Melt-processed electrode for lithium ion battery

With the advent of electric vehicles and the growing need for energy storage systems, the development of Li-ion batteries that are capable of increased GWh production is anticipated in the coming years. Thus, it is essential to develop new Li-ion battery manufacturing processes that are both environmentally sustainable and cost effective. In this regard, an original roll-to-roll industrial process was developed to manufacture composite Li-ion battery electrodes. This process consists of replacing the classical technique of dissolving polyvinylidene fluoride (PVdF) binder in an expensive and toxic solvent (typically N-methyl pyrrolidone) with a solvent-free process. In this study, the authors present a unique hot melt extrusion process which consists of mixing a polymer processing aid (PPA) and an elastomeric binder (hydrogenated nitrile butadiene rubber (HNBR)) to decrease the viscosity of the mixture and gain precise control on porosity in the resultant composite electrodes. The versatility of this process would make it easily adaptable to various active materials. In this work, the authors present each step of this unique process converting raw materials to porous composite electrodes. The competitive electrochemical performances of the composite electrodes are assessed using half-cell configurations, whereas power performances are measured using LiFePO4–Li4Ti5O12 full cells.