Stabilizing anionic redox processes in electrospun NiS2–based cathode towards durable aluminum-ion batteries

Junfeng Li, Kwan San Hui, Yunshan Zheng, Shunping Ji, Kaixi Wang, Chenyang Zha, Duc Anh Dinh, Xi Fan, Fuming Chen, Zongping Shao, Kwun Nam Hui

Research output: Contribution to journalArticlepeer-review

Abstract

Rechargeable aluminum-ion batteries (AIBs) are receiving considerable attention as a desirable device for large-scale energy storage owing to high theoretical capacity and abundance of aluminum. However, due to strong charge of Al 3+, the state-of-the-art AIBs often show sluggish electrode reaction kinetics and rapid capacity fading and the available cathode materials always demonstrate poor structural stability, thereby greatly hindering their practical use. NiS 2 with anion redox species (S 2 2– dimers) and favorable electronic conductivity is a promising cathode to boost the performance of AIBs in terms of reversible capacity, rate capability and cycling stability. Here, we report a systematic investigation of the Al storage behavior and mechanism of NiS 2/S-doped carbon (NiS 2/SC) cathode based on a series of electrochemical tests and ex situ measurements. We further develop electrospun NiS 2/S-doped carbon@S-doped carbon nanofiber (NiS 2/SC@SCNF) structure as the cathode of AIBs. The as-fabricated AIB delivers an unprecedented Al 3+ storage performance with a stable capacity of 76 mAh/g at 0.5 A/g CV 500 cycles and a superior cycling Coulombic efficiency of 97 %. This study reveals that NiS 2/SC@SCNF undergoes a reversible evolution of initial Al 3+ insertion followed by anionic redox between S 2 2– and S 2–, paving the road for the futher development of NiS 2–based cathodes for AIBs.

Original languageEnglish
Article number138237
JournalChemical Engineering Journal
Volume450
Issue numberPart 4
Early online date22 Jul 2022
DOIs
Publication statusE-pub ahead of print - 22 Jul 2022

Keywords

  • Aluminum-ion batteries
  • Anionic redox
  • Electrospun
  • NiS -based electrode

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