Nanoporous polymer electrolytes for high energy lithium batteries – 2POLI

The safety concern of lithium-ion batteries used conventional liquid electrolyte strengthen more than ever the need to develop safe, powerful and long lifetime batteries. Lithium (Li) metal polymer battery technology is the most attractive one. However, solid polymer electrolyte does not possess neither high ionic conductivity at room temperature nor Li transference number (t+<0,2). However, a high value of t+ (close to one) can prevent the formation of the concentration gradient between the cathode and the anode, responsible for dendritic growth and battery short-circuit. Aside from electrochemical performance, the safety of solid-state batteries is also related to the ionic conductivity of the solid electrolyte. Indeed, ionic conductivity leads to small impedance in the electrolyte and its interfaces with the electrodes and therefore low heat generation during charge/discharge process, particularly at high current densities. In line with those challenges, we propose in the 2POLI project the original nanoporous polymer electrolytes with one dimensional ionic conduction. These nanoporous membranes are derived from nanostructured block copolymers including one sacrificial block. The nanochannels will be perpendicularly oriented to electrodes and filled with nonaqueous lithium electrolytes. Thanks to nano-confinement effects, a quasi-dimensional conduction path and an adequate pore surface chemistry, these materials will exhibit liquid-like ionic conductivity, a t+ close to 1 and moderate flexibility to adapt deformation of the battery without safety concerns.