In situ growth of MnO@Na₂Ti₆O₁₃ heterojunction nanowires for high performance supercapacitors

Abstract

One-dimensional tunnel and layer frame crystal structure materials are extremely attractive for energy storage in electrode materials. The energy storage properties of the electrode materials depend on their conductivity. Furthermore, the conductivity of electrode materials can be tailored through combination or doping with other materials, which transforms their properties from semiconductor to semimetallic or metallic and allow them to show unequaled performance for storage devices. In this work, heterostructures of manganese oxide (MnO) and modified sodium titanate (Na 2 Ti 6 O 13 ) (MnO@Na 2 Ti 6 O 13 ) nanowires are attained by the in situ thermal decomposition method. The heterojunction between MnO and Na 2 Ti 6 O 13 allows the semiconductor properties of pure Na 2 Ti 6 O 13 to show remarkable metallic behavior for improving the electrochemical performance. The capacitance of MnO@Na 2 Ti 6 O 13 heterojunction nanowires can reach 272.3 F g −1 , a power intensity of 250 W kg −1 at the energy density of 37.83 Wh kg −1 and retain 5000 W kg −1 at 6.67 Wh kg −1 as well. The energy storage mechanism of the MnO@Na 2 Ti 6 O 13 heterostructure is studied by density functional theory. All of the results show that the MnO@Na 2 Ti 6 O 13 heterostructure material has the potential to be an excellent supercapacitor material in the future.

Sodium Hexa-Titanate Nanowires Modified with Cobalt Hydroxide Quantum Dots as an Efficient and Cost-Effective Electrocatalyst for Hydrogen Evolution in Alkaline Media

“…It has high structural stability but suffers from low conductivity . Reports show that coating or doping treatments can be beneficial . Herein, we introduce a novel electrocatalyst using deposited Co­(OH) 2 QDs as an active material to improve the electrocatalytic performance of a modified TiO 2 -based substrate with a well-defined nanowire structure.…”

“…29 Reports show that coating or doping treatments can be beneficial. 31 Herein, we introduce a novel electrocatalyst using deposited Co(OH) 2 QDs as an active material to improve the electrocatalytic performance of a modified TiO 2 -based substrate with a well-defined nanowire structure. The nanowire substrate has a sodium hexa-titanate composition and was successfully fabricated via a hydrothermal technique followed by annealing where the interwoven nanowire structure is preserved.…”

K2Ti6O13 Nanoparticle-Loaded Porous rGO Crumples for Supercapacitors

“…The highest energy density of our work was 34.4 Wh kg −1 at a power density of 450 W kg −1 and the highest power density of 9000 W kg −1 at an energy density of 27.9 Wh kg −1 . Such high output energy and power densities were highly competitive compared to those of the recently reported alkali metal titanate-based supercapacitor devices [7,14,15,[29][30][31]].…”

High-rate transition metal-based cathode materials for battery-supercapacitor hybrid devices

“…[145][146][147] With built-in fields caused by the mismatch of energy band from different materials, electron transfer on the interface of heterojunction would be promoted by an electrostatic force, thus improving the kinetics of redox reactions during charging and discharging. 90,148,149 interaction with the electrolyte shortening the ion diffusion distance. 82 The SiC NWS@Ni(OH) 2 electrode material showed excellent rate performance, that is, 1724 F/g at 2 A/g, 1412 F/g at 100 A/g and a capacity retention of 81.9%.…”