Alumina - Stabilized SEI and CEI in Potassium Metal Batteries

Pengcheng Liu; Hongchang Hao; Aditya Singla; Bairav S Vishnugopi; John Watt; Partha P Mukherjee; David Mitlin

doi:10.1002/anie.202402214

Alumina - Stabilized SEI and CEI in Potassium Metal Batteries

Angew Chem Int Ed Engl. 2024 May 14:e202402214. doi: 10.1002/anie.202402214. Online ahead of print.

Authors

Pengcheng Liu¹, Hongchang Hao¹, Aditya Singla², Bairav S Vishnugopi², John Watt³, Partha P Mukherjee², David Mitlin⁴

Affiliations

¹ The University of Texas at Austin, Materials Science and Engineering Program & Texas Materials Institute (TMI), 2501 Speedway, EER 4.646, 78712, AUSTIN, UNITED STATES.
² Purdue University, School of Mechanical Engineering, 610 Purdue Mall, 47907, West Lafayette, UNITED STATES.
³ Los Alamos National Laboratory, Center for Integrated Nanotechnologies, 1515 Eubank Boulevard Southeast, BULDING 518, ROOM 1224, 87545, Los Alamos, UNITED STATES.
⁴ The University of Texas at Austin, Department of Mechanical Engineering, 2501 Speedway, 78712-1591, Austin, UNITED STATES.

PMID: 38745375
DOI: 10.1002/anie.202402214

Abstract

Aluminum oxide (Al2O3) nanopowder is spin-coated onto both sides of commercial polypropene separator to create artificial solid-electrolyte interphase (SEI) and artificial cathode electrolyte interface (CEI) in potassium metal batteries (KMBs). This significantly enhances the stability, including of KMBs with Prussian Blue (PB) cathodes. For example, symmetric cells are stable after 1,000 cycles at 0.5 mA/cm2 - 0.5 mAh/cm2 and 3.0 mA/cm2 - 0.5 mAh/cm2. Alumina modified separators promote electrolyte wetting and increase ionic conductivity (0.59 vs. 0.2 mS/cm) and transference number (0.81 vs. 0.23). Cryo-stage focused ion beam (cryo-FIB) analysis of cycled modified anode demonstrates dense and planar electrodeposits, versus unmodified baseline consisting of metal filaments (dendrites) interspersed with pores and SEI. Alumina-modified CEI also suppresses elemental Fe crossover and reduces cathode cracking. Mesoscale modeling of metal - SEI interactions captures crucial role of intrinsic heterogeneities, illustrating how artificial SEI affects reaction current distribution, conductivity and morphological stability.

Keywords: metal dendrite, potassium metal battery, electron microscopy, multiscale simulation, functional separator, solid electrolyte interphase (SEI).