Electrochemical Fluoridation of Manganese Oxide by Perfluorinated‐Gas Conversion for Lithium‐Ion Cathodes

Abstract

Fluoridation of Lithium‐ion (Li‐ion) cathodes is of growing interest for high‐capacity Li+ storage materials, but well‐controlled fluoridation processes are elusive. We investigated an electrochemical methodology to grow lithium fluoride (LiF) by reduction of perfluorinated gas onto metal oxides (MO), which then forms M−O−F by splitting of LiF upon charge, using MnO as an example target phase. Unlike current methods where particle size −/MnO, 340 mAh gMnO−1) is achieved with large MnO particle size (∼400 nm), exceeding comparable MnO/LiF systems reported to date. Additionally, incorporation of perfluorinated‐gas additive benefits cycling, with capacity of ∼270 mAh gMnO−1 retained after 20 cycles. This work demonstrates the opportunity for electrochemically driven fluoridation to achieve high capacities with larger particle sizes needed to bring oxyfluorides closer to practical reality.

Document Details

Document Type
Pub Defense Publication
Publication Date
Sep 03, 2021
Source ID
10.1002/batt.202100139

Entities

People

  • Betar M. Gallant
  • Haining Gao
  • Mingfu He
  • Rui Guo

Organizations

  • Army Research Office
  • Massachusetts Institute of Technology
  • National Science Foundation

Tags

Fields of Study

  • Materials science

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • ballistics.