Revealing Asymmetric Phase Transformation of the BiVO4 Anodes for Potassium-Ion Batteries by In Situ Transmission Electron Microscopy

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Quan An
  • Zelin Ma
  • Shiying Guo
  • Ying Wang
  • Weiwei Xia
  • Ran Cai
  • Hongqiang Wang

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)55490-55501
Journal / PublicationACS Applied Materials & Interfaces
Volume16
Issue number41
Online published5 Oct 2024
Publication statusPublished - 16 Oct 2024

Abstract

Potassium-ion batteries (PIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs), thanks to the cost-effectiveness of potassium resources and a favorable redox potential of approximately −2.936 V. The monoclinic BiVO4, known for its layered structure, shows noteworthy electrochemical properties when utilized as an anode material for both LIBs and sodium-ion batteries. However, the fundamental electrochemical reaction mechanisms of the BiVO4 anode during the potassium insertion/extraction processes remain unclear. Here, we constructed a BiVO4 anode PIB inside the transmission electron microscope (TEM) to explore the real-time potassiation/depotassiation behaviors of BiVO4 during electrochemical cycling. Utilizing the state-of-art in situ TEM technique, the BiVO4 nanorods are found to undergo an asymmetric phase transformation for the first time, where the pristine BiVO4 material is transformed into an amorphous KxBiVO4 phase after the first cycle. More interestingly, the anode materials near and far from the potassium source exhibit opposite volume-changing trends under the same voltage potential. Also, this phenomenon should be attributed to the mass flow of the unstable K−Bi alloy under the electric field. Our findings provide significant insights into the electrochemical mechanism of BiVO4 nanorods during the potassiation/depotassiation process, with the hope of assistance in designing anodes for high-performance PIBs. © 2024 American Chemical Society.

Research Area(s)

  • potassium-ion batteries, in situ TEM, BiVO4 anode, potassiationand depotassiation, asymmetric phase transformation

Citation Format(s)

Revealing Asymmetric Phase Transformation of the BiVO4 Anodes for Potassium-Ion Batteries by In Situ Transmission Electron Microscopy. / An, Quan; Zhang, Wenqi; Ma, Zelin et al.
In: ACS Applied Materials & Interfaces, Vol. 16, No. 41, 16.10.2024, p. 55490-55501.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review