An all-solid state NASICON sodium battery operating at 200 degree C

An all-solid state symmetric monolithic sodium ion battery operating at 200 degree C is described, using NASICON-type electrodes and electrolyte. Na3V2(PO4)3 is used at both electrodes as the active material while Na3Zr2Si2PO12 stands the role of the Na+ solid electrolyte. Both compositions present order-disorder phase transitions and present decent ionic conductivity properties, 1.5 10-3 S cm-1 and 1.9 10-4 S cm-1 at 200 degree C for Na3Zr2Si2PO12 and Na3V2(PO4)3, respectively. The full battery (560 mu m in thickness) was assembled in a 10' single step by spark plasma sintering at 900 degree C. The electrochemical characteristics at high temperature (200 degree C) were evaluated thanks to a new experimental set-up. The battery operates at 1.8 V with 85% of the theoretical capacity attained at C/10 with satisfactory capacity retention, for an overall energy density of 1.87 10-3 W h cm-2 and a capacity of 1.04 mA h cm-2.