Nitrogen-doped TiO₂ nanospheres for advanced sodium-ion battery and sodium-ion capacitor applications

Abstract

We synthesized nitrogen-doped anatase TiO2 nanospheres, and then used them as high-performance anode materials for NIBs and NICs, which were found to display enhanced electrochemical performances.

Flexible Quasi‐Solid‐State Sodium‐Ion Capacitors Developed Using 2D Metal–Organic‐Framework Array as Reactor

“…The energy density and power density values are calculated by integrating galvanostatic discharge curves and using the total mass of the two electrodes. The energy densities of the present quasi-solid-state NIC device are considerably higher than those values of the state-of-the-art reported NICs [23,[26][27][28][29][30][31][32][45][46][47] (Table S2, Supporting Information) and other energy storage systems such as lithium ion capacitors, [48][49][50] aqueous asymmetric SCs, [51,52] ionic liquid-based SCs, [33,53] and Ni/Fe batteries. Even at an extremely high power density of 48 kW kg −1 , the NIC can still deliver 49 W h kg −1 .…”

“…In a LIC, the capacitive cathode is typically a carbonaceous material that enables fast charge− discharge processes, while the reported battery-type anode includes Li 4 Ti 5 O 12 , [9,10] graphite, [11] TiO 2 , [12] MnO, [13] and LiVO 3 . Strategies to increase sodium ion (Na + ) and electron (e − ) transport kinetics of NIC electrodes reported so far include: (1) developing new electrode materials (such as 2D MXene Ti 2 C, [24] V 2 C), [25] (2) constructing more conductive electrode structures by hybridizing with carbon (such as NaTi 2 (PO 4 ) 3 /rGO, [26] C@NVP, [27] Nb 2 O 5 @C/rGO, [28] TiO 2 mesocages@rGO, [29] and (3) shortening the ion diffusion and electron transport lengths by rational designing nanostructures (such as TiO 2 nanospheres, [30] Ti(O,N) nanowires, [31] Na 2 Ti 3 O 7 nanosheets [32] ). [15][16][17][18][19][20][21][22] Despite the potential low-cost, constructing hybrid sodium ion capacitors (NICs) faces more challenge because most Na host materials have a rather sluggish kinetic due to the large Na ion sizes.…”

Micro/Nanostructured Materials for Sodium Ion Batteries and Capacitors

“…Heteroatom doping, such as by N and Nb, can induce the generation of trivalent titanium and oxygen vacancies and further improve the electrical conductivity of anatase TiO 2. Liu et al prepared N‐doped TiO 2 nanospheres as high‐rate anodes for SICs . Notably, the N‐TiO 2 //AC SICs delivered a high energy density of 80.3 W h kg −1 and a high power density of 12.5 kW kg −1 .…”

Green sol–gel route for selective growth of 1D rutile N–TiO2: a highly active photocatalyst for H2 generation and environmental remediation under natural sunlight

“…Among transition metal oxide photocatalysts, titania (TiO 2 ) has been an intensively investigated candidate within the ambit of various potential applications such as photocatalytic water splitting, 1-3 organic pollutant degradation, 4-7 supercapacitors, 8 dye sensitized solar cells (DSSC), [9][10][11][12] Li-ion battery photo anodes, 13,14 gas-sensors, 15,16 and super-hydrophilicity. 17 This can be ascribed to its fascinating electronic and optical properties, namely, favourable electronic band structure, non-toxicity, biocompatibility, long term chemical stability towards photo-corrosion, and, importantly, commercial cost-effectiveness.…”