Long‐Life, High‐Rate Rechargeable Lithium Batteries Based on Soluble Bis(2‐pyrimidyl) Disulfide Cathode

• Published in: Angewandte Chemie International Edition Vol. 62; no. 37; pp. e202308561 - n/a
• Main Authors: Xing, Hansong, Guo, Wenlong, Tang, Shuai, Si, Yubing, Song, Jiahan, Fu, Yongzhu
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 11.09.2023
• Edition: International ed. in English
• Subjects: Bis(2-Pyrimidyl) Disulfide; Cathodes; Chemical bonds; Electric vehicles; Electrode materials; Electron transfer; Electrons; Energy of dissociation; Energy storage; Free energy; Heat of formation; High-Rate Cathode; Lithium; Lithium batteries; Lithium-Ion Battery; Molecular orbitals; Organodisulfides; Rechargeable batteries; Storage systems; High-Rate Cathode; Lithium-Ion Battery; Organodisulfides; Bis(2-Pyrimidyl) Disulfide
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202308561

Organosulfides are promising candidates as cathode materials for the development of electric vehicles and energy storage systems due to their low‐cost and high capacity properties. However, they generally suffer from slow kinetics because of the large rearrangement of S−S bonds and structural degradation upon cycling in batteries. In this paper, we reveal that soluble bis(2‐pyrimidyl) disulfide (Pym2S2) can be a high‐rate cathode material for rechargeable lithium batteries. Benefiting from the superdelocalization of pyrimidyl group, the extra electrons prefer to be localized on the π* (pyrimidyl group) than σ* (S−S bond) molecular orbitals initially, generating the anion‐like intermedia of [Pym2S2]2− and thus decreasing the dissociation energy of the S−S bond. It makes the intrinsic energy barrier of dissociative electron transfer depleted, therefore the lithium half cell exhibits 2000 cycles at 5 C. This study provides a distinct pathway for the design of high‐rate, long‐cycle‐life organic cathode materials. Bis(2‐pyrimidyl) disulfide (Pym2S2) has proven to be a high rate cathode material for rechargeable lithium batteries. The superdelocalization of pyrimidyl groups is reducing the S−S bond dissociation energy, which depletes the intrinsic energy barrier of dissociated electron transfer. The lithium half cell achieves 2000 cycles at 5 C. In addition, the cell shows a capacity retention of 78.0 % after 500 cycles at 30 C.