Sodium-ion batteries (SIBs) have been considered as the most promising candidate for large-scale energy storage system owing to the economic efficiency resulting from abundant sodium resources, superior safety, and similar chemical properties to the commercial lithium-ion battery Despite the long period of academic research, how to realize sodium-ion battery commercialization for market applications is still a great challenge Thus, from the perspective of future practical application, this review will identify the factors that are restricting commercialization, and evaluate the existing active materials and sodium-ion-based full-cell system The design and development trends that are needed for SIBs to meet the requirements of practical applications in large-scale energy storage will also be discussed in detail

Sodium-Ion Batteries: From Academic Research to Practical Commercialization

https://dr.ntu.edu.sg/bitstream/10356/137055/2/Thermochromic%20VO2%20for%20Energy-Efficient%20Smart%20Windows.pdf

Thermochromic VO2 for Energy-Efficient Smart Windows

Recent advances of electrode materials for low-cost sodium-ion batteries towards practical application for grid energy storage

Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na3V2(PO4)3 and NaTi2(PO4)3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na3MnCO3PO4 and amorphous FePO4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.

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Polyanion-Type Electrode Materials for Sodium-Ion Batteries.

Room-temperature sodium-ion batteries (SIBs) are regarded as promising candidates for smart grids and large-scale energy storage systems (EESs) due to their significant benefits of abundant and low-cost sodium resource. Among the previously reported cathode materials for SIBs, layered transition-metal oxides and polyanion-type materials are considered to be the most attractive options. Although many layered transition-metal oxides can provide high capacity due to their small molecular weight, their further application is hindered by low output voltage (mostly lower than 3.5 V), irreversible phase transition as well as storage instability. Comparatively, polyanion-type materials exhibit higher operating potentials due to the inductive effect of polyanion groups. Their robust 3D framework significantly decreases the structural variations during sodium ion de/intercalation. Moreover, the effect of strong X-O (X = S, P, Si, etc.) covalent bonds can effectively inhibit oxygen evolution. These advantages contribute to the superior cycle stability and high safety of polyanion-type materials. However, low electronic conductivity and limited capacity still restrict their further application. This review summarizes the recent progress of polyanion-type materials for SIBs, which include phosphates, fluorophosphates, pyrophosphates, mixed phosphates, sulfates, and silicates. We also discuss the remaining challenges and corresponding strategies for polyanion-type materials. We hope this review can provide some insights into the development of polyanionic materials.

Polyanion-type cathode materials for sodium-ion batteries

The development of excellent performance of Na-ion batteries remains great challenge owing to the poor stability and sluggish kinetics of cathode materials. Herein, B substituted Na3V2P3-x B x O12 (0 ≤ x ≤ 1) as stable cathode materials for Na-ion battery is presented. A combined experimental and theoretical investigations on Na3V2P3-x B x O12 (0 ≤ x ≤ 1) are undertaken to reveal the evolution of crystal and electronic structures and Na storage properties associated with various concentration of B. X-ray diffraction results indicate that the crystal structure of Na3V2P3-x B x O12 (0 ≤ x ≤ 1/3) consisted of rhombohedral Na3V2(PO4)3 with tiny shrinkage of crystal lattice. X-ray absorption spectra and the calculated crystal structures all suggest that the detailed local structural distortion of substituted materials originates from the slight reduction of V-O distances. Na3V2P3-1/6B1/6O12 significantly enhances the structural stability and electrochemical performance, giving remarkable enhanced capacity of 100 and 70 mAh g-1 when the C-rate increases to 5 C and 10 C. Spin-polarized density functional theory (DFT) calculation reveals that, as compared with the pristine Na3V2(PO4)3, the superior electrochemical performance of the substituted materials can be attributed to the emergence of new boundary states near the band gap, lower Na+ diffusion energy barriers, and higher structure stability.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201600112

Boron Substituted Na3V2(P1−xBxO4)3 Cathode Materials with Enhanced Performance for Sodium‐Ion Batteries

NaV3(PO4)(3)/C nanocomposite as novel anode material for Na-ion batteries with high stability

Vanadium dioxide (VO2) is one of the most promising thermochromic materials with a reversible metal–insulator transition (MIT) from a high-temperature rutile phase to a low-temperature monoclinic phase, although a high MIT temperature (Tc) of 340 K for bulk VO2 restricts its wide application. Our first-principles calculations show that the oxygen nonstoichiometry plays an important role in tuning the MIT behavior of VO2. The O-vacancy in bulk VO2 gives rise to an increase in electron concentration, which induces a decrease in Tc. On the other hand, O-vacancy and O-adsorption on VO2(R) (1 1 0) and VO2(M) (0 1 1) surfaces could alter their work functions and in turn regulate Tc. In addition, the formation and adsorption energies of O-adsorption on the two types of surfaces are negative, indicating that VO2 surfaces are prone to oxidation in ambient air. The present results contribute to both tuning phase transition behaviors experimentally and reducing hindrances for the advanced applications of VO2-based materials.

Tuning the phase transition temperature, electrical and optical properties of VO2 by oxygen nonstoichiometry: insights from first-principles calculations

Xiaofang Wang

Papers

Boron Substituted Na3V2(P1−xBxO4)3 Cathode Materials with Enhanced Performance for Sodium‐Ion Batteries

NaV3(PO4)(3)/C nanocomposite as novel anode material for Na-ion batteries with high stability

Tuning the phase transition temperature, electrical and optical properties of VO2 by oxygen nonstoichiometry: insights from first-principles calculations

Tuning the work function of VO 2 (1 0 0) surface by Ag adsorption and incorporation: Insights from first-principles calculations

Energetics, electronic and optical properties of X (X = Si, Ge, Sn, Pb) doped VO2(M) from first-principles calculations