A study on time-dependent low temperature power performance of a lithium-ion battery

Time-dependent elementary polarizations of a lithium-ion battery are quantitatively investigated below room temperature in an attempt to determine the critical factors affecting low temperature power decline. From three-electrode impedance measurements and the theoretical analysis of the phenomenological equivalent circuit, the proportional contribution of the internal resistances to the total polarization is satisfactorily analyzed as a function of the pulse discharging time. The results prove that the interfacial charge-transfer resistances of the anode (graphite) and the cathode (lithium cobalt dioxide) make the highest contributions to the low temperature power decline. On this basis, a strategy for the material design to enhance the low temperature performance is suggested with two examples of surface modification and hybridization with an electrochemical capacitor.

► A viable way to diagnose the low temperature power decline of a lithium-ion battery during the pulse discharging process was suggested. ► The proportional contribution of the internal resistances to the total polarization was systematically analyzed as a function of the pulse discharging time. ► A strategy for the material design to enhance the low temperature performance is suggested with two examples of surface modification and hybridization with an electrochemical capacitor.