Conjugated Microporous Polymers with Bipolar and Double Redox-Active Centers for High-Performance Dual-Ion, Organic Symmetric Battery

Redox-active conjugated microporous polymers (RCMPs) have received remarkable interest in electrochemical energy-storage systems in view of their porous structure and tunable redox nature. This work presents an effective strategy to construct RCMPs with bipolar and double redox-active centers by integrating copper (II) tetraaminephthalocyanine (CuTAPc) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) units into the RCMPs (CuPcNA-CMP). As expected, CuPcNA-CMP has potential application in the half cells of dual-ion batteries (lithium based DIBs, LDIBs), asymmetric DIBs (graphite based DIBs, ADIBs), and symmetric DIBs (all organic DIBs, SDIBs). Among them, LDIBs show a high reversible capacity (202.4 mAh g(-1) at 0.2 A g(-1)) and excellent rate capability (86.1 mAh g(-1) at 5 A g(-1)). And ADIBs also show a high reversible capacity (245.3 mAh g(-1) at 0.1 A g(-1)), long cycle stability with capacity retention of 89% after 500 cycles, and good rate performance (125.1 mAh g(-1) at 5 A g(-1)). In addition, SDIBs show high initial charge/discharge capacities of 269.4/198.5 mAh g(-1) at 0.05 A g(-1) and a high cell voltage of 2.5 V. Meanwhile, the mechanism of CuPcNA-CMP on hosting both anions (PF6-) and cations (Li+) is investigated by detailed experimental analysis and density functional theory studies.

Automated summary

This study successfully constructed CuPcNA-CMP with bipolar and double redox-active centers, showing good reversible capacity, cycle stability, and rate performance in various types of dual-ion batteries.