Functional Group-Driven Competing Mechanism in Electrochemical Reaction and Adsorption/Desorption Processes toward High-Capacity Aluminum-Porphyrin Batteries

Shuqiang Jiao*, Xue Han*, Li Li Jiang, Xueyan Du, Zheng Huang, Shijie Li, Wei Wang, Mingyong Wang, Yunpeng Liu, Wei Li Song*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

Nonaqueous organic aluminum batteries are considered as promising high-safety energy storage devices due to stable ionic liquid electrolytes and Al metals. However, the stability and capacity of organic positive electrodes are limited by their inherent high solubility and low active organic molecules. To address such issues, here porphyrin compounds with rigid molecular structures present stable and reversible capability in electrochemically storing AlCl2+. Comparison between the porphyrin molecules with electron-donating groups (TPP-EDG) and with electron-withdrawing groups (TPP-EWG) suggests that EDG is responsible for increasing both highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, resulting in decreased redox potentials. On the other hand, EWG is associated with decreasing both HOMO and LUMO energy levels, leading to promoted redox potentials. EDG and EWG play critical roles in regulating electron density of porphyrin π bond and electrochemical energy storage kinetics behavior. The competitive mechanism between electrochemical redox reaction and de/adsorption processes suggests that TPP-OCH3 delivers the highest specific capacity ~171.8 mAh g−1, approaching a record in the organic Al batteries.

Original languageEnglish
Article numbere202410110
JournalAngewandte Chemie - International Edition
Volume63
Issue number39
DOIs
Publication statusPublished - 23 Sept 2024

Keywords

  • electron-donating group
  • electron-withdrawing group
  • Faradaic/Non-Faradaic process
  • Porphyrin
  • redox potential

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