Enhanced electrochemical performance of polyaniline-based electrode for supercapacitors in mixed aqueous electrolyte

• DOI: 10.1016/j.electacta.2020.136348
• Publication Date: 2020-04-29T12:30:05Z
• Authors: Qi Wang; Jinmei Li; Dongshan Wang; Jingye Niu; Pengcheng Du; Juanli Liu; Peng Liu
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy; 3. Good health

Abstract Aqueous electrolytes can provide high capacitance owing to their high ionic conductivity. In the present work, the aqueous electrolyte was optimized for the polyaniline (PANI)-based electrode, with a flexible PANI coated polylactic acid/multi-walled carbon nanotubes (PLA/MWCNTs) composite film as a model electrode. The electrochemical performance of the PLA/MWCNTs composite film electrode was investigated in the most used acidic and neutral electrolytes, H2SO4 and Na2SO4. As a result, the optimized aqueous electrolyte for the PANI-based electrodes in supercapacitor was achieved as 1.1 mol L−1 H2SO4/0.1 mol L−1 Na2SO4 mixed electrolyte (1.1–0.1), in which the specific capacitance was enhanced by 17.28% in comparison with the commonly used acidic electrolyte (1.0 mol L−1 H2SO4). The analysis of the electrode and electrolytes after electrochemical cycles demonstrated that the addition of the neutral electrolyte Na2SO4 could efficiently inhibit the acid-induced hydrolysis of PANI, improving the specific capacitance and cycling stability. The finding is expected to promote the development of the advanced aqueous polyaniline-based supercapacitors.