Atomic layer deposition of vanadium oxides for thin-film lithium-ion battery applications

Abstract

Amorphous VO₂ thin films are deposited by atomic layer deposition (ALD) using tetrakis[ethylmethylamino]vanadium (TEMAV) as vanadium precursor and water or ozone as the oxygen source. The crystallisation and oxidation behaviour is investigated for different oxygen partial pressures between ambient air and 3.7 Pa, resulting in phase formation diagrams on SiO₂, TiN and Pt substrates, demonstrating a series of stable vanadium oxide phases in the VO₂–V₂O₅ series. Most of the obtained phases exhibit lithium intercalation behaviour in the 1.5–4.5 V vs. Li⁺/Li potential range, and demonstrate high volumetric capacities in the order of V₂O₅ < VO₂ (B) < V₆O₁₃ < V₃O₇ < V₄O₉, with the latter at more than twice the capacity of the best commercial cathode materials.