Pulsed Charging Strategies for Lithium Dendrite Suppression:Phase-Field Insights into Duty Cycle and Stack Pressure Effects

Abstract In lithium batteries, the non-uniform deposition of lithium metal initiates the nucleation and growth of lithium dendrites. Severe dendritic propagation not only causes rapid capacity decay but also triggers internal short circuits, leading to critical safety hazards. Therefore, investigation of lithium dendrite growth mechanisms is crucial for lithium batteries. Lithium dendrites primarily form during the charging process. This study establishes a phase-field-based numerical model to investigate the influence of charging protocols on lithium dendrite growth during battery charging. Furthermore, a mechano-electrochemical coupling phase-field model is developed to analyze dendrite evolution in solid-state electrolytes (SSE). The results demonstrate that pulsed voltage charging protocols effectively suppress dendrite formation in both liquid and SSE. The duty cycle is defined as the ratio of the charging duration to the total cycle period in lithium battery operation. In liquid electrolytes, dendrite growth exhibits significant dependence on duty cycle: higher duty cycles accelerate dendrite propagation and promote sharper morphological features. This study investigates the synergistic effects of stack pressure and pulsed charging in SSE. It was found that the duty cycle exhibited negligible influence on lithium dendrite growth, whereas stack pressure was identified as the dominant factor governing dendritic propagation.