Chengdu Green Energy and Green Manufacturing Technology R&D Center, Chengdu, Sichuan, 610207, China.
University of Electronic Science and Technology of China, Sichuan, 610054, China.
Sci Rep. 2016 Nov 29;6:37911. doi: 10.1038/srep37911.
Systematic first-principles calculations were performed to investigate the adsorption and diffusion of Li on different graphene layers with B/N-doping and/or C-vacancy, so as to understand why doping heteroatoms in graphene anode could significantly improve the performance of lithium-ion batteries. We found that the formation of single or double carbon vacancies in graphene are critical for the adsorption of Li atoms. While the N-doping facilitates the formation of vacancies, it introduces over binding issue and hinders the Li diffusion. The presence of B takes the excessive electrons from Li and N and reduces the energy barrier of Li diffusion on substrates. We perceive that these clear insights are crucial for the further development of graphene based anode materials for lithium-ion batteries.
采用第一性原理系统计算研究了 Li 在具有 B/N 掺杂和/或 C 空位的不同石墨烯层上的吸附和扩散，以了解为什么在石墨烯阳极中掺杂杂原子可以显著提高锂离子电池的性能。我们发现，在石墨烯中形成单个或双碳空位对于 Li 原子的吸附至关重要。虽然 N 掺杂有利于空位的形成，但它会导致过度结合问题并阻碍 Li 的扩散。B 的存在从 Li 和 N 中获取过量电子，并降低 Li 在基底上扩散的能垒。我们认为，这些清晰的见解对于进一步开发基于石墨烯的锂离子电池阳极材料至关重要。
