A Review of Internal Resistance and Temperature Relationship, State of Health and Thermal Runaway for Lithium-Ion Battery Beyond Normal Operating Condition

One of the most popular energy sources in electrical circuitry is the lithium-ion battery (LIB) and it can be found in a variety of products from the smallest unit such as Airpod, smartwatch, smartphone to as big as farming drones, industrial robots, and electric vehicles. But the usage of lithium-ion batteries is limited to a range of temperatures. The normal operating temperature range for LIB is 40°C~65°C. Despite this, there are still cases where operating LIB at high temperature is unavoidable for example deep earth pipeline inspection in the oil & gas industry, sterilization of medical tools in the medical industry, harsh condition robots and drones in the industrial sector, and high ambient power storage for photovoltaic system. Operating LIB beyond normal conditions will affect the battery in several ways. In this paper, the effect of temperature on internal resistance is demonstrated by several studies, the results show LIB internal resistance decrease as temperature increase. Operating LIB beyond normal operating conditions can also lead to faster battery degradation. Battery state of health (SOH) is used to indicate battery degradation level. A battery with a low SOH performs poorly in terms of power delivery compared to a high SOH battery. In addition, operating LIB beyond normal operating conditions, stresses such as thermal stress can damage the battery and instigate thermal runaway causing violent combustion and explosion.