Sodium ion batteries (NIB) represent nowadays one of the most promising « beyond Li » technologies. However, and according to recent reviews [1], the development of a true market based on NIB strongly depends on optimizing positive/negative electrode couples delivering high potentials and with a suitable electrolyte.

Research carried out in the PCM2E/GREMAN laboratories is focused on the synthesis and electrochemical characterization of positive electrodes based on new materials ascribed to the Na-rich oxide family, not containing expensive and toxic ions as cobalt.  In a first time, sodium half-cells with very nice capacities, close to 140 mAh/g, have been successfully prepared in our laboratories. In order to ensure capacity retention, we have also studied different electrolytes by measuring their impact on the electrode/electrolyte interphase. Spectroscopic techniques as XPS and EIS are helpful for this goal. More recently, our laboratories are focusing on the building of full cells containing such oxides against optimized hard carbon-based composites as negative electrode, with increased conductivity.

In this presentation we will show the first results on these full NIBs and analyze their cycling properties by the use of different physico-chemical and electrochemical techniques.

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