Electrochemical kinetics study of Li-ion in Cu6Sn5 electrode of lithium batteries by PITT and EIS

Abstract The kinetics of Li-ion intercalation/alloying into Cu 6 Sn 5 electrode was determined by potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectroscopy (EIS) method. Although the Li-ion diffusion coefficient ( D Li ) values are relatively high (from 10 −11 to 10 −10  cm 2 /s) in the most voltage range, two minima (below 10 −11  cm 2 /s) in the D Li vs. voltage curve were observed at ∼0.4 and 0.1 V, coinciding with the voltage plateau in the charge/discharge curves, indicating reversible structural phase transition or order/disorder transition in the compound. The D Li derived from PITT and EIS were confirmed well both in the magnitudes and in the variation within Li composition (voltage) range.