The European and world interest in the research topics in electrochemical energy storage is increasingly oriented not only to the improvement of lithium ion (LiB) batteries in terms of safety and efficiency, but also towards the development of new chemistries such as, for example, sodium ion batteries (NIB). In the specific field of NIB, the RSE focused its research on cathode materials with high/medium potential and with a theoretical capacity equal to or greater than 100 mAh/g.
The central point of the research was the production of cathode materials free of toxic elements such as cobalt and nickel,which are also included in the list of critical raw materials recently drawn up by the EC.

We focused on two materials, an oxide with layered structure (Na0.66MnO2) and a phosphate with NASICON structure (Na3MnTi(PO4)3). Na0.67MnO2 has shown high specific capacity values, close to the theoretical one for low current values and higher than 130 mAh/g for current values coresponding to 1C, also maintaining an average working potential equal to 3 V vs Na/Na+ even in long galvanostatic cycles. NASICON showed excellent stability in galvanostatic cycles exceeding 100 cycles, but in terms of capacity, values lower than the desired objectives were obtained.

Non-flammable electrolytes with a wide range of potential stability (from zero to 4.7 V vs NA/Na+) have been also studied, investigating their coupling with the layered material. and with the anode material, also developed by RSE, with which it is intended to create a complete single cell.

The Report is available on the Italian site