Comparative analysis of electrochemical properties and thermal behaviors of sodium ion and lithium ion batteries

Sodium-ion batteries (SIBs), characterized by their abundant raw material sources and cost-effective manufacturing processes, have emerged as one of the most promising battery technologies. However, the existing literature on the electrochemical and thermal generation characteristics of SIBs remains limited. This dissertation conducts a comparative investigation of the electrical-thermal properties of 18650-type SIBs and Lithium-ion batteries (LIBs) from both macroscopic and microscopic perspectives. The initial phase of the study involved conducting experiments under standard operating conditions, with variations in ambient temperatures and discharge rates. Furthermore, investigations into overcharging and thermal runaway (TR) were conducted under extreme conditions, with concurrent studies on heat generation and electrochemical analyses. The underlying mechanisms responsible for macroscopic performance variations were elucidated through microstructural characterization. The experimental findings reveal that at an ambient temperature of 0°C, the State of Charge (SOC) of Sodium-Ion Batteries (SIBs) exceeds that of Lithium-Ion Batteries (LIBs) by 13.93%. Under standard operating conditions, LIBs demonstrate enhanced cyclic capacity retention relative to SIBs, albeit with higher thermal generation. Under abusive conditions, the performance of SIBs markedly deteriorates, accompanied by a substantial increase in heat generation, surpassing that of LIBs. Following abuse, SIBs experience thermal runaway, attaining a peak temperature of 273.9°C. The performance degradation is primarily attributed to severe sodium deposition on the anode and the subsequent detachment of active materials. These findings furnish essential experimental data and theoretical underpinnings for the industrial deployment of SIBs, while providing critical insights for optimizing their production processes and improving thermal safety performance.