ALD grown WS2 films are recommended to use as intercalation material in Li-ion battery because of its excellent electrochemical stability.

This article demonstrates the atomic layer deposition (ALD) of tungsten nitride using tungsten hexacarbonyl [W(CO)6] and ammonia [NH3] and its use as a lithium-ion battery anode. In situ quartz crystal microbalance (QCM), ellipsometry and X-ray reflectivity (XRR) measurements are carried out to confirm the self-limiting behaviour of the deposition. A saturated growth rate of ca. 0.35 Å per ALD cycle is found within a narrow temperature window of 180-195 °C. In situ Fourier transform infrared (FTIR) vibrational spectroscopy is used to determine the reaction pathways of the surface bound species after each ALD half cycle. The elemental presence and chemical composition is determined by XPS. The as-deposited material is found to be amorphous and crystallized to h-W2N upon annealing at an elevated temperature under an ammonia atmosphere. The as-deposited materials are found to be n-type, conducting with an average carrier concentration of ca. 10(20) at room temperature. Electrochemical studies of the as-deposited films open up the possibility of this material to be used as an anode material in Li-ion batteries. The incorporation of MWCNTs as a scaffold layer further enhances the electrochemical storage capacity of the ALD grown tungsten nitride (WNx). Ex situ XRD analysis confirms the conversion based reaction mechanism of the as-grown material with Li under operation.

Mitigating photocorrosion in the light absorber material used for photoelectrochemical solar water splitting is a subject of major research. In this work, a systematic investigation is carried out on suppressing the photocorrosion in an electrodeposited Cu2O photocathode using stable protective layers. The photocathode protected with chemical vapor deposited graphene offers significant stability, till 600 s during light chopping chronoamperometry. However, the presence of a few microcracks in the graphene layer cannot offer complete protection, and causes a gradual decay in the photocurrent. The addition of an ultrathin layer (≈10 nm) of amorphous TiO2 on top of the graphene blocks the microcracks, thereby resulting in complete protection to the Cu2O absorber layer. The TiO2/graphene protected Cu2O photocathode generates ‐3 mA cm−2 photocurrent at 0.0 V versus reversible hydrogen electrode under 1 sun in 1 m Na2SO4 electrolyte (pH 7), which is twice that compared to the bare Cu2O electrode. The enhancement in photocurrent can be attributed to the ease of separating the photogenerated charge carriers due to the suitable band alignment and electron selective nature of the protective TiO2/graphene layers.

LIBs that provided an understanding of how ITO works in LIBs. There are three main ways ITO materials have been exploited-i) As an electrode protecting layer: [5] ITO coated on LiMn 2 O 4 (LMO) showed enhancement in the electrochemical performance when compared to pristine LMO. It is believed that the conductive ITO layer can reduce cell polarization, interparticle resistance, and charge-transfer resistance between LMO particles and the electrolyte solution. Furthermore, the ITO layer could suppress Mn dissolution as well. ii) As a current collector: [6] The electronic conductivity of ITO makes it comparable to the commonly used current collector such as Cu, Pt, and TiN. Additionally, oxidation, a major issue for TiN and Cu current collectors, does not occur in ITO as the ions involved are already in the highest oxidation state (In 3+ and Sn 4+). This makes ITO a promising candidate to serve as a current collector especially suitable for potentially high temperature conditions. iii) As an anode: [7] In 2 O 3 and SnO 2 are electrochemically active toward lithium at the potential range of 0-3 V (vs Li + /Li) with high theoretical capacities (In 2 O 3 578 mAh g −1 , SnO 2 782 mAh g −1). Based on this background, it is believed that ITO can also be exploited as a potential anode material for LIBs. Several deposition techniques are reported to obtain ITO thin-films including spray pyrolysis, [8] sol-gel methods, [9] pulsed laser deposition, [10] e-beam evaporation, [11] physical vapor deposition, [12] chemical vapor deposition, [13] and atomic layer deposition (ALD). [14] Among these methods, ALD is a thin-film deposition technique that is based on alternating, self-limiting chemical reactions between gaseous precursors and a solid surface to produce high quality, uniform and conformal coatings even at low growth temperatures. [15] The ALD method enables precise control over the thickness, composition, and structure (such as intermixed or laminated structure) of the films and allows for conformal coatings to be applied on all exposed complex surfaces, such as 3D silicon micropillars, [16] 3D anodic aluminum oxide, [17] aerogel, [18] and mesoporous membranes. [19] The preparation of ITO thinfilms via the ALD method was reported in several previous This work demonstrates the possible usages of indium tin oxide (ITO) thin-films as multifunctional coatings on V 2 O 5 model electrodes for lithium-ion batteries (LIBs). The thin films are produced with the atomic layer deposition (ALD) method via adjusting the ratio of In 2 O 3 and SnO 2 sub-layers to a well-controlled In: Sn contents. The highest conductivity value (7.37 × 10 −4 Ω cm) of as-grown ITO film is obtained from the sample containing 5% SnO 2 of overall ALD cycles. The ITO thin-films are further investigated as multifunctional coatings on ALD V 2 O 5 electrodes for LIBs: At first, dual electronic and ionic conductive protecting properties of ITO layer are explored to attenuate the fading of the battery capacity by improving the cycling stability. Second, the feasi...

Due to its high theoretical capacity, energy density and excellent reversibility with Li/Li + , molybdenum oxides are one of the vastly studied electrode material in lithium-ion batteries. However, like most of the oxides, it also suffers from poor cyclic stability because of their low electrical conductivity. In 3-D core shell structure prepared by atomic layer deposition coating can provide superiority in nanoscale decoration than other deposition methods because of its extreme conformality and precise thickness control on high aspect ratio surfaces. This report illustrates the electrochemical activity of 3-D coreshell type amorphous MoO x material coated by atomic layer deposition technique on conducting carbon nanotubes (CNT) scaffold which exhibits excellent overall cell capacity. The obtained capacity is manifold higher than its planer 2-D counterpart and that can become an advanced nanoscale fabrication methodology of such 3-D nanostructures for electrode preparation. Such binder free MoO x /CNT core-shell electrode structure shows very high and stable electrochemical activity towards Li/Li + system. An optimal thickness of MoO x on CNT is also found out in order to attain the most stable cyclic performance of this nanostructure. A stable reversible areal capacity of 645 µAh cm -2 with specific capacity of 915 mAh g -1 is achieved from optimized MoO x /CNT assembly.Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff))