In this study, a composite dispersion of conductive additives, comprising carbon nanotubes (CNT) and Denka Black (DB), was prepared via a high-pressure homogenization (HPH) process. This approach was designed to overcome the limitations of carbon black-based conductive networks in lithium-ion battery cathodes. Raman mapping confirmed the uniform dispersion of the CNT+DB mixture, while scanning electron microscopy revealed that the composite additive formed a more continuous point-to-line conductive network compared to individual CNT or DB electrodes. Electrical conductivity measurements and electrochemical impedance spectroscopy revealed higher electronic conductivity and lower charge-transfer resistance of the CNT+DB than the individual additives. During cyclic voltammetry, the CNT+DB electrode exhibited the highest peak current among the samples, suggesting more active redox behavior. Electrochemical performance tests demonstrated that the CNT+DB electrode retained 55.7% of its initial capacity at 5C and maintained 71.9% of its capacity during long-term cycling at 2C, exhibiting enhanced high-rate stability. These findings indicate that the three-dimensional conductive network created by combining CNT and DB effectively enhances electron pathways and stabilizes ion transport within the electrode.
A non-enzymatic glucose sensor was fabricated via a straightforward, single-step, coordination-driven in situ electrodeposition of a chitosan–Cu2+ hydrogel. This method utilizes electrochemically generated Cu2+ ions, which directly coordinate with the amine (–NH2) and hydroxyl (–OH) functional groups of chitosan chains to form a uniform, catalytically active matrix. Electrochemical analysis using the Lingane equation quantified the coordination environment, yielding a high stability constant (Ks = 7.04 × 104) and a fractional coordination number (j = 0.67). Atomic force microscopy (AFM) revealed that the hydrogel porosity varied with chitosan concentration, while Fourier-transform infrared spectroscopy (FT-IR) confirmed strong Cu2+ coordination with chitosan’s functional groups. The resulting hydrogel acts as a robust scaffold, effectively immobilizing the Cu2+/Cu3+ redox couple, which serves as the active center for glucose electrooxidation. An optimized sensor, integrated with single-walled carbon nanotubes (SWCNTs) to enhance charge transport, demonstrated excellent analytical performance, achieving a low detection limit of 11.9 μM and high selectivity. This work presents a simple, cost-effective, and stable electrochemical sensing platform with significant potential for non-enzymatic diagnostics.
