arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.12912cond-mat.mtrl-sci
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掺杂石墨烯作为Li-O2和Na-O2电池阴极催化剂的理论分析--计算方案的影响

Theoretical analysis of doped graphene as cathode catalyst in Li-O2 and Na-O2 batteries -- the impact of the computational scheme

Katarina A. Novčić, Ana S. Dobrota, Milena Petković, Börje Johansson, Natalia V. Skorodumova, Slavko V. Mentus, Igor A. Pašti

摘要:

了解M-O2电池(M = Li或Na)中的反应对于进一步发展这一有前途的技术具有重要意义。在这方面,计算建模可能会有所帮助,但需要一种适当的方法来建模这样的复杂系统。我们提出了一个新的方案,在M-O2电池,其中参考能量从高层次理论,CCSD(T),而反应中间体与催化剂表面的相互作用提取计算成本较低的DFT的建模过程。该方法被证明的情况下,石墨烯为基础的表面作为模型催化剂在锂-O2和钠-O2电池使用最小可行的机制。B掺杂的石墨烯被认为是所考虑的表面中最好的催化剂,而原始石墨烯表现不佳。此外,我们表明,包括DFT的分散校正计算的放电和充电电位有显着的影响,并建议,长程分散相互作用时,石墨烯为基础的材料建模为电催化剂应始终被考虑。最后,我们提供了一般的指导原则,设计新的ORR催化剂的M-O2电池的催化剂表面的相互作用的优化与反应中间体。

英文摘要:

Understanding the reactions in M-O2 cells (M = Li or Na) is of great importance for further advancement of this promising technology. Computational modelling can be helpful along this way, but an adequate approach is needed to model such complex systems. We propose a new scheme for modelling processes in M-O2 cells, where reference energies are obtained from high-level theory, CCSD(T), while the interactions of reaction intermediates with catalyst surfaces are extracted from computationally less expensive DFT. The approach is demonstrated for the case of graphene-based surfaces as model catalysts in Li-O2 and Na-O2 cells using the minimum viable mechanism. B-doped graphene was identified as the best catalyst among considered surfaces, while pristine graphene performs poorly. Moreover, we show that the inclusion of dispersion corrections for DFT has a significant impact on calculated discharge and charge potentials and suggests that long-range dispersion interactions should always be considered when graphene-based materials are modelled as electrocatalysts. Finally, we offer general guidelines for designing new ORR catalysts for M-O2 cells in terms of the optimization of the interactions of catalyst surface with reaction intermediates.

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