A high over-potential binder-free electrode constructed of Prussian blue and MnO2 for high performance aqueous supercapacitors
coordination superamolecular networks, Prussian blue, high operating voltage, binder-free electrode, aqueous supercapacitors
Extending the potential window of aqueous supercapacitors (SCs) up to 2.0 V is still a great challenge. Based on their good dynamic structural reversibility and open framework structure, the coordination superamolecular networks (CSNs) exhibit rapid charge/discharge ability and excellent cycle stability. As a typical coordination superamolecular network (CSN), Prussian blue (denoted as CSN-PB), which self-assembled by the CN− ligand and iron ions is firstly in-situ grown on carbon cloth, followed by electro-deposition of MnO2 to form CSN-PB/MnO2 composite electrode. Benefiting from synergistic effect of the constituent components, as well as the open framework structure of CSN-PB, this composite electrode reaches a high potential window of 1.4 V (vs. Ag/AgCl) and delivers a good specific capacitance of 315.3 F·g−1 in aqueous electrolyte. An aqueous asymmetric device, constructed with CSN-PB/MnO2 composite as cathode and activated carbon as anode, can work in a stable potential window of 2.4 V, exhibits a high energy density of 46.13 Wh·kg−1 and excellent cycling stability with 85.5% capacitance retention after 20,000 cycles. This work provides a new concept of high dynamic structural reversibility from CSNs to increase the cell voltage of asymmetric SCs for further boosting energy density.
Tsinghua University Press
Gaowei Zhang,Hua Yao,Feng Zhang,Zitao Gao,Qiujun Li,Yangyi Yang,Xihong Lu, A high over-potential binder-free electrode constructed of Prussian blue and MnO2 for high performance aqueous supercapacitors. NanoRes.2019, 12(5): 1061–1069