Self-Organized TiO₂/CoO Nanotubes as Potential Anode Materials for Lithium Ion Batteries

Abstract

Electrode material characteristics need to be improved urgently to fulfill the requirements for high performance lithium ion batteries. Herein, we report the use of the two-phase alloy Ti 80 Co 20 for the growth of Ti-Co-O nanotubes (NT) employing an anodic oxidation process in a formamide-based electrolyte containing NH 4 F. The surface morphology and the current density for the initial nanotube formation are found to be dependent on the crystal structure of the alloy phases. XPS analyses of the grown nanotube arrays along with the oxidation state of the involved elements confirmed the formation of TiO 2 /CoO nanotubes under the selected process conditions.The electrochemical performance of the grown nanotubes was evaluated against a Li/Li + electrode at different current densities of 10 -400 µA cm -2 . The results revealed that TiO 2 /CoO nanotubes prepared at 60 V exhibited the highest areal capacity of ~ 600 µAh cm -2 (i.e. 315 mAh g -1 ) at a current density of 10 µA cm -2 . At higher current densities TiO 2 /CoO nanotubes showed nearly doubled lithium ion intercalation and a coulombic efficiency of 96 % after 100 cycles compared to lower effective TiO 2 nanotubes prepared under identical conditions. The observed enhancement in the electrochemical performances could be attributed to increasing Li ion diffusion resulting from the presence of CoO nanotubes and the high surface area of the grown oxide tubes. The TiO 2 /CoO electrodes preserved their tubular structure after electrochemical cycling with only little changes in morphology.

Nitrogen-doped carbon-coated Ti–Fe–O nanocomposites with enhanced reversible capacity and rate capability for high-performance lithium-ion batteries

“…the better reversibility and faster Li + diffusion in S1−2C. 53 The CV results validate the vital role of TiO 2 in maintaining the structure stability of the composite and improving the electrochemical performance of the Ti−Fe−O nanocomposites. Accordingly, even a small fraction of structural stable TiO 2 could enhance the Li-ion storage performance of S1−2C to exceed that of S1−3C.…”

One-step synthesis of Li-doped NiO as high-performance anode material for lithium ion batteries

“…Transition metal oxides (TMOs), such as CoO x [12][13][14][15][16][17], CuO [18][19][20][21][22], SnOx [23][24][25], MnOx [26,27], CoMn 2 O 4 [28,29], ZnMn 2 O 4 [30] and MnCo 2 O 4 [31], have been widely studied as promising alternative anode materials for replacing the graphite used in LIBs for their high theoretical capacities. In particular, NiO is one of the promising anode materials for Li ion batteries because of its low cost and environmental friendless [32][33][34][35][36][37].…”

Electrochemical In Situ Formation of a Stable Ti‐Based Skeleton for Improved Li‐Storage Properties: A Case Study of Porous CoTiO3 Nanofibers

“…From Figure d, e, the main signals of the Co 2p 3/2 (779.808 eV) and Co 2p 1/2 (795.508 eV) doublet are separated by 15.7 eV, which indicates the presence of Co 2+ . Remarkably, the binding energy for Co 2p in the CoTiO 3 nanofibers shifted to a lower binding energy compared with Co 2p in CoO (780.0 and 795.9 eV for Co 2p 3/2 and Co 2p 1/2 ) . Similarly, it can also be seen that the binding energy for Ti 2p in CoTiO 3 shifts to lower binding energy compared with that of pure TiO 2 .…”

“…To enhance the cycling stability of TMOs, two of the most common methods without carbon co‐action have been explored. The first is the preparation of diverse nanoscale structures, such as nanofibers, nanowires, nanotubes, nanosheets . Compared with bulk materials, nanostructured ones can provide much shorter ion‐diffusion distances and higher surface‐to‐volume ratios, which are beneficial to enhance the rate performance and increase the actual Li‐storage capacity.…”

“…For example, Madian et al. have demonstrated the synthesis of TiO 2 –CoO hybrid nanotubes that showed a specific capacity of 280 mAh g −1 after 100 cycles at 50 mA g −1 . Unfavorably, to prepare such BTMOs with a uniform distribution of both oxide constituents, complicated and precisely controlled procedures are usually needed, which makes it hard to achieve scaled production.…”