High-Performance and Ultrafast Symmetric Supercapacitors Based on Cu(II)-Doped SrSnO<sub>3</sub> Perovskites
Adervando Silva, Mohamad Hasan Aleinawi, Emre Erdem, Brendan J. Kennedy, Aurelian Catalin Galca, I. M. G. Santos, Arpad Mihai Rostas, André Luiz Menezes de Oliveira
Abstract
High Resolution Image Download MS PowerPoint Slide Herein, Cu(II)-doped SrSnO 3 perovskites (SrSn 1– x Cu x O 3, namely SSO:Cu x ) were prepared by a modified Pechini method and applied as supercapacitors (SCs) for the first time. The effect of dopant concentration ( x = 1, 2.5, and 5 mol %) was investigated to fine-tune the structural and electronic properties to design potential candidates as SCs. The SSO:Cux samples were characterized by conventional XRD and synchrotron XRD (S-XRD) combined with Rietveld refinements and spectroscopic analyses, such as Raman, FTIR, UV–vis, EPR, and XANES/NEXAFS. The electrochemical performance of the SSO:Cux samples was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic cycling with potential limitation (GCPL). It was evidenced that incorporating 2.5 mol % Cu(II) into the SrSnO 3 perovskite lattice (SrSn 0.975 Cu 0.025 O 3, SSO:Cu2.5) led to a significant change in structural disorder and electronic properties, which play an essential role in creating a mixture of point defects such as reduced Sn 3+ and Cu + cations, and oxygen vacancies (V O ). The SC device constructed with the SSO:Cu2.5 material showed a specific capacitance of 613 F g –1 at a scan rate of 1 mV s –1, with a remarkable specific energy density and specific energy power of 25.42 W h kg –1 and 32678.57 W kg –1, respectively, which are higher than those observed for any other available perovskite-based SCs. This performance was primarily attributed to the formation of mixed Sn 4+ /Sn 3+ and Cu 2+ /Cu + cations, which alter the structural and electronic properties of SrSnO 3 . Our findings indicate that an improved capability to store high energy and power may be achieved by fine-tuning the Cu(II) dopant concentration in the lattice and controlling the formation of undesired phases. This offers experimental guidance to design other Cu-doped perovskites as alternative materials for energy storage applications.