Choi (Supervisor)

Keywords

  • Aluminum Oxide
  • Lithium Iron Phosphate
  • LiFePO4
  • Gol-Gel
  • Nanomaterials
  • Nanowires.

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