Na₂Ti₃O₇/C Nanofibers for High‐Rate and Ultralong‐Life Anodes in Sodium‐Ion Batteries

Abstract

Na2Ti3O7/C nanofibers are successfully synthesized through an electrospinning process followed by hydrothermal treatment. The unique structure of these one‐dimensional nanofibers with two‐dimensional nanosheets on the surface is presumed to significantly shorten the diffusion routes for both electrons and ions. Meanwhile, the carbon matrix with a certain degree of graphitization can dramatically improve the overall conductivity. As a result, the Na2Ti3O7/C nanofiber electrode reveals an impressive electrochemical capability as the anode material of sodium‐ion batteries. It demonstrates a reversible capacity of 110 mA h g−1 after 500 cycles at a rate of 1 C. Moreover, with almost no capacity degradation, the discharge capacity of the Na2Ti3O7/C nanofiber electrode remains at 58 mA h g−1 after 1500 cycles at the high rate of 50 C. This superior electrochemical performance places the Na2Ti3O7/C nanofibers as an anode material with great promise for sodium‐ion batteries that could be applied in large‐scale energy storage.

Boosting the Electrochemical Performance of V2O3 by Anchoring on Carbon Nanotube Microspheres with Macrovoids for Ultrafast and Long‐Life Aqueous Zinc‐Ion Batteries

“…The Nyquist plots could be deconvoluted into semicircles and the linear part using the Randle‐type equivalent circuit in Figure S17, Supporting Information. [ 62–65 ] The semicircle that appears at high and middle frequency may be attributed to the charge transfer resistance ( R ct ) arising from Zn x (CF 3 SO 3 ) y (OH) 2x−y ∙ n H 2 O precipitate at the surface, which is a zincate byproduct formed from competitive parasitic H 2 evolution, and the electrode materials, respectively. [ 33,66,67 ] The total R ct as a function of potential is shown in Figure 8d.…”

Fe‐Doped CoP Flower‐Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage

“…Thereby,t he surfaced oublelayer capacitance is dominant at high scan rates. [59,60] The ratio of surfacec apacitance in pure CoP/CM is much lower than that in Fe-doped CoP/CM.E ven at the scan rate of 1.0 mV s À1 , the surfacec apacitance in the total electrochemical capacity of the pure CoP/CMi so nly about 31.63 % ( Figure 5f). The diffusion-controlled process is dominanti nt he sodium storage process of pure CoP/CM.…”

“…The high scan rate facilitates the sodium ion diffusion in Fe‐doped CoP/CM (Figure c). Thereby, the surface double‐layer capacitance is dominant at high scan rates . The ratio of surface capacitance in pure CoP/CM is much lower than that in Fe‐doped CoP/CM.…”

Double‐shell and yolk‐shell structured ZnSe ‐carbon nanospheres as anode materials for high‐performance potassium‐ion batteries

“…28 The low intensity ratio of I D /I G (0.98) could be attributed to a graphitization of hollow carbon nanospheres occurring during selenization process. 29,30 The TG curve of d-ZnSe@HC measured in air atmosphere, as displayed in Figure S5, showed a two-step weight variation. The initial weight increase-up to 352.2 C was related to the partial oxidation of ZnSe to ZnSeO x .…”