Enhancing Lithium and Sodium Storage Properties of TiO2(B) Nanobelts by Doping with Nickel and Zinc

Abstract

Nickel- and zinc-doped TiO2(B) nanobelts were synthesized using a hydrothermal technique. It was found that the incorporation of 5 at.% Ni into bronze TiO2 expanded the unit cell by 4%. Furthermore, Ni dopant induced the 3d energy levels within TiO2(B) band structure and oxygen defects, narrowing the band gap from 3.28 eV (undoped) to 2.70 eV. Oppositely, Zn entered restrictedly into TiO2(B), but nonetheless, improves its electronic properties (Eg is narrowed to 3.21 eV). The conductivity of nickel- (2.24 × 10−8 S·cm−1) and zinc-containing (3.29 × 10−9 S·cm−1) TiO2(B) exceeds that of unmodified TiO2(B) (1.05 × 10−10 S·cm−1). When tested for electrochemical storage, nickel-doped mesoporous TiO2(B) nanobelts exhibited improved electrochemical performance. For lithium batteries, a reversible capacity of 173 mAh·g−1 was reached after 100 cycles at the current load of 50 mA·g−1, whereas, for unmodified and Zn-doped samples, around 140 and 151 mAh·g−1 was obtained. Moreover, Ni doping enhanced the rate capability of TiO2(B) nanobelts (104 mAh·g−1 at a current density of 1.8 A·g−1). In terms of sodium storage, nickel-doped TiO2(B) nanobelts exhibited improved cycling with a stabilized reversible capacity of 97 mAh·g−1 over 50 cycles at the current load of 35 mA·g−1.

A Comparative Study of the Influence of Nitrogen Content and Structural Characteristics of NiS/Nitrogen-Doped Carbon Nanocomposites on Capacitive Performances in Alkaline Medium

“…Among the existing EES devices, there is a complementary relationship between metal-ion batteries (MIBs) and supercapacitors (SCs) since the former has a high energy density, but the latter can deliver extreme power density [1][2][3][4][5]. It is recognized that increasing the power energy of the MIBs to as high as that of the SCs is intrinsically challenging, owing to the insertion/extraction of the metal ions from the corresponding electrode materials being principally essential, that is, the energy storage mechanism [6][7][8][9][10]. On the contrary, it has been demonstrated that several electrode materials that followed a redox reaction can provide more capacitances as compared with the traditionally used carbonaceous materials [11][12][13].…”

Unleashing the Potential of Sodium‐Ion Batteries: Current State and Future Directions for Sustainable Energy Storage

“…The electrochemical storage of bronze–TiO 2 (TiO 2 (B)) has been recently found to be improved by doping with Ni and Zn. [ 329 ] Their findings revealed that doping with 5 at% Ni (Ni/Ti ratio of 0.02/0.05/0.08) into TiO 2 (B) successfully dilates the unit cell by 4% and creates defects that reduce the energy bandgap from 3.28 to 2.70 eV. By contrast, Zn doping is highly restricted (Zn/Ti ratio 0.02/0.05); nevertheless, it significantly improves conductivity (3.29 × 10 −9 S cm −1 ), compared to that of the bare TiO 2 (B) (1.05 × 10 −10 S cm −1 ).…”

Bronze‐Phase TiO2 as Anode Materials in Lithium and Sodium‐Ion Batteries

“…Recently, TiO 2 (B) nanobelts were also reported to act as highperformance anode materials for LIBs. [188][189][190][191] Different strategies were applied to enhance the electrochemical performance of TiO 2 (B) nanobelt anodes, including compositing with other materials, [189] doping, [190] and surface engineering. [191] It has been demonstrated that anatase TiO 2 with exposed {001} facets could deliver better lithium storage performance than normal anatase TiO 2 .…”