Anthraquinone‐Based Oligomer as a Long Cycle‐Life Organic Electrode Material for Use in Rechargeable Batteries. Issue 7 (7th March 2019)

• Record Type: Journal Article
• Authors: Yao, Masaru; Sano, Hikaru; Ando, Hisanori; Kiyobayashi, Tetsu; Takeichi, Nobuhiko
• Is Part Of: Chemphyschem. Volume 20:Issue 7(2019)
• Page Start: 967
• Page End: 971
• Publication Date: 2019-03-07
• Subjects: lithium ion battery -- long cycle-life -- oligomerization -- organic cathode -- pi-stack interactions; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201900012
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: An anthraquinone (AQ)‐based dimer and trimer linked by a triple bond (−C≡C−) were newly synthesized as active materials for the positive electrode of rechargeable lithium batteries. These synthesized oligomers exhibited an initial discharge capacity of about 200 mAh g −1 with an average voltage of 2.2–2.3 V versus Li(C.E.) . These capacity values are similar to that of the AQ‐monomer, reflecting the two‐electron transfer redox per AQ unit. Regarding their cycling stability, the capacity of the monomer electrode quickly decreased; however, the electrodes of the prepared oligomers showed an improved cycling performance. In particular, the discharge capacities of the trimer remained almost constant for 100 cycles. A theoretical calculation revealed that the intermolecular binding energy can be increased to the level of a weak covalent bonding by oligomerization, which would be beneficial to suppress the dissolution of the organic active materials into the electrolyte solutions. These results show that the cycle‐life of organic active materials can be extended without lowering the discharge capacity by the oligomerization of the redox active molecule unit. Abstract : Durable oligomer : The cycle‐life of organic active materials was found to be extended by oligomerization. The capacity of the electrode using the anthraquinone monomer quickly decreased, whereas the ones of its oligomers showed a longer cycle‐life. Theoretical calculations indicate that the intermolecular binding energy is increased to the level of covalent bonding by oligomerization, which would be beneficial to overcome the dissolution problem during cycling.