Reduced graphene oxide (rGO)-polyaniline (PANI) supercapacitors (SCs) are tested with 1 M LiCl, Li₂SO₄, and H₂SO₄ electrolytes. The SC performance is evaluated by electrical impedance spectroscopy, cyclic voltammetry (CV), and galvanostatic charging/discharging measurements. Electrochemical experiments indicate that rGO-PANI SCs with lithium salt electrolytes show a large pseudocapacitance (PC) effect whereas that with H₂SO₄ electrolyte shows a large electrical double-layer capacitance (EDLC) effect. The rGO-PANI SC with H₂SO₄ electrolyte has the largest areal capacitance of 48.83 mF/cm², whereas those with LiCl and Li₂SO₄ electrolytes have the areal capacitances of 31.69 mF/cm² and 22.35 mF/cm², respectively. After a 10,000-cycle CV stability test, the rGO-PANI SC with Li₂SO₄ electrolyte shows some ion embedding, resulting in better cycling stability than those of SCs with LiCl and H₂SO₄ electrolytes.