Evaluation of ionic mobility and transference number in a polymeric solid electrolyte by isothermal transient ionic current method

We proposed a new method for evaluating mobilities of both Li+ and SCN− ions in a polymeric solid electrolyte formed by poly (ethylene succinate) and LiSCN. The method is based on the isothermal transient ionic current (ITIC) technique by using an ion-blocking platinum electrode and an ion-reversible lithium electrode. The differences of the ITIC profiles, depending on the kind of the electrodes, provided both mobilities of Li+ and SCN− ions, and their assignment. The mobilities of Li+ and SCN− ions at 90 °C were 1.3–4.2×10−6 cm2 V−1 s−1 and 5.3–10.7×10−8 cm2 V−1 s−1, respectively. The transference number of Li+ ions was 0.92–0.99.