Grant: CCI Applied Research and Development Grants

Hydro-Québec is currently working on the development of safe, highly efficient, and low-cost solid-state batteries. In this context, Hydro-Québec is looking for new materials for this type of battery and is interested by the phosphorylation process developed at Innofibre. This chemical modification of wood fibers followed by lithium grafting has an interesting potential as a solid electrolyte. Indeed, the adsorption of lithium ions, on phosphate groups grafted at the cellulosic fiber surface, should facilitate the ionic transfer between the anode and the cathode in a battery. From lithiated phosphorylated fibers, membranes (films or sheets) will be produced to get the solid-state electrolyte for incorporation into batteries under development at Hydro-Québec. Depending on fiber size, different production technologies from pulp and paper industry can be used to get the membrane. For each membrane, physicochemical properties (such as elemental composition, thickness, physical resistance) will be characterised in Innofibre’s laboratories, while electrochemical properties (ionic conductivity and lithium displacement) will be characterized by Hydro-Québec. This project will initially focus on the effect of the dimensions of phosphorylated fibers, phosphorylation and lithium grafting parameters and membrane’s production process on the solid electrolyte properties. To do this, several refined cellulosic kraft pulps will be phosphorylated and then lithiated under different conditions. The second part of the study consists in plasticizing several membranes, showing an interesting potential, with solvents currently used in batteries. The addition of lithium salts will also be investigated to increase the ionic conductivity of the membranes. Thereafter, plasticizing will be carried out with a polymer developed by Hydro-Québec (HQ821), in order to multiply the performance of the membranes. Different conditions will be tested to obtain the highest ionic conductivity, with or without the addition of lithiated salts. Finally, the membrane with the best performances and presenting a real possibility of implantation in batteries will be tested in a prototype battery of 1 Ah. For this, Innofibre’s pilot equipment (phosphorylation process, pulp plant, paper machine, surface treatment process) will be used.