The experimentation conducted focused on two main areas: refining the hybridization process of the cathodic material developed during the previous year—Na0.44MnO (NMO)—with graphite materials, and synthesizing an anodic electrode material that could be paired with the cathodic material synthesized at RSE laboratories.

The hybridization process of the NMO species aims to synthesize an electrode material with both good ionic and electronic conductivity. Typically, electrode materials exhibit good ionic conductivity but poor electronic conductivity. To address this, they are usually mixed with carbon materials to provide electronic conductivity, which is essential for the intercalation and deintercalation processes that define electrode performance. The goal of hybridization is to create a material with high conductivity in both domains, achieving a binding between the electrode material and a carbon-based material. Unlike solid mixtures commonly used for electrode fabrication, the synthesized material can leverage both its surface and bulk properties as an electrochemical supercapacitor.

Initial tests were carried out using synthesis specifications determined in 2019 and involved various graphite materials: Activated Carbon (AC), Conductive Carbon (CC), Carbon Nanofibers (CNF), and carbon (C) derived from organic material like sucrose. Early tests revealed that the reducing nature of the carbon materials in the reaction environment reduced manganese to too low an oxidation state, preventing the synthesis of NMO. Therefore, experimentation was redirected to hybridization with a manganese precursor such as MnO, which starts with a high oxidation state of manganese. Tests were conducted using hydrothermal techniques, adjusting experimental parameters such as precursor type and amount, contact time, and working temperature, to achieve the highest possible yield of active material and ensure good electronic conductivity. The characterization of different materials was performed using X-ray diffraction (XRD), which allows for qualitative and semi-quantitative determination of crystalline species formed during synthesis. To measure electronic conductivity, a specialized measurement cell was designed and constructed.

For the anodic material to pair with the NMO species, a literature review was initially conducted to identify promising materials, which included iron oxides, titanium oxides, titanium phosphates and pyrophosphates, and molybdenum oxides.

The techniques used for synthesizing the anodic electrode material varied. Specifically, hydrothermal and solid-state synthesis methods were employed depending on the material being targeted.

The characterization of anodic materials, like the cathodic ones, began with XRD to determine the synthesized crystalline species and calculate the concentration of the different components. Only materials with a predominant amount of active phase were subjected to further characterization. These materials were then examined morphologically using scanning electron microscopy (SEM) and used to create electrodes for electrochemical characterization, including cyclic voltammetry and charge-discharge testing.