Nanostructured V2O5 arrays on metal substrate as binder free cathode materials for sodium-ion batteries

Electrochemical Properties of Na0.66V4O10 Nanostructures as Cathode Material in Rechargeable Batteries for Energy Storage Applications

We report the electrochemical performance of nanostructures of Na0.66V4O10 as cathode material for rechargeable batteries. The Rietveld refinement of room-temperature X-ray diffraction pattern shows the monoclinic phase with C2/m space group. The cyclic voltammetry curves of prepared half-cells exhibit redox peaks at 3.1 and 2.6 V, which are due to two-phase transition reaction between V5+/4+ and can be assigned to the single-step deintercalation/intercalation of Na ion. We observe a good cycling stability with specific discharge capacity (measured vs Na+/Na) between 80 (±2) and 30 (±2) mAh g-1 at current densities of 3 and 50 mA g-1, respectively. The electrochemical performance of Na0.66V4O10 electrode was also tested with Li anode, which showed higher capacity but decayed faster than Na. Using density functional theory, we calculate the Na vacancy formation energies: 3.37 eV in the bulk of the material and 2.52 eV on the (100) surface, which underlines the importance of nanostructures.

Vanadium-based nanowires for sodium-ion batteries

Sodium-ion batteries (SIBs) have received great attention because of the abundance source and low cost. To date, some Na⁺ storage materials have achieved great performance, but the larger Na⁺ radius and more complex Na⁺ storage mechanism compared with Li⁺ still limit the energy density and power density. This review systematically summarizes emerging synthetic technologies of vanadium-based materials from simple nanowires to complicated modified/optimized structures. In addition, vanadium-based nanowire materials are reviewed at both the cathode and anode side, and advantages and drawbacks are proposed to explain the challenges facing application of novel materials. Furthermore, a vanadium-based single-nanowire device is reported to reveal the Na⁺ storage mechanism, which contributes to the understanding of the reaction in SIBs. Finally, this review summarizes the current development challenges of SIBs and looks forward to the future development prospects of vanadium-based nanowires, providing a new direction for further applications of SIBs.

In situ synthesis of tin dioxide submicrorods anchored on nickel foam as an additive-free anode for high performance sodium-ion batteries

A hybrid of tin dioxide submicrorods anchored on conductive nickel foam (SnO₂ submicrorods-Ni foam) is in-situ synthesized via a hydrothermal and a subsequent heat treatment by using stannic chloride and sodium hydroxide as the starting materials. Characterization results indicate that the synthesized SnO₂ submicrorods has a length of ∼400 nm and a diameter of ∼150 nm anchoring tightly on Ni foam. The electrochemical properties of the material as an additive-free anode for sodium-ion batteries are investigated. And a comparative research of the reversible sodium storage properties between the additive-free electrode of SnO₂ submicrorods-Ni foam and the additive electrode of SnO₂ rod-assembly microspheres is carried out. The results demonstrate that the SnO₂ submicrorods-Ni foam is a highly attractive anode for sodium ion batteries, which could exhibit much better sodium storage properties than the SnO₂ rod-assembly microspheres and other reported SnO₂-based additive electrodes. The excellent sodium storage properties of the SnO₂ submicrorods-Ni foam electrode can be attributed to its structure advantages without additive-assistant, which increase sodium storage active sites, facilitate the electronic/ionic transport and stabilize the total electrode structure during charge-discharge process.

Self-supported one-dimensional materials for enhanced electrochromism

A reversible, persistent electrochromic change in color or optical parameter controlled by a temporarily applied electrical voltage is attractive because of its enormous display and energy-related applications. Due to the electrochemical and structural advantages, electrodes based on self-supported one-dimensional (1D) nanostructured materials have become increasingly important, and their impacts are particularly significant when considering the ease of assembly of electrochromic devices. This review describes recent advances in the development of self-supported 1D nanostructured materials as electrodes for enhanced electrochromism. Current strategies for the design and morphology control of self-supported electrodes fabricated using templates, anodization, vapor deposition, and solution techniques are outlined along with demonstrating the influences of nanostructures and components on the electrochemical redox kinetics and electrochromic performance. The applications of self-supported 1D nanomaterials in the emerging bifunctional devices are further illustrated.

Flexible Electrodes for Sodium-Ion Batteries: Recent Progress and Perspectives

Sodium-ion batteries (SIBs) are considered as promising alternatives to lithium-ion batteries (LIBs) for large-scale electrical-energy-storage applications due to the wide availability and the low cost of Na resources. Along with the avenues of research on flexible LIBs, flexible SIBs are now being actively developed as one of the most promising power sources for the emerging field of flexible and wearable electronic devices. Here, the recent progress on flexible electrodes based on metal substrates, carbonaceous substrates (i.e., graphene, carbon cloth, and carbon nanofibers), and other materials, as well as their applications in flexible SIBs, are summarized. Also, some future research directions for constructing flexible SIBs are proposed, with the aim of providing inspiration to the further development of advanced flexible SIBs.

Ni3S2 nanosheet-anchored carbon submicron tube arrays as high-performance binder-free anodes for Na-ion batteries

A binder-free Ni-supported Ni₃S₂/CST array electrode was prepared by a controllable route and exhibits high capacity and a long cycle life.

Rational selection of amorphous or crystalline V2O5 cathode for sodium-ion batteries

Amorphous and crystalline V₂O₅ cathodes in sodium ion batteries express inverse capacity values at low and high current densities.