Ordered mesoporous titanium oxide for thin film microbatteries with enhanced lithium storage

Abstract

A 3D mesoporous TiO 2 material with well-developed mesostructure is prepared in the form of a binderless thin (100 nm) film and studied as potential candidate for the negative electrode in lithium micro-batteries. By appropriate thermal treatments, the selected crystal structure (anatase, rutile, or amorphous), and micro-/mesostructure of the materials was obtained. An extended plateau with at about 0.75 V was found for an X-ray amorphous TiO 2 sample (400 ºC) which can be tentatively assigned to the irreversible formation of cubic Li 2 Ti 2 O 4 . The effects of voltage window and prelithiation treatment improved first cycle reversibility up to 86 % and capacity retention of 90 % over 100 cycles. This study highlights the flexibility of the potential window to which the electrode can operate. Maximum capacity values over 100 cycles of 470 μA h cm 2 μm 1 and 177 μA h cm 2 μm 1 are obtained for voltage ranges of 0.1 2.6 V and 1.0 2.6 V, respectively. The observed values are between 6 and 2 times higher than those obtained for films with 600 nm (80 μAh cm -2 μm -1 ) and 900 nm (92 μAh cm -2 μm -1 ) lengths. This indicates that 100 nm thin TiO 2 films with high accessibility show finite-length type diffusion which is interesting for this particular application.

A Facile Strategy to Construct Silver‐Modified, ZnO‐Incorporated and Carbon‐Coated Silicon/Porous‐Carbon Nanofibers with Enhanced Lithium Storage

“…The electrodes have been prepared according on commercial full battery standard. Before the full‐cell test, the Ag/ZnO‐Si@C‐PCNF electrodes were first prelithiated via direct touch with Li foil under the presence of electrolyte, and then used as anodes for full batteries . Subsequently, the assembled batteries need to undergo a rigorous activation process and then collect their cycling performance as shown in Figure .…”

Mesoporous TiO2 Thin Films: State of the Art

“…However, the preparation of nanostructured TiO 2 in the form of mesoporous thin films could offer some advantages, such as higher specific surface area and thinner walls than a TiO 2 nanotube array [76]. For example, Ortiz et al prepared mesoporous titania thin films on titanium substrates, with a hexagonally ordered porous structure, and they tested these samples as anode materials for LIBs, reporting an improved electrochemical performance, without the necessity of additives to enhance the transport properties of the electrode [77]. The enhanced electrochemical activity was ascribed to the higher area and volumetric capacity of these films due to the presence of the 3D-ordered mesostructure.…”

Polyaniline-Derived N-Doped Ordered Mesoporous Carbon Thin Films: Efficient Catalysts towards Oxygen Reduction Reaction

“…However, in the case of the Titania template, the electrochemical response is lower in G/Ti_PANI_5min_900 than for the pristine G/Ti ( Figure 2 b). Taking into account that the synthesized Titania thin film is mainly formed by anatase phase [ 30 ] and that the transformation of anatase into rutile takes place at around 500 °C [ 37 ], the most likely explanation of the voltammetric behavior is the loss of surface area through the anatase–rutile transformation during the heat treatment at 900 °C, since rutile is known to have a much lower BET surface area than anatase [ 38 ]. This aspect is corroborated in the next section.…”

“…Mesoporous TiO 2 thin films were grown by a route found in the literature, which gives rise to hexagonal thin films [ 29 , 30 ]. In the synthetic protocol, 1.05 g of Pluronic 123 was added to 16.21 g of absolute ethanol.…”

“…The solution was stirred until completely clear, and then 4.03 g of concentrated (37%) HCl was added dropwise. To the resulting mixture, 5.70 g of TTIP was added dropwise, giving the final solution the following molar composition: 1 TTIP: 0.01 P123: 17.6 EtOH: 1.9 HCl: 7.2 H 2 O (that has been previously used to synthesize a hexagonal Titania thin film [ 29 , 30 ]). Titania films were produced by dip-coating at a withdrawal speed of 60 mm·min −1 on the commercial graphite support (1 cm × 1 cm) and using the dip-coating procedure.…”