Titanium oxide nanoparticle-embedded mesoporous manganese oxide microparticles for supercapacitor electrodes

Due to increased contact between electrode and electrolyte, using nanoparticles (NPs) of manganese oxide (MnO2) as an electrode material improves the specific capacitance (Csp) of supercapacitors. However, this material is not yet commercially feasible because the voltammetric response drops rapidly with electrode thickness due to its poor electrical conductivity; also, the large-scale production of MnO2 NPs is significantly difficult. To overcome these limitations simultaneously, we propose mesoporous MnO2 microparticles incorporated with titanium dioxide (TiO2) NPs as the electrode material. The synthesized microparticles can be easily isolated with a simple filtration process, while the specific surface area is comparable to that of MnO2 NPs. The incorporation of TiO2 NPs improves the specific capacitance as well as the voltammetric response. A maximum Csp of 479 F/g measured at 10 mV/s is obtained and the retention at 100 mV/s is 61.3%, which values are 4.7 and 1.5 times larger, respectively, than those values of the TiO2-free MnO2 electrode. •Electrode of TiO2 nanoparticle-embedded mesoporous MnO2 microparticles was fabricated.•It leads to improved contact with electrolyte and easier filtration, simultaneously.•Maximum Csp of 479 F/g at 10 mV/s and retention of 61.3% were obtained.•Effect of porous structure and TiO2 incorporation was analysed theoretically.