The demand for lithium-ion batteries (LIBs) is consistently growing due to the expanding market for electric vehicles and portable electronic devices.[1] As a result, it is essential to develop sustainable and safe battery technologies. Binders are key components that interconnect both the active material and the current collector in battery electrodes. Although binders are a low-volume component in batteries, their choice primarily dictates the electrode processing methodology.[2] Poly(vinylidene difluoride) (PVDF) is the most common binder used in LIBs. However, processing PVDF requires organic solvents such as NMP, which is hazardous, teratogenic, and not environmentally friendly. To reduce the environmental impact of LIB production, implementing large-scale aqueous-based processing is of paramount interest.[3],[4]
Herein, we present colloidal nanostructured chitins obtained from fisheries waste as a fluorine-free, sustainable binder for electrode processing in LIBs. This Nano chitin (ChNF) enables aqueous processing of electrodes with minimal binder content and without the need for additional surfactants to disperse hydrophobic electrode materials in water. The electrochemical performance of Gr – Li half-cells and LFP – Gr full-cells were studied with various composition of ChNF and compared with PVDF based electrodes. ChNF-based electrodes demonstrated superior performance compared to PVDF based electrodes (Fig1). Three different ratios of chitin slurries were evaluated, 2, 3, and 4%, among them 4% was performing better and the network forming abilities of these compositions also performed using rheology and 4% has better strength and stability. Additionally, online electrochemical mass spectrometry was used to further understand the impact of binders on gas evolution reactions in LIBs during SEI formation.

References
(1) Grey, C. P.; Hall, D. S. Prospects for Lithium-Ion Batteries and beyond — a 2030 Vision. 2020, 2–5. https://doi.org/10.1038/s41467-020-19991-4.
(2) Bresser, D.; Buchholz, D.; Moretti, A.; Varzi, A.; Passerini, S. Alternative Binders for Sustainable Electrochemical Energy Storage-the Transition to Aqueous Electrode Processing and Bio-Derived Polymers. Energy Environ. Sci. 2018, 11 (11), 3096–3127. https://doi.org/10.1039/c8ee00640g.
(3) Dobryden, I.; Montanari, C. Bio-Based Binder Development for Lithium-Ion Batteries. 2023.
(4) Lingappan, N.; Kong, L.; Pecht, M. The Significance of Aqueous Binders in Lithium-Ion Batteries. Renew. Sustain. Energy Rev. 2021, 147 (May), 111227. https://doi.org/10.1016/j.rser.2021.111227.