Phase-Inversion Polymer Composite Separators Based on Hexagonal Boron Nitride Nanosheets for High-Temperature Lithium-Ion Batteries

Ana C.M. De Moraes, Woo Jin Hyun, Norman S. Luu, Jin Myoung Lim, Kyu Young Park, Mark C. Hersam

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


By preventing electrical contact between anode and cathode electrodes while promoting ionic transport, separators are critical components in the safe operation of rechargeable battery technologies. However, traditional polymer-based separators have limited thermal stability, which has contributed to catastrophic thermal runaway failure modes that have conspicuously plagued lithium-ion batteries. Here, we describe the development of phase-inversion composite separators based on carbon-coated hexagonal boron nitride (hBN) nanosheets and poly(vinylidene fluoride) (PVDF) polymers that possess high porosity, electrolyte wettability, and thermal stability. The carbon-coated hBN nanosheets are obtained through a scalable liquid-phase shear exfoliation method using ethyl cellulose as a polymer stabilizer and source of the carbon coating following thermal pyrolysis. When incorporated within the PVDF matrix, the carbon-coated hBN nanosheets promote favorable interfacial interactions during the phase-inversion process, resulting in porous, flexible, free-standing composite separators. The unique chemical composition of these carbon-coated hBN separators implies high wettability for a wide range of liquid electrolytes. This combination of high porosity and electrolyte wettability enables enhanced ionic conductivity and lithium-ion battery electrochemical performance that exceeds incumbent polyolefin separators over a wide range of operating conditions. The hBN nanosheets also impart high thermal stability, providing safe lithium-ion battery operation up to 120 °C.

Original languageEnglish
Pages (from-to)8107-8114
Number of pages8
JournalACS Applied Materials and Interfaces
Issue number7
Publication statusPublished - Feb 19 2020


  • hexagonal boron nitride
  • lithium-ion battery
  • phase-inversion
  • polymer composite
  • separator

ASJC Scopus subject areas

  • Materials Science(all)

Fingerprint Dive into the research topics of 'Phase-Inversion Polymer Composite Separators Based on Hexagonal Boron Nitride Nanosheets for High-Temperature Lithium-Ion Batteries'. Together they form a unique fingerprint.

Cite this