Study on Electrochemical Performance and Magnesium Storage Mechanism of Na 3 V 2 (PO 4 ) 3 @C Cathode in Mg(TFSI) 2 /DME Electrolyte

Jinxing Wang (), Peiyang Zhang, Xuan Mou, Jingdong Yang, Jiaxu Wang, Guangsheng Huang and Jingfeng Wang ()
Additional contact information
Jinxing Wang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Peiyang Zhang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Xuan Mou: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Jingdong Yang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Jiaxu Wang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Guangsheng Huang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
Jingfeng Wang: College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China

Energies, 2025, vol. 18, issue 22, 1-14

Abstract: Magnesium metal boasts a high theoretical volumetric specific capacity and abundant reserves. Magnesium batteries offer high safety and environmental friendliness. In recent years, magnesium-ion batteries (MIBs) with Mg or Mg alloys as anodes have garnered extensive interest and emerged as promising candidates for next-generation competitive energy storage technologies. However, MIBs are plagued by issues such as sluggish desolvation kinetics and slow migration kinetics, which lead to limitations including a limited electrochemical window and poor magnesium storage reversibility. Herein, the sodium vanadium phosphate @ carbon (Na 3 V 2 (PO 4 ) 3 @C, hereafter abbreviated as NVP@C) cathode material was synthesized via a sol–gel method. The electrochemical performance and magnesium storage mechanism of NVP@C in a 0.5 M magnesium bis(trifluoromethanesulfonyl)imide/ethylene glycol dimethyl ether (Mg(TFSI) 2 /DME) electrolyte were investigated. The as-prepared NVP@C features a pure-phase orthorhombic structure with a porous microspherical morphology. The discharge voltage of NVP@C is 0.75 V vs. activated carbon (AC), corresponding to 3.5 V vs. Mg/Mg 2+ . The magnesium storage process of NVP@C is tentatively proposed to follow a ‘sodium extraction → magnesium intercalation → magnesium deintercalation’ three-step intercalation–deintercalation mechanism, based on the characterization results of ICP-OES, ex situ XRD, and FTIR. No abnormal phases are generated throughout the process, and the lattice parameter variation is below 0.5%. Additionally, the vibration peaks of PO 4 tetrahedrons and VO 6 octahedrons shift reversibly, and the valence state transitions between V 3+ and V 4+ /V 5+ are reversible. These results confirm the excellent reversibility of the material’s structure and chemical environment. At a current density of 50 mA/g, NVP@C delivers a maximum discharge specific capacity of 62 mAh/g, with a capacity retention rate of 66% after 200 cycles. The observed performance degradation is attributed to the gradual densification of the CEI film during cycling, leading to increased Mg 2+ diffusion resistance. This work offers valuable insights for the development of high-voltage MIB systems.

Keywords: magnesium-ion batteries; Na 3 V 2 (PO 4 ) 3 @C; Mg(TFSI) 2 /DME electrolyte; magnesium storage reaction mechanism; electrochemical performance (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/18/22/5975/pdf (application/pdf)
https://www.mdpi.com/1996-1073/18/22/5975/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:18:y:2025:i:22:p:5975-:d:1794323

Access Statistics for this article

Energies is currently edited by Ms. Cassie Shen

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().