A green approach to energy storage properties of polyaniline

Abstract

The green energy storage of polyaniline, without major wastages excreted into the environment is effectively demonstrated by using the polyaniline as supercapacitor electrode and the by-product obtained during the synthesis of polyaniline as its electrolyte. This green approach to the energy storage properties of sulphuric acid doped polyaniline (H-PANI) exhibited a substantial improvement in its energy storage, compared to the conventional approach of using an ionically conducting liquid as electrolyte like 1 M H₂SO₄ (SA), separately. The amelioration of 40.44% was achieved when the by-product obtained as supernatant liquid (SL) was used as electrolyte compared to SA. The H-PANI provided a specific capacity (Q) of 146.4 C g⁻¹, a specific energy (E) of 24.40 W h kg⁻¹ and a specific power (P) of 1.200 kW kg⁻¹ at 1 A g⁻¹ in the presence of SA. The Q of 205.6 C g⁻¹, E of 34.26 W h kg⁻¹ (similar range of E of Pb-acid batteries), P of 1.200 kW kg⁻¹ were achieved in the presence of SL at 1 A g⁻¹ and a high rate capability of 29.18% retention of initial Q up to 25 A g⁻¹ was also achieved. This approach is useful to harvest high energy characters from PANI.