NaV(PO)-decorated NaV(PO)F as a high-rate and cycle-stable cathode material for sodium ion batteries.

Since NaV(PO) (NVP) possesses modest volume deformation and three-dimensional ion diffusion channels, it is a potential sodium-ion battery cathode material that has been extensively researched. Nonetheless, NVP still endures the consequences of poor electronic conductivity and low voltage platforms, which need to be further improved. On this basis, a high voltage platform NaV(PO)F was introduced to form a composite with NVP to increase the energy density.

Enhancing Sodium-Ion Transport by Hollow Nanotube Structure Design of a VS@C Anode for Sodium-Ion Batteries.

VS has received extensive attention in the field of sodium-ion batteries (SIBs) due to its two-dimensional (2D) layered structure, and weak van der Waals forces between V-S accelerate the transport of sodium ions. However, the long-term cycling of VS still suffers from volume expansion and low conductivity. Herein, a hollow nanotube VS@C (H-VS@C) with improved conductivity was synthesized by a solvothermal method to alleviate cracking caused by volume expansion.

Enhanced Li-Ion Diffusion and Cycling Stability of Ni-Free High-Entropy Spinel Oxide Anodes with High-Concentration Oxygen Vacancies.

High-entropy oxide (HEO) is an emerging type of anode material for lithium-ion batteries with excellent properties, where high-concentration oxygen vacancies can effectively enhance the diffusion coefficient of lithium ions. In this study, Ni-free spinel-type HEOs ((FeCoCrMnZn)O and (FeCoCrMnMg)O) were prepared via ball milling, and the effects of zinc and magnesium on the concentration of oxygen vacancy (O), lithium-ion diffusion coefficient (), and electrochemical performance of HEOs were investigated. Ab initio calculations show that the addition of zinc narrows down the band gap and thus improves the electrical conductivity.

Adjusting Crystal Orientation to Promote Sodium-Ion Transport in V S @Graphene Anode Materials for High-Performance Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have inspired the potential for widespread use in energy storage owing to the advantages of abundant resources and low cost. Benefiting from the layered structure, 2D-layered materials enable fast interlayer transport of sodium ions and thus are considered promising candidates as anodes for SIBs. Herein, a strategy of adjusting crystal orientation is proposed via a solvothermal method to improve sodium-ion transport at the edge of the interlayers in 2D-layered materials.

Ultrahigh-Rate Behavior Anode Materials of MoSe Nanosheets Anchored on Dual-Heteroatoms Functionalized Graphene for Sodium-Ion Batteries.

MoSe is a prospective anode material for Na-ion batteries because of its layered structure and high theoretical capacity, while the unsatisfied electrochemical performance limits its further development. Herein, we report MoSe nanosheets anchored on dual-heteroatoms functionalized graphene by a solvothermal method. The heteroatoms and carbon matrix coexist in the form of graphitic-N/pyridinic-N/pyrrolic-N and P-C/P═O bonds, which result in excellent electronic conductivity of the materials and provide abundant active sites for electrochemical process.

Formation and Effect of Residual Lithium Compounds on Li-Rich Cathode Material Li[NiMn]O.

Li-rich cathode materials are regarded as ideal cathode materials, owing to their excellent electrochemical capacity. However, residual lithium compounds, which are formed on the surface of the materials by reacting with moisture and carbon dioxide in ambient atmosphere, can impair the surface structure, injure the capacity, and impede the electrode fabrication using Li-rich materials. Exposure to air atmosphere causes the formation of residual lithium compounds; the formation of such compounds is believed to be related to humidity, temperature, and time during handling and storage.

Multiple Linkage Modification of Lithium-Rich Layered Oxide LiMnNiCoO for Lithium Ion Battery.

A multiple linkage modification (MLM) method was investigated to comprehensively improve the properties of lithium-rich layered oxides. MLM LiMnNiCoO was successfully synthesized via continuous and appropriate heat treatment. The synthesized LiMnNiCoO particles were coated with a LiZrO layer and doped with Zr by using a Zr compound as the MLM reagent.