In the manufacturing process of lithium-ion batteries, the current organic solvent-based processes will inevitably be replaced with eco-friendly water-based processes. For this purpose, the current organic-soluble binder should be replaced with a water-soluble or water-dispersed binder. In this study, a new polyacrylate latex dispersed in water was successfully applied as a binder of lithium-ion battery cathodes for the first time. One of the biggest advantages of the polyacrylate binder is that it is electrochemically stable at the working voltage of typical cathodes, unlike a conventional water-dispersed styrene-butadiene binder. This implies that the water-dispersed polyacrylate has no limitations for the usage of a cathodic binder. The performance of the polyacrylate binder for lithium iron phosphate cathodes was compared with those of a conventional organic-based polyvinylidene fluoride binder as well as a water-dispersed styrene-butadiene binder. The polyacrylate binder exhibited an electrochemical performance that was comparable to that of an existing styrene-butadiene binder and much better than that of the polyvinylidene fluoride binder. This superior performance of the polyacrylate binder is attributed to the point-to-point bonding mechanism of an emulsified binder, which leads to a strong adhesion strength as well as the low electrical and charge transfer resistances of the cathodes.

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In recent years, water-based binders have been attracted for electrochemical double-layer capacitor (EDLC) due to their eco-friendly and easy manufacture processing, such as: carboxymethyl cellulose (CMC), Styrene Butadiene Rubber (SBR), poly tetrafluoroethylene (PTFE), etc. Particularly, the combination of CMC and SBR shows better performance than polyvinylidene fluoride (PVdF) which is dissolved in a harmful organic solvent, N-methyl-2-pyrollidone (NMP). Good ionic/electronic conduction of binder can greatly improve the performance of electrode, even though the key factor of binder materials is electrode adhesion. Recently, a new type of two-dimensional material composed of transition metal carbides or nitrides was developed, which is highly electronically conductive. In our research, we synthesized a high adhesive poly(acrylonitrile-co-butylacrylate) on the surface of the two-dimensional conductive materials by emulsion polymerization. This novel conductive water-based binder was applied to EDLC and have a remarkable effect on the electrochemical performance. A variety of characteritics demonstrate that the polymer binder containing 2-dimentional conducting materials can be a good candidate binder for EDLCs, probably lithium ion batteries.