Controllable Synthesis of TiO2@Fe2O3 Core-Shell Nanotube Arrays with Double-Wall Coating as Superb Lithium-Ion Battery Anodes

Abstract

Highlighted by the safe operation and stable performances, titanium oxides (TiO2) are deemed as promising candidates for next generation lithium-ion batteries (LIBs). However, the pervasively low capacity is casting shadow on desirable electrochemical behaviors and obscuring their practical applications. In this work, we reported a unique template-assisted and two-step atomic layer deposition (ALD) method to achieve TiO2@Fe2O3 core-shell nanotube arrays with hollow interior and double-wall coating. The as-prepared architecture combines both merits of the high specific capacity of Fe2O3 and structural stability of TiO2 backbone. Owing to the nanotubular structural advantages integrating facile strain relaxation as well as rapid ion and electron transport, the TiO2@Fe2O3 nanotube arrays with a high mass loading of Fe2O3 attained desirable capacity of ~520 mA h g−1, exhibiting both good rate capability under uprated current density of 10 A g−1 and especially enhanced cycle stability (~450 mA h g−1 after 600 cycles), outclassing most reported TiO2@metal oxide composites. The results not only provide a new avenue for hybrid core-shell nanotube formation, but also offer an insight for rational design of advanced electrode materials for LIBs.

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

“…24−26 However, although several reports can be found on utilization of the ALD coatings of different materials to modify the electrodes for lithium-ion battery application, 27−33 only one publication reports on the use of ALD to coat an anode prepared from an anodic TiO 2 nanotube layer with ZnO. 23 …”

Recent advances in hierarchical anode designs of TiO2‐B nanostructures for lithium‐ion batteries

“…Recent progress has been recorded in exploring new heterological hybrid designs, for instance, core-shell, and yolk-shell among TiO 2 -B nanowires and metal oxides (SnO 2 , anatase TiO 2 , Fe 2 O 3 ) (Figure 5). 60,[120][121][122][123][124][125] The effective combination of the two active materials in one smart morphological electrode system has promised to provide excellent cycle and rate performances at the same time. In this regard, both Zhang and Yang reported that when SnO 2 NPs or SnO 2 nanocrystals were uniformly coated on the entire surface of TiO 2 -B nanowire backbones, they formed novel core-shell designs as advanced anode materials in LIBs.…”

“…This also created a large exposure area between the anode materials and electrolyte, facilitating the insertion/extraction of Li +. 110,122,128 More importantly, these hybrid nanostructures could largely alleviate the agglomerations for the SnO 2 NPs and also for the TiO 2 -B nanostructures. As a result, the reversible capacity reached about 1160 mAh g À1 at C/5 rate and an excellent capacity cyclability achieved 790 mAh g À1 after 30 cycles.…”

Heterogeneous nanostructure array for electrochemical energy conversion and storage

“…This was 80% of the initial capacity comparing with 30% retention in the case of bare Si NWs under the same cycling conditions. Chao et al coated a mesoporous thin layer of PEDOT on the V2O5 nanobelt arrays (Figure 10d,10e) directly grown on the 3D ultrathin graphite foam (UGF) [145]. The thin layer can not only facilitate the electron transfer around V2O5 but also decrease the polarization and improve the reaction kinetics.…”