Fig. 2: The electrochemical performance of C-PANI.

a CV curves of Fe||PANI and Fe||C-PANI at 2 mV s−1. b The discharging–charging profiles of PANI and C-PANI at a specific current of 5 A g−1. c The discharging–charging profiles of C-PANI at specific currents ranging from 5 A g−1 to 25 A g−1. d The rate performance of C-PANI and corresponding Coulombic efficiency. e Specific capacity and specific current comparisons of Fe||C-PANI to previously reported aqueous Fe-ion batteries. f The long-cycle profiles for C-PANI and conventional PANI at 25 A g−1. g Comparisons of cycle numbers and capacity retention of Fe||C-PANI with previously reported aqueous Fe-ion batteries. The test temperature is 28 °C ± 1 °C.