A Theoretical study on the charge and discharge states of Na‐ion battery cathode material, Na 1+ x FePO 4 F

Cui

et al. 2023

Small

Sodium (Na)‐ion batteries (SIBs) have been considered as a potential device for large‐scale energy storage. To date, some start‐up companies have released their first‐generation SIBs cathode materials. Among them, phosphate compounds, particularly iron (Fe)‐based mixed phosphate compounds, present great potential for commercial SIBs owing to its low cost, environment friendly. In this perspective, a brief historical retrospect is first introduce to the development of Fe‐based mixed phosphate cathodes in SIBs. Then, the recent development about this kind of cathode has been summarized. One of the iron‐based phosphate materials, Na3Fe2(PO4)P2O7, is used as an example to roughly calculate the energy density and estimate the cost at the cell level to highlight their advantages. Finally, some strategies are put up to further increase the energy density of SIBs. This timely perspective aims to educate the community on the critical benefits of the Fe‐based mixed phosphate cathode and provide an up‐to‐date overview of this emerging field.

“…P21/b11 space group (Figure 2). [51] The theoretical calculation results are in good agreement with the previous experimental results.…”

Section: Fluorophosphates (Po 4 -F)supporting

confidence: 87%

Section: Fluorophosphates (Po 4 -F)mentioning

confidence: 99%

See 1 more Smart Citation

Perspective on Iron‐Based Phosphate Cathode for Commercial Sodium‐Ion Cells

Cui

et al. 2023

Small

“…[ 70 ] The phase transition was found between Na 2 FePO 4 F phase and NaFePO 4 F phase, as illustrated in Figure 10b. Furtherly, Yamashita group [ 71 ] revealed that Na 1.5 FePO 4 F with P 21 /b 11 space group is the only stable intermedia phase by using DFT calculations cooperated with experiment. The above‐mentioned intermedia phase was equally verified utilizing ssNMR (Figure 10c) combined with in situ XRD technology.…”

Section: Mixed‐polyanionsmentioning

confidence: 95%

Iron‐Phosphate‐Based Cathode Materials for Cost‐Effective Sodium‐Ion Batteries: Development, Challenges, and Prospects

Liang

et al. 2022

Adv Materials Inter

development, it is urgent to rummage and exploit renewable energy for instance solar energy, wind energy, nuclear energy, and tidal energy, etc. Large-scale energy storage systems (ESSs) are necessary and critical to integrate the above-mentioned intermittent energy into a continuous energy system, among which the electrochemical energy storage device is the most convenient, stable, and effective way for grid-connected forthputting. [2] Lithiumion batteries have been commercialized in the fields of electric vehicles, portable electronic devices, and electric tools, etc. since the 1990s. [3] Notably, lithium iron phosphate (LiFePO 4 ), one of the most important cathode materials for LIBs, is a potential candidate for large-scale energy storage due to its long lifespan, low toxicity, and outstanding thermal stability.

Advanced Energy Materials

“…Yamashita group employed first principle calculation along with Monte Carlo method to analyze the (dis)charge mechanism of NFPF. [ 202 ] They found the most stable structure of Na 1.5 FePO 4 F having monoclinic structure (s.g. P 2 1 / b 11). Indeed, structural evolution during (de)insertion in Na 2 FePO 4 F still remains vague warranting further research.…”

Section: Fluorophosphatesmentioning

confidence: 99%

Fluorophosphates: Next Generation Cathode Materials for Rechargeable Batteries

Sharma

Adiga

Alshareef

et al. 2020

steadily depleting. These realities have triggered significant efforts to harness renewable energy sources like hydro, solar, geothermal, or tidal energy that are intermittent in nature. Economic and sustainable energy storage devices can be coupled with renewable energy generators to realize uninterrupted energy supply. In this sector, rechargeable batteries form the most viable energy storage devices. Today, lithium-ion batteries dominate the electronics market due to their high volumetric and specific energy density. [1-5] The manifold consumption of lithium resources due to the booming multibillion-dollar industry and limited global lithium reserves have raised concerns over the future supply of Li-based precursors to cater to the large scale production of lithium-ion batteries. To alleviate this issue, various alternatives using earth-abundant elements (e.g., monovalent Na + /K + and multivalent Mg 2+ /Ca 2+ /Al 3+) have been proposed to replace LIBs. [6-10] The energy density of batteries is limited by the performance of cathodes. Thus, over the last five decades, three major types of insertion materials have been examined as cathodes for secondary batteries: layered transition metal oxides, Mn-based spinels, and polyanion type materials (Figure 1a). 2D layered transition metal oxides have been extensively studied, but issues like oxygen loss at high potentials raise safety concerns and hence oxides like LiCoO 2 or LiNi 1−x−y Co x Mn y O 2 (x < 1, y < 1) are mainly limited to small portable electronics. Though oxides deliver high energy density, they have lower redox potentials due to highly covalent MO bonding character. [11] This issue can be evaded by implementing 3D polyanionic cathode materials with tuneable (high) redox potential along with structural/thermal stability leading to safe battery operation. [12,13] Plethora of insertion materials have been reported with different polyanionic subunits [(XO 4