Hu Jiahui, Li Lingxiao, Tang Wu, He Xuesong, He Lichuan, Lv Wentao, Zhang Jiahao, Fan Cong
School of Materials and Energy, University of Electronic Science and Technology of China (UESTC), Chengdu, 611731, P. R. China.
ChemSusChem. 2025 Sep 4:e2501151. doi: 10.1002/cssc.202501151.
Perylene-3,4,9,10-tetracarboxylic dianhydride [PTCDA, theoretical specific capacity (C) = 130 mAh g] is an efficient n-type organic cathode in Li-ion batteries with the median potential of ≈2.5 V (vs. Li). In order to improve its working potential, a new insoluble small-molecule organic cathode named 1,7-dicyano-perylene-tetracarboxylic dianhydride (PTCDA-2CN) is designed and synthesized with two electron-withdrawing groups cyano bonds (-CN). As expected, PTCDA-2CN can exhibit the high working potential ≈2.8 V (vs. Li) with its decreased lowest unoccupied molecular orbital energy, which is ≈0.3 V higher than PTCDA. And the introduction of two -CN groups can maintain the basis C value of 121 mAh g for PTCDA-2CN. Consequently, PTCDA-2CN exhibits the good cathode performances in Li-ion half/full cells. In half cells, PTCDA-2CN can show the discharge capacities of 117-107 mAh g with the stable cycling retention of 91% during 100 cycles. Meanwhile, using the reduced state (LiC) of graphite (C) as the anode, the LiC//PTCDA-2CN full cells can also exhibit good performances of 116-98 at 50 mA g with the high median voltage of 2.7 V. PTCDA-2CN is one of the highest potentials ever reported for the n-type organic cathodes in Li-ion batteries.
