Electrochemical properties of poly(2-acrylamido-2-methylpropane sulfonic acid) polyelectrolyte containing zwitterionic silica sulfobetaine for supercapacitors

A polyelectrolyte was made by combining poly (2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and silica–sulfobetaine silane (SiSB) zwitterion (ZW) for use in supercapacitors. The polyelectrolyte blend with 10 wt% SiSB applied for symmetric cells indicated a specific capacitance of 321 F g⁻¹ at 10 mV s⁻¹ which is almost two times larger than that of pure PAMPS. The electrolytes consisting of SiSB also showed higher ionic conductivity than that of pristine PAMPS electrolyte due to ionic channels generated the zwitterions, thereby accelerating ion activity in the electrolyte. The PAMPS with 10 wt% SiSB exhibited an excellent cycling stability of ~100% capacity retention over 5000 cycles compared to PAMPS with 73% retention. These results indicated a synergy effect via the silica-based zwitterion and the PAMPS which could be a prospective candidate for supercapacitors applications.