1. Q-Carbon : A New Carbon Allotrope with a Low Degree of s-p Orbital Hybridization and Its Nucleation Lithiation Process in Lithium-Ion Batteries
- Author
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Lian, Ruqian, Feng, Jianrui, Chen, Xin, Wang, Dashuai, Kan, Dongxiao, Chen, Gang, Wei, Yingjin, Lian, Ruqian, Feng, Jianrui, Chen, Xin, Wang, Dashuai, Kan, Dongxiao, Chen, Gang, and Wei, Yingjin
- Abstract
A novel metallic carbon allotrope, Q-carbon, was discovered using first-principles calculations. The named Q-carbon possessed a three-dimensional (3D) cage structure formed by carbon atoms with three ligands. The energy distribution of electrons in different orbitals revealed that Q-carbon has a low degree of s-p orbital hybridization. The calculated Li+ binding energies suggested Li+ aggregation inside Q-carbon during lithiation. As a result, a Li8C32 phase was formed and gradually expanded in Q-carbon, implying a typical two-phase transition. This allowed Q-carbon to have a constant theoretical voltage of 0.40 V, which effectively inhibited Li dendrite formation. A stable Li8C32/C-32 two-phase interface was confirmed by stress-strain analysis, and a calculated Li+ diffusion barrier of similar to 0.50 eV ensured effective Li+ diffusion along a 3D pathway. This study was of great significance for the understanding of two-phase transition of Li+ storage materials and provided a new insight into the design of new carbon materials for energy storage applications.
- Published
- 2020
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