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

Abstract

Organic macromolecules have a molecular weight (M w ) between small molecules (M w < 1000 g mol −1 ) and polymers (M w > 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 M w 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 (C T ) 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.