Insight into sodium penetration with mechanical behaviors of carbon electrodes by large-scale reactive molecular dynamics simulations

Sodium penetration of carbon electrodes leads to large deformation and concurrent changes in their mechanical properties. Taking the industrial carbon cathode for aluminum smelting as an example, this work constructed a complex molecular model of the carbon cathode (over 5,0000 atoms). Then, the large-scale ReaxFF simulations were applied to correlate the microstructural changes with the associated macroscopic response, revealing the atomic-scale mechanisms of sodium penetration and its relation to mechanical behaviors including sodium expansion and creep deformation. In particular, we provided a detailed knowledge involving the microstructural origin of mechanical deterioration and the molecular basis of cathode strength. This study might be beneficial to improve the understanding of the structure-property relationship, and provide theoretical support for the optimal design of carbon electrode materials against failure.