Synergistic Charge Redistribution and Structural Evolution in Three-Dimensionally Printed Mn-Prussian Blue...

Area of Science:

• Materials Science
• Electrochemistry
• Additive Manufacturing

Background:

• Three-dimensional (3D) printing enables fabrication of complex, multifunctional electrodes.
• Integrating diverse materials like polylactic acid (PLA), carbon black (CB), reduced graphene oxide (rGO), and manganese hexacyanoferrate (MnHCF) is key for advanced energy storage.

Purpose of the Study:

• To develop and characterize 3D-printed PLA/CB/rGO/MnHCF electrodes.
• To understand the cooperative electrochemical mechanisms governing their performance and long-term stability.

Main Methods:

• Fabrication of 3D-printed electrodes using PLA, CB, rGO, and MnHCF.
• Structural analysis via Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX).
• Electrochemical evaluation using galvanostatic cycling, cyclic voltammetry, and post-cycling characterization (Raman, FTIR).

Main Results:

• Homogeneous dispersion of MnHCF and carbonaceous additives within the PLA matrix was confirmed.
• PLA/CB/rGO electrodes showed capacitive behavior; MnHCF addition introduced redox activity (Fe/Mn transitions).
• Galvanostatic cycling revealed enhanced capacitance, high reversibility, and a significant capacitance increase over 3,500 cycles, attributed to surface area expansion and site activation.

Conclusions:

• A cooperative mechanism was identified where the insulating PLA matrix facilitates charge redistribution, enhancing redox activity.
• The insulating nature of PLA acts as a driver for progressive activation and improved conductivity.
• 3D-printed PLA/CB/rGO/MnHCF electrodes exhibit stability and promise for scalable, tunable energy storage applications.