In situ ultrasound acoustic measurement of the lithium-ion battery electrode drying process

Ye Shui Zhang, Anand Narayanan Pallipurath Radhakrishnan, James B Robinson, Rhodri E Owen, Thomas G Tranter, Emma Kendrick, Paul R Shearing, Dan J L Brett

Research output: Contribution to journalArticlepeer-review

Abstract

The electrode drying process is a crucial step in the manufacturing of lithium-ion batteries and can significantly affect the performance of an electrode once stacked in a cell. High drying rates may induce binder migration, which is largely governed by the temperature. Additionally, elevated drying rates will result in a heterogeneous distribution of the soluble and dispersed binder throughout the electrode, potentially accumulating at the surface. The optimized drying rate during the electrode manufacturing process will promote balanced homogeneous binder distribution throughout the electrode film; however, there is a need to develop more informative in situ metrologies to better understand the dynamics of the drying process. Here, ultrasound acoustic-based techniques were developed as an in situ tool to study the electrode drying process using NMC622-based cathodes and graphite-based anodes. The drying dynamic evolution for cathodes dried at 40 and 60 °C and anodes dried at 60 °C were investigated, with the attenuation of the reflective acoustic signals used to indicate the evolution of the physical properties of the electrode-coating film. The drying-induced acoustic signal shifts were discussed critically and correlated to the reported three-stage drying mechanism, offering a new mode for investigating the dynamic drying process. Ultrasound acoustic-based measurements have been successfully shown to be a novel in situ metrology to acquire dynamic drying profiles of lithium-ion battery electrodes. The findings would potentially fulfil the research gaps between acquiring dynamic data continuously for a drying mechanism study and the existing research metrology, as most of the published drying mechanism research studies are based on simulated drying processes. It shows great potential for further development and understanding of the drying process to achieve a more controllable electrode manufacturing process.

Original languageEnglish
Pages (from-to)36605–36620
Number of pages16
JournalACS Applied Materials & Interfaces
Volume13
Issue number30
Early online date23 Jul 2021
DOIs
Publication statusPublished - 4 Aug 2021

Keywords

  • LIBs
  • electrode drying process
  • ultrasound acoustic measurement
  • drying dynamics
  • drying mechanism
  • General Materials Science

ASJC Scopus subject areas

  • Materials Science(all)

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