ALD Al₂O₃-Coated TiO₂Nanotube Layers as Anodes for Lithium-Ion Batteries

Abstract

The utilization of the anodic TiO2 nanotube layers, with uniform Al2O3 coatings of different thicknesses (prepared by atomic layer deposition, ALD), as the new electrode material for lithium-ion batteries (LIBs), is reported herein. Electrodes with very thin Al2O3 coatings (∼1 nm) show a superior electrochemical performance for use in LIBs compared to that of the uncoated TiO2 nanotube layers. A more than 2 times higher areal capacity is received on these coated TiO2 nanotube layers (∼75 vs 200 μAh/cm2) as well as higher rate capability and coulombic efficiency of the charging and discharging reactions. Reasons for this can be attributed to an increased mechanical stability of the TiO2 nanotube layers upon Al2O3 coating, as well as to an enhanced diffusion of the Li+ ions within the coated nanotube layers. In contrast, thicker ALD Al2O3 coatings result in a blocking of the electrode surface and therefore an areal capacity decrease.

ZnO Coated Anodic 1D TiO2 Nanotube Layers: Efficient Photo‐Electrochemical and Gas Sensing Heterojunction

“…Both images show two distinct tube walls, and the white ZnO layer completely enfolds the tubes. Similarly, homogeneous coatings were achieved within our previous works on Al 2 O 3 coatings for thermal stability and Li‐ion batteries, TiO 2 coatings for photocatalysis, and CdS coatings for solar cells, respectively, within anodic TiO 2 nanotube layers. Figure e and f show the selected area electron diffraction (SAED) and XRD patterns of the ZnO (19 nm) coatings within TiO 2 nanotube layers, respectively.…”

“…The peculiar characteristics are particularly helpful for the deposition of a secondary material in high aspect ratio structures, such as porous anodic alumina, and TiO 2 nanotube layers, as in this study. Very recently, a few works have shown the potential of ALD secondary material in TiO 2 nanostructures . These include ALD ZnO loaded TiO 2 nanowires and nanotubes, both focused on the photocatalytic and photoelectrochemcial (PEC) applications .…”

Niobium Alloying of Self‐Organized TiO2 Nanotubes as an Anode for Lithium‐Ion Microbatteries

“…TiO 2 (anatase or rutile) can accommodate only 0.5 Li + per formula unit, corresponding to a theoretical capacity of 168 mA h g −1 . Hence, several approaches have been investigated to improve the overall performance of TiO 2 ‐NTs for the design of high‐performance Li‐ion microbatteries, including the usage of carbon/graphene nanofibers and surface modification of TiO 2 ‐NTs by Sn and Fe doping, sulfidation, or atomic layer deposition (ALD) of alumina coating . Doping with aliovalent ions is also a facile strategy to modify the electronic properties of titanium oxide and thereby enhance the electrochemical performance.…”

Enhanced Electrochemical Performance of Electropolymerized Self-Organized TiO2 Nanotubes Fabricated by Anodization of Ti Grid

“…However, self-organized TiO 2 nts formed by anodization method is preferred owing to their simplicity, better control over the nanotube morphology and low-cost [19,21]. Thus, pristine as well as chemically modified TiO 2 nts obtained by anodization have been used as negative electrodes for high performance LIBs [22][23][24]. Most studies on self-organized TiO 2 nts are focused on the planar surface, for instance Ti foil.…”