Ac impedance analysis of lithium ion battery under temperature control

► Ac impedance of LIB was measured at low temperature to enlarge the impedance. ► At the temperature below 0 °C another arc of semicircle appeared. ► At 20 °C the hidden arc was found to be small. ► The hidden arc was also overlapping with kinetic impedance and inductive locus. ► The hidden impedance response was attributed to the SEI impedance.