Metal phosphides embedded with in situ-formed metal phosphate impurities as buffer materials for high-performance potassium-ion batteries

Shunping Ji, Chunyan Song, Junfeng Li, Kwan San Hui, Wenjun Deng, Shuo Wang, Haifeng Li, Duc Anh Dinh, Xi Fan, Shuxing Wu, Jintao Zhang, Fuming Chen, Zongping Shao, Kwun Nam Hui

Research output: Contribution to journalArticlepeer-review

Abstract

As anodes for metal-ion batteries, metal phosphides usually suffer from severe capacity degradation because of their huge volume expansion and unstable solid electrolyte interphase (SEI), especially for potassium-ion batteries (PIBs). To address these issues, this study proposes amorphous phosphates acting as buffer materials. Ten types of metal phosphide composites embedded with in situ-formed amorphous phosphates are prepared by one-step ball milling using red phosphorus (RP) and the corresponding metal oxides (MOs) as starting materials. A zinc phosphide composite is selected for further study as a PIB anode. Benefitting from the effective suppression of volume variation, a KF-rich SEI is formed on the electrode surface in the KFSI-based electrolyte. The zinc phosphide composite exhibits a high reversible specific capacity and outstanding long-term cycling stability (476 mAh g −1 over 350 cycles at 0.1 A g −1 after going through a rate capability test and 177 mAh g −1 after 6000 cycles at 1.0 A g −1) and thus achieves the best cycling performance among all reported metal phosphide-based anodes for PIBs. This study highlights a low-cost and effective strategy to guide the development of metal phosphides as high-performance anodes for PIBs.

Original languageEnglish
Article number2101413
JournalAdvanced Energy Materials
Volume11
Issue number40
Early online date15 Sep 2021
DOIs
Publication statusPublished - 27 Oct 2021

Keywords

  • PIBs
  • SEI
  • amorphous phosphates
  • buffer volume expansion
  • metal phosphide anodes

Cite this