Li Morphology Evolution during Initial Cycles in a Gel Composite Polymer Electrolyte

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Understanding and controlling lithium morphology evolution and lithium dendrite formation and growth during cycling is one of the key challenges for high-energy lithium metal batteries. This challenge applies to liquid electrolyte batteries as well as solid-state and semi-solid-state batteries. Our current knowledge about the evolution of the Li morphology is mostly obtained from liquid electrolyte-based studies in a Li-Li symmetrical cell configuration. The knowledge obtained in such conditions may not readily transfer into solid-state or semi-solid-state batteries. In this work, Li morphology evolution during initial cycling in a full cell configuration with the LiNi0.6Co0.2Mn0.2O2(NMC 622) cathode and a semi-solid-state gel composite electrolyte is monitored via post-mortem photographs and scanning electron microscopy at multiple length scales. The gel composite electrolyte contains a cross-linked poly(ethylene oxide)-based polymer electrolyte, ceramic fillers, and a liquid plasticizer. The results show that severe surface pitting occurs as early as the second stripping cycle. Pit formation and continuous dissolution during the stripping process are the main cause of the Li surface roughening and dendrite growth mechanism in the model gel composite electrolyte. Comparing Li dendrite growth mechanisms in liquid, polymer, and ceramic solid electrolytes, the dendrite growth mechanism observed in this model electrolyte resembles that of the liquid electrolyte the most. This study suggests that strategies to control Li morphology and prevent dendrite growth in a gel composite electrolyte should be similar to strategies applicable to liquid electrolytes.

Original languageEnglish
Pages (from-to)11362-11369
Number of pages8
JournalACS Applied Energy Materials
Volume5
Issue number9
DOIs
StatePublished - Sep 26 2022

Funding

This work was initiated under the support of the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL, managed by UT-Battelle, LLC for the U.S. Department of Energy) under Contract No. DE-AC05-00OR22725, and completed with the support of the Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research Program. The SEM in this work was performed and supported at the Center for Nanophase Materials Sciences in Oak Ridge National Lab, a DOE Office of Science user facility.

Keywords

  • ex-situ SEM
  • full cell configuration
  • gel composite polymer
  • lithium morphology evolution
  • pit formation
  • solid-state batteries

Fingerprint

Dive into the research topics of 'Li Morphology Evolution during Initial Cycles in a Gel Composite Polymer Electrolyte'. Together they form a unique fingerprint.

Cite this