Experimental study on influence of temperature and C-rate of discharge on performance of in-house fabricated 30Ah Li-ion prismatic cell made with LFP and MCMB
Abstract Experimental study was carried out to quantify the influence of temperature and different C-rate of discharge on in-house fabricated Lithium-ion (Li-ion) cell. 30Ah Li-ion cell is made of Lithium Iron Phosphate (LFP) cathode and Meso Carbon Micro Beads (MCMB) anode in prismatic configuration. Capability of Li-ion cell is defined by discharge capacity, voltage & power at different C-rate of discharge. Influence of 4 different current rates (C/5, C/2, 1C & 2C) at 5 different temperatures (−20, 0, 20, 40 and 60 °C) were studied. High discharge rate increases current density of cell which affect mass transport at electrode surface and electrolyte. Increased ohmic and concentration polarization at high rate of discharge decrease the original capacity. Average discharge voltage of cell is reduced gradually as operating temperature drop to below 20 °C. Electrochemical Impedance (EI) were measured on Li-ion cell in different frequency domain at different temperatures (−20, 0, 20 and 60 °C). The obtained impedance spectra were examined with an equivalent circuit using Zman software. The ohmic and charge transfer resistance displayed a solid dependence with respect to temperature.