St-Onge Vincent, Rochon Sylviane, Daigle Jean-Christophe, Soldera Armand, Claverie Jerome P
Department of Chemistry, Faculty of Sciences, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, QC, J1K 2R1, Canada.
Center of Excellence in Transportation Electrification and Energy Storage, 1804 Lionel-Boulet, 2nd floor, Varennes, QC, J3X 1S1, Canada.
Angew Chem Int Ed Engl. 2021 Dec 1;60(49):25897-25904. doi: 10.1002/anie.202109709. Epub 2021 Nov 2.
The low conductivity of Na electrolytes in solid polymer electrolytes (SPEs) curtails the development of Na polymer batteries. In this study, NaClO (3-24 wt %, 90-9:1 O:Na) is dissolved in statistical copolymers of ethylene oxide (EO) and propylene oxide (PO) (0-20 mol %). Remarkably, the conductivity of these SPEs increases as the concentration of Na decreases, thus departing from the usual Nernstian behavior. Using a combination of calorimetric measurements and molecular dynamic simulations, this unusual phenomenon is attributed to the presence of physical cross-links generated by Na . As a result, polymers containing a low salt concentration (3 wt %) display a drastically enhanced ionic conductivity (up to 0.2 10 S cm at 25 °C), thus paving the way for the design of all-solid-state PEO-based sodium batteries operational at room temperature.
