In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2021-01, No. 8 ( 2021-05-30), p. 2100-2100
Abstract:
Silicon offers high theoretical capacity as a negative electrode material for lithium-ion batteries; however, high irreversible capacity upon initial cycling and poor cycle life have limited commercial adoption. In this work, an operando isothermal microcalorimetry (IMC) study of a model system containing lithium metal and silicon composite film electrodes was reported on the first two cycles of (de)lithiation. The total heat flow data are analyzed in terms of polarization, entropic, and parasitic heat flow contributions to quantify and determine the onset of parasitic reactions. These parasitic reactions, which include solid−electrolyte interphase formation, contribute to electrochemical irreversibility. To complement the calorimetry, operando X-ray diffraction is used to track the phase evolution of silicon. During cycle 1 lithiation, crystalline Si undergoes transformation to amorphous lithiated silicon and ultimately to crystalline Li 15 Si 4 . The solid-state amorphization process is correlated to a decrease in entropic heat flow, suggesting that heat associated with the amorphization contributes significantly to the entropic heat flow term. This study effectively uses IMC to probe the parasitic reactions that occur during lithiation of a silicon electrode, demonstrating an approach that can be broadly applied to quantify parasitic reactions in other complex systems.
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2021-0182100mtgabs
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2021
detail.hit.zdb_id:
2438749-6
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