Effect of anode structural designs on diffusion stress distribution in sodium-ion batteries

A temperature–pressure–electrochemical coupling model is developed using finite element simulations to analyze the distribution of diffusion stress in anode particles with different structures and sizes under low-temperature conditions, with NaVPO₄F–HC sodium-ion batteries used as a case study. Our calculations show that optimizing the structural design and size of anode particles can considerably lower von Mises stress at low temperatures. Of the three structures analyzed in this study, the yolk structure proved to be the most effective. This structure provides sufficient space for electrode particle expansion, thereby effectively reducing diffusion stress. Additionally, analysis of von Mises stress distribution in the yolk–shell structure across various low temperatures, revealed that the properties of the yolk structure remained largely stable at low temperatures. This research provides an effective method for determining optimal anode particle structures and sizes in sodium-ion batteries at low temperatures, supporting the development of sodium batteries with improved mechanical properties.