Design of High-density Carbonyl-Functionalized Perylenetetracarboxylic-based Conjugated Microporous Polymers for Enhanced Lithium Storage Performance

Perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) shows promise as an organic electrode material for lithium–ion batteries, but its dissolution in organic electrolytes severely limits practical application. To address this, this study designed and synthesized two PTCDA-based conjugated microporous polymers (TAPB-PTCDA and PBAPD-PTCDA), aiming to suppress dissolution through polymerization while simultaneously increasing the density of electroactive carbonyl groups to enhance lithium storage performance. These materials were constructed using PTCDA as the electroactive center, coupled via C–N bonds with triamine (TAPB) and tetraamine (PBAPD) linkers, respectively. Structural characterization confirmed the successful synthesis of the target polymers, which exhibited excellent thermal stability (retaining approximately 80% of their mass up to 550 °C) and abundant microporous structures. Electrochemical tests revealed that PBAPD-PTCDA, with its higher carbonyl density and larger conjugated framework, delivered superior performance compared to TAPB-PTCDA. After 400 cycles at a current density of 0.5 A g –1, PBAPD-PTCDA maintained a high reversible specific capacity of 268.6 mA h g –1, significantly surpassing the 222.2 mA h g –1 of TAPB-PTCDA. This study demonstrates that increasing the density of electroactive carbonyl groups in conjugated microporous polymers through molecular design is an effective strategy for improving the lithium storage performance of organic electrode materials.