Research on Overcharge and Overdischarge Effect on Lithium-Ion Batteries

Commercial lithium-ion phosphate batteries were tested to investigate their responses to overcharge and overdischarge conditions. During overcharge tests, cells were charged at 1C successively until certain visual symptom such as gas release or vent burst occurred. While during overdischarge tests, cells were discharged and kept at 0V or even negative polarity. Parameters such as internal temperature, cell voltage and ac impedance were monitored and recorded for analysis of the abusive process. Tested cells presented failures in different levels. Along with the post-disassembly examination and electrochemical analysis, this paper connects the symptoms, effects and consequences of overcharge and overdischarge phenomena and tries to establish the early precaution approach for battery failures to guarantee the safety of battery applications.