An Internal Resistance Estimation Method of Lithium-ion Batteries with Constant Current Tests Considering Thermal Effect

摘要

This paper proposes a method for estimating internal resistance (R) of lithium-ion batteries considering R is a function of state of charge (SOC), current rate (I) and battery temperature (T_(bat)). Based on electrochemical mechanism of the batteries and general tests with a general testbed, the method designs a set of parameter estimation algorithm to estimate R. Compared with other methods such as Hybrid Power Pulse Characterization (HPPC) method with discrete R-SOC results and constant current test (CCT) method with no consideration of T_(bat) influence, this method can provide continuous R-SOC results with more R-SOC information and more accuracy by considering thermal effects. The algorithm details are discussed and test results verify the advantages.