Novel technique holds potential for developing viable anode-free solid-state batteries

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The figure shows a) Schematic diagram of the working principle in an anode-free all-solid-state battery. Dendrite formation is suppressed by first forming a lithiophilic Li₂Te-Cu current collector which promotes uniform wetting of lithium metal. b) Cryogenic focused ion beam (cryo-FIB) reveals uniform lithium deposition and no dendrite formation. c) Anode-free ASSB cycling performance of the lithiophilic Li₂Te-Cu current collector showing much better performance than when a bare copper current collector is used.

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Anode-free all-solid-state batteries hold potential as promising energy storage devices due to their high energy capacity and safety features. In particular, sulfide solid-state electrolytes used in these batteries display highly promising ionic conductivities and offer advantages over lithium metal-based versions. However, sulfide solid-state electrolytes  still suffer from several major shortcomings. One key issue is the reactivity between the sulfides and both electrodes, which leads to an impedance rise associated with the formation of a mixed conducting interphase.

Using the unique capabilities available at the Center for Integrated Nanotechnologies, a team of researchers achieved a stable anode-free all-solid-state battery with a sulfide-based solid-electrolyte by tuning the wetting properties of lithium metal on the copper current-collector. Lithiophilic 1 micrometer Li₂Te is synthesized by exposing the collector to tellurium vapor, followed by in situ lithium activation during the first charge, which promotes uniform wetting of lithium metal, and suppresses dendrite formation. Their work paves the way for viable anode-free all-solid-state batteries that deliver significantly higher specific energies and cost less than all-solid-state batteries with excess lithium sources. Advanced Materials published the work.

Cryogenic focused ion beam (cryo-FIB) milling and cryo-SEM analysis of the solid-state electrolyte-electrode interface was performed at the Center for Integrated Nanotechnologies using the Scios 2 dual beam focused ion beam scanning electron microscope with a Leica VCT cryogenic stage and X-ray energy dispersive spectroscopy detector. To preserve the structural integrity of the beam-sensitive lithium-based materials and to reduce artificial inclusion, the sample was cooled to minus 150 degrees Celsius.

Funding and mission

This work is funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences; the Center for Integrated Nanotechnologies is an Office of Science User Facility operated for the DOE Office of Science. The research supports the Laboratory Energy Security mission and the Materials for the Future capability pillar.

Reference

“Stable anode-free all-solid-state lithium battery through tuned metal wetting on the copper current collector,” Advanced Materials, 2206762 (2022); DOI: 10.1002/adma.202206762. Authors: Yixian Wang, Yijie Liu, Mai Nguyen, Jaeyoung Cho, Naman Katyal, Hongchang Hao, Ruyi Fang, Nan Wu, Pengcheng Liu, Graeme Henkelman, David Mitlin (The University of Texas at Austin); Bairav S. Vishnugopi and Partha P. Mukherjee (Purdue University); Jagjit Nanda (SLAC National Laboratory); and John Watt (Los Alamos National Laboratory).

Technical contact: John Watt (MPA-CINT)