Improved sodium-ion storage performance of TiO₂nanotubes by Ni²⁺doping

Abstract

TiO 2 is a promising applicable anode for sodium-ion batteries (SIBs) due to its inherent safety, low cost, good structural stability during sodium-ion storage process and appropriate voltage platform. However, unsatisfied electrical conductivity hinders its application. Here we demonstrate that doping of TiO 2 nanotubes with Ni 2+ via an initial sol-gel method, subsequent hydrothermal process and final thermal 10 treatment, which can balance the high conductivity and good structural stability of TiO 2 to improve the sodium-ion storage performance. The resultant sample exhibits a high charge capacity of 286 mA h g -1 after 100 cycles at a current density of 50 mA g -1 and even at a high current density of 5 A g -1 , a capacity of 123 mA h g -1 is maintained after 2000 cycles. It is believed that the strategy in this work can provide a useful pathway towards enhancing the electrochemical performance of TiO 2 anode for SIBs.

Evolution of the electrochemical interface in sodium ion batteries with ether electrolytes

“…2a where the Raman signal of TiO 2 can still be observed, indicating a lower accessible capacity than when using diglyme in the first cycle, and only after ~4 cycles is the TiO 2 completely transformed to the amorphous phase (Supplementary Figure 6). This incomplete sodiation of anatase TiO 2 has also been observed in an EC/PC (propylene carbonate)-based electrolyte 42 . The ex situ XRD results (Supplementary Figure 7) further prove the amorphization of the TiO 2 during the first discharge in the diglyme-based electrolyte and the incomplete sodiation in the EC/DEC-based electrolyte.…”

Ti‐Based Oxide Anode Materials for Advanced Electrochemical Energy Storage: Lithium/Sodium Ion Batteries and Hybrid Pseudocapacitors

“…Soon afterward, the anatase phase was partly recovered at charge state (2.5–3.0 V), as shown in Figure a. Pan and co‐workers and Lu and co‐workers further confirmed the conclusion from the TiO 2 nanotubes anodes and mesoporous single‐crystal‐like TiO 2 ‐graphene nanocomposite, respectively.…”

Glycol Derived Carbon- TiO2 as Low Cost and High Performance Anode Material for Sodium-Ion Batteries

“…The capacity contribution of the carbon additive is calculated to be to be less than 10 mAh g −1 , which is negligible. It is noteworthy that the reversible capacity of TiO 2 @C is possibly one of the highest capacities reported for the TiO 2 anodes232628.…”

“…Doping elements with low charge states can create structure defects in the bulk TiO 2 and thus enhance the electrical and ionic conductivities. Of significance, Pan et al 26. prepared Ni 2+ doped TiO 2 nanotubes with a maximum capacity of 286 mAh g −1 after 100 cycles at a current density of 50 mA g −1 .…”