1：Experimental Design and Method Selection:

Manganese oxide nanofoam was prepared by pulsed laser deposition from a metallic Mn target in a 5 Torr pressure O2 buffer atmosphere. The as-prepared samples were heat-treated at different temperatures (300?C-500?C) in air.

2：Sample Selection and Data Sources:

Samples for morphology and cross-sectional studies were deposited on Si(100) wafers, and samples for electrochemical studies were prepared on stainless steel sheets.

3：List of Experimental Equipment and Materials:

A pulsed Nd:YAG laser (1064 nm wavelength, 7 ns pulse duration and 10 Hz repetition rate) was used for target ablation. Field-emission scanning electron microscopy (SEM-FEG, JEOL JSM7100F) and high-resolution transmission electron microscopy (HRTEM, JEOL JEM2100F) were used for morphology investigation. Raman spectroscopy (Witek Alpha-300R Raman Microscope, 532 nm wavelength excitation) and powder XRD (Bruker D8 diffractometer) were used for structure analysis. X-ray Photoelectron Spectroscopy (XPS) was used for electronic structure details.

4：Experimental Procedures and Operational Workflow:

The samples were heat-treated in air for 90 minutes at 300?C, 400?C, and 500?C. The supercapacitive properties were tested by Cyclic Voltammetry (CV) in a

5：1 M Na2SO4 aqueous solution. Data Analysis Methods:

The specific capacitances (Cs) of the electrode were calculated from the CV curves according to the equation: Cs = Q/m?V.