P2-type layered manganese-based oxides have attracted considerable interest as economical, cathode materials with high energy density for sodium-ion batteries (SIBs). Despite their potential, these materials still face challenges related to sluggish kinetics and structural instability. In this study, a composite cathode material, NaNiMnVO@NaVO(PO)F was developed by surface-coating P2-type NaNiMnVO with a thin layer of NaVO(PO)F to enhance both the electrochemical sodium storage and material air stability. The optimized NaNiMnVO@5wt %NaVO(PO)F exhibited a high discharge capacity of 176 mA h g within the 1.5-4.1 V range at a low current density of 17 mA g. At an increased current density of 850 mA g within the same voltage window, it still delivered a substantial initial discharge capacity of 112 mAh g. These findings validate the significant enhancement of ion diffusion capabilities and rate performance in the P2-type NaNiMnO material conferred by the composite cathode.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.202400088 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Beijing University of Technology, Materials Science and Technology, Pingleyuan 100#, Chaoyang District, 100124, Beijing, CHINA.
Manganese-based (Mn-based) layered oxides have emerged as competitive cathode materials for sodium-ion batteries (SIBs), primarily due to their high energy density, cost-effectiveness, and potential for mass production. However, these materials often suffer from irreversible oxygen redox reactions, significant phase transitions, and microcrack formation, which lead to considerable internal stress and degradation of electrochemical performance. This study introduces a high-entropy engineering strategy for P2-type Mn-based layered oxide cathodes (HE-NMCO), wherein a multi-ingredient cocktail effect strengthens the lattice framework by modulating the local environmental chemistry.
View Article and Find Full Text PDFSmall
December 2024
School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou, 510275, P. R. China.
NaNiMnO (NNM) is regarded as a promising cathode material for Na-ion batteries (NIBs), but suffers from irreversible phase transformations characterized by multiple voltage plateaus, resulting in poor cycle stability and inferior rate capability. To address these issues, the NaNiCuZnMnO (NNCZM) cathode material is synthesized by a cation chelation and reassembly process, which can promote a more uniform element distribution than that prepared by the solid-state method (S-NNCZM), resulting in better Na diffusion kinetics and rate capability. Replacing Ni with a small amount of Zn prevents the P2-O2 phase transformation, while replacing Ni with an appropriate amount of electrochemically active Cu eliminates Na-vacancy ordering and additionally contributes to capacity.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
Department of Chemistry and Life Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
A Mn-based sodium-containing layered oxide, P'2-type NaMnO, is revisited as a positive electrode material for sodium-ion batteries, and factors affecting its electrochemical performances are examined. The cyclability of NaMnO is remarkably improved by increasing the lower cut-off voltage during cycling even though the reversible capacity is sacrificed. Furthermore, the use of highly concentrated electrolytes, in which the presence of free solvent molecules is eliminated, effectively suppresses the dissolution of Mn ions, thus enabling stable cycling with >85% capacity retention for 300 continuous cycles.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
P2-type NaNiMnO cathodes have attracted attention due to their excellent stability and low cost, making them promising for sodium-ion batteries. However, their practical application is limited by a low capacity at lower voltages and severe phase transitions at higher voltage. To address these challenges, we report a material NaNiMnO-OVs (NNMO-OVs) with significantly slowed phase transitions at high voltage by introducing oxygen vacancies OVs into the P2/P3 mixed phase cathode NaNiMnO (NNMO).
View Article and Find Full Text PDFJ Am Chem Soc
November 2024
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, PR China.
Mn-based layered oxide cathodes have attracted widespread attention due to high capacity and low cost, however, poor air stability, irreversible phase transitions, and slow kinetics inhibit their practical application. Here, we propose a universal interfacial reconstruction strategy based on converting residual alkali to tunnel phase NaMnO for addressing the above mentioned issue simultaneously, using O3 NaNiFeMnO@2 mol % NaMnO (NaNFM@NMO) as the prototype material. The optimized material exhibits an initial capacity and energy density comparable with lithium-ion batteries.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!