Extended cycle life in lithium-ion batteries through lithium supplementation from Li$_2$C$_4$O$_4$@SiO$_2$ microcapsules

Pal, Bhupender (author), Jurečič, Luka (author), Gabrijelčič, Matej (author), Dominko, Robert (author)

The formation of a solid electrolyte interphase (SEI) in lithium-ion batteries consumes active lithium ions, resulting in loss of capacity and decreased cycle life. Most prelithiation methods only address the initial lithium depletion by compensating with a source of lithium ions, overlooking the ongoing lithium consumption through continuous degradation processes. In this study, Li$_2$C$_4$O$_4$@SiO$_2$ microcapsules are presented, in which Li$_2$C$_4$O$_4$ serves as an additional source of lithium ions and the porous SiO$_2$ shell prevents unwanted catalytic reactions, ensuring sustained lithium availability throughout the cycling. The microcapsules are synthesized using a wet impregnation method and characterized using various techniques to confirm their structural, morphological, and compositional properties. Ex situ nuclear magnetic resonance (NMR) analysis demonstrated lithium-ion mobility, and electrochemical tests in full-cell configurations with graphite and graphite/silicon anodes confirmed improved capacity retention and cycle life. This work highlights the potential of microencapsulated lithium-ion sources to improve battery performance in various lithium-ion systems and opens a pathway for battery cells with self-healing functionality that can be triggered on demand.

• Language: English
• Keywords: lithium-ion battery, microcapsules, ex-situ NMR, cathode additive, degradation, dilithium squarate, Li-ion batteries, lithiation additive, self-healing
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 9 str.
• Numbering: Vol. 9, iss. 1, art. e202500444
• PID: 20.500.12556/RUL-172577
• UDC: 621.352
• ISSN on article: 2566-6223
• DOI: 10.1002/batt.202500444
• COBISS.SI-ID: 247147011
• Publication date in RUL: 09.09.2025

Record is a part of a journal

• Title: Batteries & supercaps
• Publisher: Wiley, Chemistry Europe
• ISSN: 2566-6223
• COBISS.SI-ID: 30750979

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: litij-ionski akumulator, mikrokapsule, ex-situ jedrska magnetna resonanca