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A Generalizable Active-Site Blocking Strategy Enables High Initial Coulombic Efficiency in Mononitrogen-Containing
Wenjun Li1, Yutian Liu1, Yi Fu1
1School of Materials and Energy, University of Electronic Science and Technology of China (UESTC), Chengdu, China.
Angewandte Chemie (International Ed. in English)
|May 7, 2026
Summary
Molecular engineering blocks reactive sites in carbazole-based polymers, enhancing initial coulombic efficiency (ICE) for advanced anion-storage electrodes and enabling stable lithium-based dual-ion batteries.
Area of Science:
- Materials Science
- Electrochemistry
- Organic Chemistry
Background:
- Mononitrogen-containing aromatic compounds like carbazole (CZ) show promise as high-potential p-type anion-storage electrode materials (3.6-4.3 V vs. Li+/Li).
- Their para positions are prone to electropolymerization at potentials above 4 V, causing low initial coulombic efficiency (ICE).
Purpose of the Study:
- To address the challenge of low ICE in carbazole-based electrode materials by developing a molecular engineering strategy.
- To validate the efficacy of active-site blocking through the synthesis and testing of a novel carbazole-based polymer.
Main Methods:
- Molecular engineering of a carbazole-based polymer, poly[5-(9-ethyl-9H-carbazol-3-yl)-5,10-dihydrophenazine] (p-ECZDPZ), by incorporating 5,10-dihydrophenazine and ethyl groups.
- Electrochemical testing of p-ECZDPZ as an electrode material in lithium-based dual-ion full batteries (LDIBs).
- Evaluation of battery performance metrics including initial coulombic efficiency (ICE), discharge capacity, cycle life, and energy density.
Main Results:
- The synthesized p-ECZDPZ demonstrated a superior ICE of 86% without pretreatment, effectively blocking the reactive para positions of the carbazole moieties.
- The constructed LDIBs achieved a peak discharge capacity of 204 mAh g-1, an ICE of 84%, and stable cycling over 20,000 cycles.
- At high cathode mass loading, LDIBs exhibited an energy density of 445 Wh kg-1 with no capacity decay for 8000 cycles, and pouch cells reached 305 Wh kg-1 cathode.
Conclusions:
- Active-site blocking via molecular engineering is an effective strategy to overcome the limitations of carbazole-based electrode materials.
- The developed p-ECZDPZ offers significant improvements in ICE and long-term stability for anion-storage applications.
- This work paves the way for high-performance organic electrode materials in advanced energy storage devices like lithium-based dual-ion batteries.
Keywords:
Li‐based dual‐ion batteriesactive‐site blocking strategyinitial coulombic efficiencylong cycle lifemononitrogen‐containing organic cathodeMore Related Videos
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