Temperature dependency of diagnostic methods in lithium-ion batteries

Accurate estimation of battery performance and capacity is essential for assessing the capabilities different batteries determining state health (SOH). Typically, diagnostic methods such as constant current charge/discharge, interrupt, electrochemical impedance spectroscopy (EIS) are demonstrated in laboratory tests with controlled environmental conditions. In real-world applications, electric vehicles, subjected to wide temperature ranges control SOH often not possible. This study investigates how techniques influenced by small variations order determine suitable windows over which can be performed without negatively influencing results. A lithium-ion 18650 cell charge, pulse discharge EIS between 0 °C 40 2 increments. The influence operating on abilities incremental analysis (ICA), differential voltage (DVA) equivalent circuit fitting explored. findings this indicate that lead significant errors ability diagnose degradation mechanisms, particularly at low temperatures (<10 °C). If ±4 or greater expected characterisation tests, then regulation will required ensure accurate diagnostics. based diagnostics was shown less sensitive than voltage-based ICA. • Influence variation accuracy explored Small (±2 °C) significantly affect accuracy. Impedance require narrow window (±1 Temperature should considered when evaluating new techniques.