A Macromolecule Cathode for High-Performance Li-Ion and Na-Ion Batteries

Organic macromolecules have a molecular weight (Mw) between small molecules (Mw < 1000 g mol–1) and polymers (Mw > 5000 g mol–1). In this work, we design a novel organic macromolecule, namely, 1,1′-(1,4-phenylene)-bis[N,N′-bis(2-anthraquinone)]-bis[perylene-3,4,9,10-tetracarboxydiimide] (2PTCDI-4AQ). 2PTCDI-4AQ has a definite molecule structure and a large Mw value of 1679.59 g mol–1, thus showing good insolubility against most organic liquids. Meanwhile, 2PTCDI-4AQ can deliver a 12-electron redox mechanism and a theoretical specific capacity (CT) of 189 mAh g–1. Consequently, 2PTCDI-4AQ exhibits high cathode performances in Li-ion and Na-ion half/full cells. For instance, 2PTCDI-4AQ can show the discharge capacities of 174–188 mAh g–1 with a highly stable cycling retention of 93–97% during 100 cycles. Meanwhile, 2PTCDI-4AQ can also exhibit good rate performances of 130–148 mAh g–1 at the large current of 5 A g–1. As far as we know, this is the first example of macromolecule organic electrodes reported in Li-ion and Na-ion batteries.