论文标题

Marcus-Hush-Chidsey动力学在电极 - 电解质界面上

Marcus-Hush-Chidsey Kinetics at Electrode-Electrolyte Interfaces

论文作者

Kurchin, Rachel, Viswanathan, Venkatasubramanian

论文摘要

电极 - 电解质界面的电化学动力学限制了包括燃料电池和电池在内的设备的性能。尽管已经确认了超越巴特勒 - 沃尔默动力学并结合电极状态电子密度的影响的重要性,但仍然缺乏将这些方面直接纳入电化学性能模型的统一框架。在这项工作中,我们在计算各种电极 - 电解质界面的电化学反应速率时明确说明状态的DFT计算的密度。我们首先显示了与Li金属电沉积有关的两种情况,并在LI表面和Cu表面(无阳极构型)上剥离。对于LI等状态平坦的病例,反应速率的偏差很小,但由于非分散性D波段而产生较大变化,对于CU而言是显着的。最后,我们考虑了一个由LIF和LI $ _2 $ CO $ _3 $组成的固体电解质相(SEI)(SEI)的半导体情况,并注意Fermi级别在接口处的重要性,这是由于那里发生的氧化还原反应所钉住的。我们将反应速率的不对称性视为这种方法中自然的排放/电荷的函数。这项工作中使用的分析代码可在GitHub上开放源。

Electrochemical kinetics at electrode-electrolyte interfaces limit performance of devices including fuel cells and batteries. While the importance of moving beyond Butler-Volmer kinetics and incorporating the effect of electronic density of states of the electrode have been recognized, a unified framework that incorporates these aspects directly into electrochemical performance models is still lacking. In this work, we explicitly account for the DFT-calculated density of states numerically in calculating electrochemical reaction rates for a variety of electrode-electrolyte interfaces. We first show the utility of this for two cases related to Li metal electrodeposition and stripping on a Li surface and a Cu surface (anode-free configuration). The deviation in reaction rates is minor for cases with flat densities of states such as Li, but is significant for Cu due to nondispersive d-bands creating large variation. Finally, we consider a semiconducting case of a solid-electrolyte interphase (SEI) consisting of LiF and Li$_2$CO$_3$ and note the importance of the Fermi level at the interface, pinned by the redox reaction occuring there. We identify the asymmetry in reaction rates as a function of discharge/charge naturally within this approach. The analysis code used in this work is available open-source on Github.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源