Bridging Energy and Power Density Gap: Multi-Redox CMP/CNT Composite as High Loading Organic Cathode for Lithium-Ion...

Conjugated microporous polymers (CMPs) have emerged as promising materials for energy storage devices, including lithium-ion batteries (LIBs), owing to their high surface area, chemical tunability, eco-friendliness, and fast redox kinetics. However, their practical applications are limited by poor conductivity, low active material utilization, lower redox potential and cycling degradation, which hampers their utilization for LIBs. Herein, we report the synthesis of dihydrophenazine based CMP (TPA-DPZ) with multi-redox centers and its composite with acid functionalized CNTs equal to only 5% of CNTs by total wt.% of monomers using in situ polymerization technique (TPA-DPZ@CNT 5%). The fabricated cathode with high active material loading of 80% with an average discharge potential of 3.39 V achieved a maximum specific capacity of 128 mAh g^-1. Remarkably, at a higher current density of 20 A g^-1, it retains a capacity of 68.34 mAh g^-1 with a discharge time of only 13 s. The electrode exhibits excellent long-term stability, retaining 89% of its initial capacity after 10 000 cycles. It possessed a high energy density of 445 Wh kg^-1 (at 0.1 A g^-1) combined with a high power density of 67 kW kg^-1 at 20 A g^-1. This work highlights the synergistic effect of multi-redox CMP and conductive CNTs in overcoming the limitations of organic electrodes.