Long-lifespan Polyanionic Organic Cathodes for Highly Efficient Organic Sodium-ion Batteries

Graphical Go Organic ! A long-lifespan small-molecule organic sodium-ion battery is described. The battery is constructed using a 9,10-anthraquinone-2,6-disulfonate (Na 2 AQ26DS) cathode and sodium terephthalate (Na 2 TP) anode, and delivers a maximum discharge capacity of 131 mAh g −1 cathode in 0.5–3.2 V, maintaining an average value of approximately 62 mAh g −1 cathode over 1200 cycles (0.5 A g −1 , ≈4 C). An organic Na-ion battery is reported with a polyanionic 9,10-anthraquinone-2,6-disulfonate (Na 2 AQ26DS, 130 mAh g −1 ) cathode and the Na-intercalated state (Na 4 TP) of sodium terephthalate (Na 2 TP, 255 mAh g −1 ) as the anode. The resulting full cells deliver the maximum discharge capacity of 131 mAh g −1 cathode in 0.5–3.2 V, simultaneously maintaining the average value of ≈62 mAh g −1 cathode during 1200 cycles (0.5 A g −1 , ≈4 C). These results are among the best performing organic sodium-ion full cells reported to date.