Biredox‐Ionic Anthraquinone‐Coupled Ethylviologen Composite Enables Reversible Multielectron Redox Chemistry for Li‐Organic Batteries

Abstract

Organic compounds bearing redox-active ionic pairs as electrode materials for high-performance rechargeable batteries have gained growing attention owing to the properties of synthetic tunability, high theoretical capacity, and low solubility. Herein, an innovative biredox-ionic composite, i.e., ethylviologen dianthraquinone-2-sulfonate (EV-AQ 2 ), affording multiple and reversible active sites as a cathode material in lithium-organic batteries is reported. EV-AQ 2 exhibits a high initial capacity of 199.2 mAh g −1 at 0.1 C rate, which corresponds to the transfer of two electrons from one redox couple EV 2+ /EV 0 and four electrons from two redox-active AQ − anions. It is notable that EV-AQ 2 shows remarkably improved cyclability compared to the precursors. The capacity retention is 89% and the Coulombic efficiency approaches 100% over 120 cycles at 0.5 C rate. The results offer evidence that AQ − into the EV 2+ scaffold with multiple redox sites are promising in developing high-energy-density organic rechargeable batteries.

Sulfur‐containing polymer cathode materials: From energy storage mechanism to energy density

“…These special organic groups are beneficial for average cell voltage and specific energies enhancement. Sulfur‐containing polymers with multiple SS bonds can significantly realize the purpose of multi‐electron transportation 84 during lithiation process. According to Nernst equation, the number of electrons transfer is directly proportional to the energy density of batteries.…”

Trinitroaromatic Salts as High-Energy-Density Organic Cathode Materials for Li-Ion Batteries

“…(c) Comparison of the performance of C 6 H 2 (NO 2 ) 3 OK with reported inorganic (1–5)/organic (6–14) electrode materials in terms of specific capacity and voltage. Cathodes for comparison (ref): 1,LiMn 2 O 4 2,LiCoO 2 3,LiFePO 4 4,NCA 5,Li-rich 6,EV-AQ 2 7,Fe­(DHBQ) 3 8,PTO 9,3Q 10,Cu-THQ 11,C 4 Q 12,C 6 Q 13, m -DNB 14,C 6 O 6 (d) MSD of Li 6 [C 6 H 2 (NO 2 ) 3 OK].…”

Boosting the zinc storage of a small-molecule organic cathode by a desalinization strategy

“…Various approaches have been explored to improve battery performance, including polymerization and salinization. 44,45 Nonetheless, it is essential to note that polymers with dense structures can reduce the number of electroactive sites and hinder ion transportation, resulting in a reduced capacity, as well as poor cycling stability and rate capability. Thus, designing a suitable molecular structure that overcomes the limitations associated with polymers while effectively addressing solubility and conductivity concerns and preserving the electrochemical activity of the material remains a significant challenge.…”