How does a low-temperature environment affect the discharge capacity and internal resistance of lithium-ion batteries

Abstract

The study investigated the performance degradation of 18650 lithium-ion batteries under low-temperature environment. A Arduino-based testing system was used to conduct comparative discharge experiments at 25℃ and approximately -10℃. The system detected and collected the real-time current, voltage and temperature data, and the discharge capacity was calculated by current integration. The results of this study reveal that low-temperature environment will greatly increase internal resistance, lower the discharge plateau and reduce capacity of a lithium-ion battery. The root cause lies in higher electrolyte viscosity and slow lithium-ion migration. The article summarizes existing optimization methods, analyzes experimental limitations, and provides practical improvement strategies for batteries used in electric vehicles and portable electronics.