To explore the relevance of battery inconsistency parameters and evaluate the cells inconsistency in Lithium-ion battery module. A comprehensive evaluation method of cells inconsistency in Lithium-ion battery module is proposed. Experimental tests for 8 series battery cells have been carried out to obtain the inconsistency data including internal resistance, voltage, capacity. An inconsistency evaluation model taking internal resistance, voltage and capacity as the inputs is established by using the information entropy-grey relational analysis (GRA). The inconsistency of 8 series lithium-ion cells is comprehensively evaluated by the proposed model under the conditions of accelerated aging experiment at 25 °C and 3C rate. The results show that the proposed method can evaluate the cells inconsistency and identify cells inconsistency feature distribution.
Keywords Lithium-ion battery, battery inconsistency evaluation, grey relational analysis (GRA), information entropy