Supercapacitor devices based on multiphase MgTiO3 perovskites doped with Mn2+ ions

Abstract

Recently, perovskites have become a hotspot for researchers attempting to exploit metal and oxygen vacancies in structures of the form MTiO 3 , facilitating the convenient electron/hole migration, thus displaying interesting properties. Magnesium Titanate (MgTiO 3 ) is a prominent part of the perovskite class, exhibiting remarkable electrical, thermal, and chemical properties. Undoped and Mn-doped MgTiO 3 samples were obtained using a solid-state reaction starting from previously synthesized MgO and TiO 2 powders, which were separately doped with different Mn ion concentrations. The resulting multiphase materials with a major MgTiO 3 phase were thoroughly morpho-structurally analyzed employing XRD, STEM, Raman, PL, XPS, and EPR spectroscopy. The electrochemical results indicate that they show superior performance when used as electrode materials for supercapacitor application due to the high defect concentration as shown in EPR and PL spectroscopy and the ferroelectric behavior observed in XPS and XRD. When used in symmetric and asymmetric supercapacitor devices, they show promising results, with specific capacity values reaching up to 109 F/g for the symmetric and 609 F/g for the asymmetric devices, while energy and power density values reached 84.7 Wh/kg and 90.8 kW/kg respectively, proving a great potential in the energy storage field. • Mn-doped Magnesium Titanate (MgTiO 3 ) were obtained using a solid-state reaction from MgO and TiO 2 . • The MgTiO 3 -based materials were analyzed by XRD, STEM, Raman, PL, XPS, and EPR. • Specific capacity values reaching ∼ 110 F/g and ∼ 610 F/g were obtained when used in symmetric and asymmetric supercapacitor devices. • Energy and power density values reached 84.7 Wh/kg and 90.8 kW/kg, respectively.

Topics & Concepts