Spatially Resolved Potential and Li-Ion Distributions Reveal Performance-Limiting Regions in Solid-State Batteries

Published

October 19, 2021

Author(s)

Elliot Fuller, Evgheni Strelcov, Jamie Weaver, Michael Swift, Joshua Sugar, Andrei Kolmakov, Nikolai Zhitenev, Jabez J. McClelland, Yue Qi, Joseph Dura, Alec Talin

Abstract

The performance of solid-state electrochemical systems is intimately tied to the potential and lithium distributions across electrolyte–electrode junctions that give rise to interface impedance. Here, we combine two operando methods, Kelvin probe force microscopy (KPFM) and neutron depth profiling (NDP), to identify the rate-limiting interface in operating Si-LiPON-LiCoO2 solid-state batteries by mapping the contact potential difference (CPD) and the corresponding Li distributions. The contributions from ions, electrons, and interfaces are deconvolved by correlating the CPD profiles with Li-concentration profiles and by comparisons with first-principles-informed modeling. We find that the largest potential drop and variation in the Li concentration occur at the anode–electrolyte interface, with a smaller drop at the cathode–electrolyte interface and a shallow gradient within the bulk electrolyte. Correlating these results with electrochemical impedance spectroscopy following battery cycling at low and high rates confirms a long-standing conjecture linking large potential drops with a rate-limiting interfacial process.

Citation

ACS Energy Letters

Volume

6

Issue

11

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acsenergylett.1c01960

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Keywords

Kelvin probe force microscopy, neutron depth profiling, lithium ion conductor, lithium ion battery, solid electrolyte, first-principles calculations, electrochemical potential, solid state battery.

Citation

Fuller, E. , Strelcov, E. , Weaver, J. , Swift, M. , Sugar, J. , Kolmakov, A. , Zhitenev, N. , McClelland, J. , Qi, Y. , Dura, J. and Talin, A. (2021), Spatially Resolved Potential and Li-Ion Distributions Reveal Performance-Limiting Regions in Solid-State Batteries, ACS Energy Letters, [online], https://doi.org/10.1021/acsenergylett.1c01960, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932264 (Accessed May 4, 2024)