Multi-Redox (V5+/V4+/V3+/V2+) Driven Asymmetric Sodium (De)intercalation Reactions in NASICON-Na3VIn(PO4)3 Cathode. Issue 5 (25th May 2021)

• Record Type: Journal Article
• Authors: Ghosh, Subham; Jose, Nirmal; Senthilkumar, Baskar; Amonpattaratkit, Penphitcha; Senguttuvan, Premkumar
• Is Part Of: Journal of the Electrochemical Society. Volume 168:Issue 5(2021)
• Publication Date: 2021-05-25
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac001d
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : NASICON-Na3 V2−x Mx (PO4 )3 (M = Al 3+, Cr 3+, Fe 3+ & Ga 3+ ) cathodes are attractive for sodium-ion battery application due to their high voltage multi-redox (V 5+ /V 4+ /V 3+ ) couples and faster sodium-ion diffusivity. However, they suffer from rapid capacity decay due to irreversible structural changes occurring at high voltages. Herein, we present the structural and electrochemical sodium (de)intercalation properties of NASICON-Na3 VIn(PO4 )3 (NVIP) cathode. Although, this In 3+ -substituted cathode also undergoes similar high voltage structural degradation, but its structure is rejuvenated through the following low voltage deep-sodiation process, resulting in reversible capacities of ∼145 mA h g −1 (i.e., equivalent to ∼2.82 moles of Na per vanadium). Our combined electrochemical, in-operando X-ray diffraction and exsitu X-ray absorption spectroscopy analyses reveal asymmetric sodium (de)intercalation pathways of the NVIP cathode in the window of 4.2–1.2 V vs Na + /Na 0 that is driven by multi-redox (V 5+ /V 4+ /V 3+ /V 2+ ) couples.