In this study, flower-like Bi2O2CO3 microsphere and Bi2O2CO3/RGO-(X) [X=50, 75, and 100 mg of RGO] pseudocapacitor electrode materials have been successfully synthesized by a facile hydrothermal method. The pseudocapacitor electrodes were characterized by FE-SEM, HR-TEM, XRD, FT-IR, and TGA measurements. Electrochemical performance for pseudo capacitive properties of pure Bi2O2CO3 and Bi2O2CO3/RGO-(X) composites has been further tested by cyclic voltammetry, galvanostatic charge discharge, and electrochemical impedance spectroscopy. The results show that the Bi2O2CO3 and Bi2O2CO3/RGO-(X) electrodes exhibited the specific capacitance value of 96, 260, 478, and 860 Fg(-1), respectively, at a scan rate of 5 my s(-1). Moreover, the cyclic performance for Bi2O2CO3/RGO-100 composite (96% capacity retention at 20 mV s(-1)) is superior to that of pure Bi2O2CO3 (58% capacity retention at 20 mV s(-1)). Besides, the Bi(2)O(2)CO(3)3/RGO-100 exhibited a high specific capacitance of 375 F g(-1) at 0.2 A/g with enhanced rate capability (342.2 Fg(-1) at 5 A/g) and cyclic stability (84.5% retention after 1000 cycles at 5 A/g). Such a fabrication of hybrid nanocomposite electrode (Bi2O2CO3/RGO-100) may bring the development of excellent pseudocapacitor with superior electrochemical performance. (C) 2017 Elsevier Ltd. All rights reserved.