A polyimide based all-organic sodium ion battery†
Developing new approaches to improve the performance of organic electrodes for rechargeable sodium batteries is important. Here, we report studies on N,N′-diamino-3,4,9,10-perylenetetracarboxylic polyimide (PI) as a novel cathode for a sodium battery and demonstrate an all-organic sodium ion battery using this polyimide as the cathode and disodium terephthalate (NaTP) (pre-sodiated) as the anode. The synthesised PI exhibits excellent electrochemical properties, when studied as the cathode for sodium batteries, with a reversible capacity of 126 mA h g−1 along with good capacity retention and rate capability, in the voltage range of 1.5 to 3.5 V vs. Na+/Na. The all-organic sodium ion full cell delivered an initial capacity of 73 mA h g−1, with an average cell voltage of 1.35 V. The attractive electrochemical performance combined with the design flexibility of a PTCDA based PI material, offer new possibilities for the development of efficient all-organic sodium ion batteries.