Integrating Nanoreactor with O–Nb–C Heterointerface Design and Defects Engineering Toward High‐Efficiency and Longevous Sodium Ion Battery

Abstract

Sodium‐ion batteries (SIBs) have attracted much attention for their advantages of high operating voltage, environmental friendliness and cost‐effectiveness. However, the intrinsic defects of anode materials (such as poor electrical conductivity, sluggish kinetics, and large volume changes) hinder them from meeting the requirements for practical applications. Herein, a Nb2O5@carbon nanoreactor containing both a O–Nb–C heterointerface and oxygen vacancies (Nb2O5‐x@MEC) as an anode material is designed to drive SIBs toward extraordinary capacity and ultra‐long cycle life. The heterostructured nanoreactor both effectively immobilizes defective Nb2O5 by forming O‐Nb‐C heterointerface and offers homogeneous dispersion of Nb2O5 with desirable content to prevent their agglomeration. In addition, vast active interfaces, favored electrolyte infiltration, and a well‐structured ion–electron transportation channel are enabled by the framework, improving sodium ion storage and enhancing redox reaction kinetics. The enhancement brought by spatial confinement, defect implantation and heterointerface design give the composites a highly reversible sodiation–desodiation process and remarkable structural stability. By virtue of these superiorities, Nb2O5‐x@MEC delivers excellent performance, i.e., high areal capacity over 1.1 mAh cm‐2, admirable rate capability up to 20 A g‐1, and ultra‐long cycling performance over 5000 cycles, holding great promise for utilization in practically viable SIBs.

Controllable vacancy strategy mediated by organic ligands of nickel fluoride alkoxides for high-performance aqueous energy storage

“…5e shifted to lower binding energies in the charged/discharged states, which can be attributed to the increased electron density near the Ni atom and the elevated vacancy content after preactivation. 60–64 Meanwhile, the Ni 2p spectrum revealed a lower Ni 2+ /Ni 3+ ratio in the charged state than in the discharged state, indicating the redox valence of Ni 2+ /Ni 3+ achieved through reversible conversion between NiOOH and Ni(OH) 2 . As shown in Fig.…”

Pseudohexagonal Nb2O5 Anodes for Fast-Charging Potassium-Ion Batteries

“…Raman spectroscopy of Nb 2 O 5 @CNT was then performed to provide insights into the nature of the amorphous glucose-derived carbon (Figure b). The peaks centered at 676, 1351, and 1519 cm –1 correspond to vibrations of the Nb–O bonds, sp 3 carbons (D-band), and graphitic carbons (G-band), respectively. ,− In contrast to the Raman spectrum of pristine MWCNT, the intensity of graphitic carbon (G-band) is significantly higher than that of the disordered carbon (D-band) for Nb 2 O 5 @CNT, which may suggest that the hydrothermal treatment reduced the defect density in the framework of MWCNTs . Interestingly, this effect was not observed for gCNT, which was prepared using an equivalent hydrothermal method.…”

Defect-type AlOxnanointerface boosting layered Mn-based oxide cathode for wide-temperature sodium-ion battery

“…3c). 57,58 By comparing the fitted EIS curves of the two cathodes (Fig. 3d and Table S1, ESI†), it is clear that a lower charge transfer resistance ( R ct ) and higher Na + diffusion coefficient (2.207 × 10 −13 cm 2 s −1 ) existed in the NMA@AlO x cathode due to the surface coverage of the oxygen vacancy-containing AlO x layer.…”