Particle size dependence of the electrochemical properties of SrMnO 3 supercapacitor electrodes

In this letter, we report on the simple process of preparing perovskite oxide SrMnO 3 and the studying of the size effect on electrochemical properties for high-performance supercapacitor electrode. The high-crystalline micro-sized and nano-sized perovskite oxide SrMnO 3 particles were successfully synthesized by a simple solid-state reaction, followed by a simple size reduction using high-energy ball milling. The electrochemical properties of the SrMnO 3 had intriguing results on both sizes of particle, especially when comparing between before and after cycles. After a size reduction, the specific capacitance of the particles increased approximately twofold. Interestingly, the micro-sized SrMnO 3 gained ∼500% its initial specific capacitance after 3000 successive cycles due to electrochemical nano-feature activation and oxygen-vacancy production, while the specific capacitance for the nano-sized SrMnO 3 remained almost unchanged. Our work suggested a cost-effective and simple technique for high-performance perovskite-based supercapacitor electrodes by achieving the desired performance.