Toward Greener and Sustainable Li-Ion Cells: An Overview of Aqueous-Based Binder Systems

Abstract

Lithium ion (Li-ion) cells have gained considerable attention in the past few years as one of the most promising energy storage systems for various applications. Binders, an important component of Li-ion cells, have a crucial effect on the performance of the cells. Considerable efforts have been made recently for the development of cost-effective and environmentally friendly water-based binders for Li-ion cells. However, detailed insight of the aqueous-based binders pertaining to the electrode materials exclusively for Li-ion cells has not been reported yet. This Perspective covers the research and development to date on various classes of organic, polymer-based aqueous binders for various anode and cathode materials, which allows for the replacement of toxic and costly N-methyl-2-pyrrolidone and presents a detailed comparative study of various aqueous binders. The effect of various aqueous binders on different electrode-active materials, especially on electrodes under current development, is also discussed. Furthermore, the impact of the binding agents and the related chemical reactions on the morphology of the electrode, specific capacity, and cycle life is reviewed. This Perspective will surely aid the readers to easily identify and study appropriate aqueous binders for electrode-active materials of their interest.

Polymer Binders: Characterization and Development toward Aqueous Electrode Fabrication for Sustainability

“…Water is an inexpensive solvent, especially compared to NMP (around 0.015 $/kg for water versus 1–3 $/kg for NMP [ 65 ]); these savings add together with the frequently lower cost for commonly used aqueous binders, which often range from 2 to 5 $/kg. Furthermore, using water greatly reduces the environmental impact of electrode fabrication by replacing the use of NMP; as added benefits, this also lowers the emission of CO 2 equivalents and further reduces fabrication costs, as costly solvent recovery is not required [ 7 , 65 , 67 ]. Water also has a significantly lower boiling point than NMP, which can speed up evaporation during fabrication.…”

“…Due to water’s low cost and environmental friendliness, there has been a movement toward the safer and more sustainable fabrication of energy storage devices using aqueous dispersions. One conventional aqueous binder is poly(tetrafluoroethylene) (PTFE), which is applied as an emulsion in water, and it is used either directly or in its sulfonated ionomer form, Nafion [ 67 , 70 ]. While not often utilized for battery electrodes, it is more commonly used to bind high surface area materials in supercapacitors [ 56 , 71 , 72 ].…”

Advances of polymer binders for silicon‐based anodes in high energy density lithium‐ion batteries

“…In fact, compared with the complicated and high-cost nanostructure or hierarchical fabrication of Si-based materials, developing high-performance polymer binders for Si-based anodes, especially the low-cost, safe, and environmentally friendly aqueous binders, also represents a cost-effective approach to improve the cycling performance of Si-based anodes. 30,48,49 To date, an increasing number of polymer binders, with characteristics like high elasticity, strong adhesive, self-healing, ionic or electronic conductivity, and so forth, have been developed for various Si-based anodes. All these explorations provide a variety of very helpful instructions for designing of advanced polymer binders to promote the practical application of Si-based anodes.…”

Application of Guar Gum and its Derivatives as Green Binder/Separator for Advanced Lithium‐Ion Batteries

“…To overcome these challenges, several strategies have been investigated for example novel architechture of electrodes, functional separator, nano‐scale active materials. Furthermore, synthetic and natural compound‐based binders have also been incorporated with the electrodes [37–55] …”

“…Furthermore, synthetic and natural compound-based binders have also been incorporated with the electrodes. [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] The binders are essential component for the fabrication of LIBs. The passive binders generally improve inter-connectivity within the electrodes (active material, current collector, conductivity enhancer) and, also facilitates ionic conductivity.…”