Green processing of electrode materials using Na-CMC as binder within SIRBATT project

One of the most relevant challenges in the Li-ion battery research is the development of green processes in order to reduce the environmental impact of materials and manufacturing processes. In this context a key role is certainly the study and optimization of eco-friendly binder. Among them, one of the most interesting is the sodium salt of carboxymethyl cellulose (Na-CMC) . This aqueous green binder has been used in SIRBATT project to prepare and optimize CMC-based electrodes in order to investigate its effect on the stability of interface and, at the same time, to find the formulation that allows the best electrochemical performances through a preliminary characterization in lab-scale half-cells. The materials investigated are: (a) graphite, (b) ZnFe2O4 (ZFO), (c) Li4Ti5O12 (LTO) as anodes; (d) LiFePO4 (LFP), (e) LiMn2O4 (LMO) as cathodes. Each electrode has been prepared by casting the slurry containing active material, SuperC65 and CMC in ultrapure H2O.The preliminary characterization of the electrode performances for each material has been carried out by using constant current-constant potential (CC-CV) protocol at two different C-rate values. The results have shown that the cycling performances of electrodes are comparable with PVdF-based electrodes, therefore the PVDF substitution by CMC has been confirmed as a viable option towards the production of “greener” electrodes without performance loss. Furthermore, since the performances of materials strongly depends on the stability of the interfaces, impedance measurements are carried out. Preliminary results reveal an improved, more stable electrode/electrolyte interface.