Nickel ferrite doped polyaniline composites: Synthesis and analysis for a high‐performance symmetric pseudo‐supercapacitor

This work is conducted to improve the electrochemical performance of PANI with the incorporation of spinel‐type transition metal oxide, that is, 1 wt.% of nickel ferrite (NiFe2O4) (NF). The addition of NiFe2O4 into the PANI matrix is accomplished via in situ oxidative polymerization approach at a very low temperature (0‐5°C). It is observed that the various valence states of NiFe2O4 in the electrolytic ions considerably increase due to formation of a well‐interconnected conducting network with PANI. The requisite interaction of PANI/NiFe2O4 is verified by Raman analysis and Fourier Transform Infrared Spectroscopy (FTIR). PANI1:1/NF1 ratio of the composite facilitates strong conducting route improving delocalization of the electrons in the polymeric chain resulting in extra stability of the system. It is observed that NF nanoparticles fills the gaps in the polymeric matrix rendering to attain highest specific capacitance of 758 F g−1 of the PANI 1:1/NF1 electrode cell as compared to bare PANI1:1 (677 F g−1), PANI1:2 (500 F g−1), NF (253 F g−1) and other PANI1:2/NF2 (686 F g−1) samples at 10mV/s. The PANI1:1 device also shows energy density ~ 54 W kg−1 at 0.3 mA/cm2 with corresponding power density at ~1705 W kg−1, and the cyclic stability ~97% after 10,000 GCD cycles. The said device also exhibits a lower charge transfer resistance (Rct) 0.35 Ω as compared to other fabricated devices. NiFe2O4 acts as a ‘superhighway’ for charge transportation between PANI, which is beneficial for supercapacitors.