Multi-plate, thin-film manganese oxide electrodes were synthesized via the thermal decomposition of a complex of manganese (II) formate (MnF) and triethylenetetramine (TETA) at 260 degrees C. These approximately 200 nm thick plates contained 50-100 nm nanoparticles and were obtained from a complex of TETA and MnF with a molar ratio of 4. A cyclic voltammetry (CV) test confirmed the pseudocapacitive properties of these multi-plate, thin-film manganese oxide electrodes. The specific capacitance of multi-plate, thin-film electrodes with a mass loading of 10 mu g was calculated from a CV curve at 10 mV/s that reached 938 F/g. The specific capacitance degradation was measured via a galvanostatic charge-discharge of 0.5 mA/cm(2) and was almost stable after 1,000 cycles, which resulted in good cycle stability. Thus, an electrode of non-composite manganese oxide with high specific capacitance and good stability was obtained via a simple one-step fabrication process by thermal decomposition. (C) 2016 Elsevier Ltd. All rights reserved.