Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries

The occurrence of Coulombic efficiency (CE) troughs in silicon (Si) anodes for lithium‐ion batteries (LIBs) presents a critical yet overlooked concern that can lead to battery failure in full cells. Herein, a comprehensive investigation into this previously unreported phenomenon is conducted. Factor...

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Main Authors: Asif Latief Bhat, Yu‐Sheng Su
Format: Article
Language:English
Published: Wiley-VCH 2025-07-01
Series:Small Science
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Online Access:https://doi.org/10.1002/smsc.202500131
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author Asif Latief Bhat
Yu‐Sheng Su
author_facet Asif Latief Bhat
Yu‐Sheng Su
author_sort Asif Latief Bhat
collection DOAJ
description The occurrence of Coulombic efficiency (CE) troughs in silicon (Si) anodes for lithium‐ion batteries (LIBs) presents a critical yet overlooked concern that can lead to battery failure in full cells. Herein, a comprehensive investigation into this previously unreported phenomenon is conducted. Factors influencing CE trough occurrence and severity, including electrode thickness, Si particle size, cycling rate, electrolyte composition, and voltage window, are systematically examined. Experimental results demonstrate that thinner electrodes and slower cycling rates accelerate CE trough onset, whereas employing a tetrahydrofuran (THF)‐based electrolyte or a narrower voltage window (0.01–0.5 V) results in stable electrochemical performance without CE troughs, concurrently with the presence of LixSi. Structural analysis via high‐angle annular dark‐field scanning transmission electron microscopy and scanning electron microscopy reveals a close association between CE trough severity, electrode volume expansion, and delamination, influenced by the formation of a sponge‐like structure and solid electrolyte interface (SEI) stability. These findings yield valuable insights into CE trough mechanisms and provide guidance for mitigating their occurrence through electrode design, electrolyte selection, and operational parameters, thereby advancing high‐performance LIB development. Future research directions involve exploring the role of SEI components and alternative electrolyte additives to enhance SEI stability and mitigate CE troughs.
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spelling doaj-art-869f8870e4c240118f37ee367a687b2b2025-08-20T03:17:28ZengWiley-VCHSmall Science2688-40462025-07-0157n/an/a10.1002/smsc.202500131Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion BatteriesAsif Latief Bhat0Yu‐Sheng Su1International College of Semiconductor Technology National Yang Ming Chiao Tung University 1001 Daxue Road Hsinchu 300093 TaiwanInternational College of Semiconductor Technology National Yang Ming Chiao Tung University 1001 Daxue Road Hsinchu 300093 TaiwanThe occurrence of Coulombic efficiency (CE) troughs in silicon (Si) anodes for lithium‐ion batteries (LIBs) presents a critical yet overlooked concern that can lead to battery failure in full cells. Herein, a comprehensive investigation into this previously unreported phenomenon is conducted. Factors influencing CE trough occurrence and severity, including electrode thickness, Si particle size, cycling rate, electrolyte composition, and voltage window, are systematically examined. Experimental results demonstrate that thinner electrodes and slower cycling rates accelerate CE trough onset, whereas employing a tetrahydrofuran (THF)‐based electrolyte or a narrower voltage window (0.01–0.5 V) results in stable electrochemical performance without CE troughs, concurrently with the presence of LixSi. Structural analysis via high‐angle annular dark‐field scanning transmission electron microscopy and scanning electron microscopy reveals a close association between CE trough severity, electrode volume expansion, and delamination, influenced by the formation of a sponge‐like structure and solid electrolyte interface (SEI) stability. These findings yield valuable insights into CE trough mechanisms and provide guidance for mitigating their occurrence through electrode design, electrolyte selection, and operational parameters, thereby advancing high‐performance LIB development. Future research directions involve exploring the role of SEI components and alternative electrolyte additives to enhance SEI stability and mitigate CE troughs.https://doi.org/10.1002/smsc.202500131fluoroethylene carbonateirreversible losssponge structuretetrahydrofuranvoltage windowsvolume changes
spellingShingle Asif Latief Bhat
Yu‐Sheng Su
Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
Small Science
fluoroethylene carbonate
irreversible loss
sponge structure
tetrahydrofuran
voltage windows
volume changes
title Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
title_full Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
title_fullStr Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
title_full_unstemmed Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
title_short Unraveling the Coulombic Efficiency Trough of Silicon Anodes in Li‐Ion Batteries
title_sort unraveling the coulombic efficiency trough of silicon anodes in li ion batteries
topic fluoroethylene carbonate
irreversible loss
sponge structure
tetrahydrofuran
voltage windows
volume changes
url https://doi.org/10.1002/smsc.202500131
work_keys_str_mv AT asiflatiefbhat unravelingthecoulombicefficiencytroughofsiliconanodesinliionbatteries
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