Electrochemical Energy Storage Applications of CVD Grown Niobium Oxide Thin Films

Abstract

ABSTRACT:We report here on controlled synthesis, characterization and electrochemical properties of different polymorphs of niobium pentoxides grown by CVD of new single-source precursors. Nb2O5 films deposited at different temperatures showed systematic phase evolution from low-temperature tetragonal (TT-Nb2O5, T-Nb2O5) to high temperature monoclinic modifications (HNb2O5). Optimization of the precursor flux and substrate temperature enabled phase-selective growth of Nb2O5 nanorods and films on conductive mesoporous biomorphic carbon matrices (Bio-C). Nb2O5 thin films deposited on monolithic mesoporous biomorphic carbon (Bio-C) scaffolds produced composite materials integrating the high surface area and conductivity of carbonaceous matrix with the intrinsically high capacitance of nanostructured niobium oxide. Hetero-junctions in Nb2O5/BioC composites were found to be beneficial in electrochemical capacitance. Electrochemical characterization of Nb2O5/BioC composites showed that small amounts of Nb2O5 (as low as 5%) in conjunction with Bio-C resulted in a seven-fold increase in the electrode capacitance, from 15 to 104 F g -1 , making these materials ideally suited for electrochemical energy storage applications.

Heteroepitaxial Growth of T-Nb2O5 on SrTiO3

“…Even though polycrystalline T-Nb 2 O 5 films are well studied (see, for example, References [9,10]), epitaxial T-Nb 2 O 5 thin films are not widely available nor studied. Hence, for the full exploitation of their functional properties, the growth of epitaxial T-Nb 2 O 5 is urgently needed.…”

Synthesis and Progress of New Oxygen‐Vacant Electrode Materials for High‐Energy Rechargeable Battery Applications

“…The prepared materials have been widely used as catalysts and energy storage materials because of their unique properties, such as defective structure, high specific surface area, and nanoscale particle size. [64][65][66] Pure-phase LiCoO 2 and LiMg y Co 1−y O 2 (y = 0.1, 0.15) powders were successfully synthesized using a microwave-based synthetic method. [20] Wang et al [30] tried to prepare SnO 2 /graphene composites via a one-step microwave-assisted hydrothermal method (MAHM).…”

“…Therefore, the microwave‐assisted method is a promising method, which can quickly synthesize a large number of materials and have high robustness at high temperature. The prepared materials have been widely used as catalysts and energy storage materials because of their unique properties, such as defective structure, high specific surface area, and nanoscale particle size …”

A cobalt(ii)heteroarylalkenolate precursor for homogeneous Co3O4 coatings by atomic layer deposition

“…The preparation of cobalt oxide by ALD has been previously demonstrated using a wide variety of precursors including oxygen-coordinated compounds: Co(thd) 2 (Hthd=2,2,6,6-tetramethylheptan-3,5-dione)) 11,12 and Co (acac) 3 13 (acac= acetylacetonate), halides as CoI 2 14 and organometallics Co(Cp) 2 (Cp= cyclopentadienyl) [15][16][17][18][19] . Another interesting and evolving family of ALD precursors is the nitrogen-coordinated precursors (alkylamides, silylamides and amidinates, aromatic heterocycles) which have been studied for the deposition of several metals and metal oxides [20][21][22][23][24][25][26][27] but it has been barely explored for the case of Co. [28][29][30] In addition, the air instability of many Co compounds led to increased focus on research of precursors using new ligand systems. [23][24][25][26][27]31 In this work we report on the synthesis and characterization of a novel cobalt precursor Co II (DMOCHCOCF 3 ) 2 3, The cobalt complex Co II (DMOCHCOCF 3 ) 2 was prepared by the reaction of cobalt(II) acetate tetrahydrate with two equivalents of deprotonated ligand 1-(Dimethyl-1,3-oxazol-2-yl)-3,3,3-trifluorprop-1-en-2-ol (DMOCHCOHCF 3 ) in a mixture of tetrahydrofuran (THF) and water, according to the reported procedure.…”

“…Another interesting and evolving family of ALD precursors is the nitrogen-coordinated precursors (alkylamides, silylamides and amidinates, aromatic heterocycles) which have been studied for the deposition of several metals and metal oxides [20][21][22][23][24][25][26][27] but it has been barely explored for the case of Co. [28][29][30] In addition, the air instability of many Co compounds led to increased focus on research of precursors using new ligand systems. [23][24][25][26][27]31 In this work we report on the synthesis and characterization of a novel cobalt precursor Co II (DMOCHCOCF 3 ) 2 3, The cobalt complex Co II (DMOCHCOCF 3 ) 2 was prepared by the reaction of cobalt(II) acetate tetrahydrate with two equivalents of deprotonated ligand 1-(Dimethyl-1,3-oxazol-2-yl)-3,3,3-trifluorprop-1-en-2-ol (DMOCHCOHCF 3 ) in a mixture of tetrahydrofuran (THF) and water, according to the reported procedure. 36 The mixture was stirred for 15 minutes at room temperature and was added dropwise to the solution of Co II (OOCCH 3 ) 2 ·4H 2 O in water.…”