Scrutinizing the charge storage mechanism in SrO based composites for asymmetric supercapacitors by diffusion-controlled process

Optimization of suitable electrode material flashing high electrochemical performance is the main hindrance in energy storage applications. Metal oxide-based electrode materials are promising candidate which greatly promotes the sustainable development. Herein, strontium oxide (SrO) is synthesized from sonochemical method followed by calcination. Incorporating polyaniline (PANI) and graphene (Gr) intensify the materials performance. Three asymmetric devices are designed using SrO, its composites (SrO/PANI and SrO/PANI/Gr) and activated carbon (AC) as an electrode and electrolyte-soaked separators are sandwiched in solidly packed cell assembly. Electrochemical measurements are performed to scrutinize the inherent properties. After that, Dunn's model is applied to evaluate the capacitive and diffusion-controlled contributions. The obtained result divulges that SrO/PANI/Gr//AC exhibits more diffusive-controlled contribution and reveals a battery type behavior due to the contribution of PANI in redox reactions. Thus, this work delivers a route to synthesize metal oxides-based composites and a systematic approach to analyze the charge storage mechanism in asymmetric supercapacitors.