A Quinone Anode for Lithium‐Ion Batteries in Mild Aqueous Electrolytes. Issue 9 (12th March 2020)

• Record Type: Journal Article
• Authors: Jing, Yan; Liang, Yanliang; Gheytani, Saman; Yao, Yan
• Is Part Of: ChemSusChem. Volume 13:Issue 9(2020)
• Page Start: 2250
• Page End: 2255
• Publication Date: 2020-03-12
• Subjects: aqueous batteries -- Li-ion batteries -- pKa -- protons -- quinones; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202000094
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Aqueous batteries could be potentially used for grid‐scale energy storage owing to the use of nonflammable electrolytes and long cycle life. Recently, quinones have shown examples as redox‐active materials in aqueous batteries under either strong acidic or basic conditions. However, a quinone‐based battery with a less corrosive electrolyte is still rare. Given that quinone‐based batteries are heavily influenced by the pH of electrolytes, we studied the influence of acid dissociation constants (p K a) of hydroquinones on their performance as solid electrode materials. We measured the p K a of anthracene‐9, 10‐diol (AQH2 ) and benzo[1, 2‐b:4, 5‐b′]dithiophene‐4, 8‐diol (BDTDH2 ) from the Pourbaix diagrams of two para ‐quinone monomers [i.e., anthracene‐9, 10‐dione (AQ) and benzo[1, 2‐b:4, 5‐b′]dithiophene‐4, 8‐dione (BDTD)]. Subsequently, their polymeric forms [i.e., poly(anthraquinonyl sulfide) (PAQS) and poly(benzo[1, 2‐b:4, 5‐b′]dithiophene‐4, 8‐dione‐2, 6‐diyl sulfide) (PBDTDS)] were investigated as electrodes in aqueous lithium‐ion cells. At pH 13, PAQS demonstrates a low capacity and poor cycle life, whereas PBDTDS shows a capacity of 196 mAh g −1 and fade rates of 0.0038 % per cycle over 4200 cycles, 0.77 % per day over 21 days. The differences in capacity and cycle stability can be explained by the difference of corresponding p K a values. A full cell with the configuration of (−)PBDTDS|2.5 m Li2 SO4 (pH 13)|LiCoO2 (+) shows a voltage of 1.08 V, a capacity of 72 mAh g −1 and ≈99.9 % of Coulombic efficiency for 500 stable cycles. Abstract : pKa dependent capacity : Given that quinone‐based batteries are heavily influenced by the pH of electrolytes, we studied the influence of acid dissociation constants (p K a) of hydroquinones on their performance as electrode materials for aqueous lithium‐ion batteries. At pH 13, poly(anthraquinonyl sulfide) demonstrates a low capacity and poor cycle life, whereas poly(benzo[1, 2‐b:4, 5‐b′]dithiophene‐4, 8‐dione‐2, 6‐diyl sulfide) demonstrates a capacity of 196 mAh g −1 and fade rates of 0.0038 % per cycle over 4200 cycles, 0.77 % per day over 21 days; the differences in capacity and cycle stability can be explained by the difference of corresponding p K a values.