Automated electrochemical manufacturing system for biochar / polyaniline composite anodes

Abstract

An automated system for the production of composite electrodes, consisting of an ultrasonic suspension preparation unit, a precision drop casting mechanism and a controlled electrochemical three-electrode reactor cell.

Description

Application area of ​​the invention

[0001] The present invention relates to a precision manufacturing system for the production of high-performance biochar / polyaniline composite anode electrodes for microbial fuel cells (MFCs) and bioelectrochemical reactors. Background of the invention

[0002] Microbial fuel cells (MFCs) offer a sustainable approach to wastewater treatment combined with energy generation. However, their efficiency is often limited by the performance of the anode electrode. Conventional carbon electrodes exhibit low electrical conductivity and an insufficient surface area for effective microbial colonization. While biochar, particularly from sustainable sources such as peanut shells, represents an environmentally friendly material (100), its inherently low conductivity remains a significant obstacle. The necessary coating of the biochar with conductive polymers such as polyaniline (PANI) requires precise control to achieve uniform deposition and optimal morphology. Current manual fabrication methods do not offer the repeatability and scalability required for commercial application.There is an urgent need for a standardized, automated manufacturing system capable of reliably producing highly conductive composite anodes with a large surface area. This ensures consistent power output and accelerates the market launch of MFC technology. Summary of the invention

[0003] The present invention relates to a novel controlled electrochemical fabrication system (CEFS) that automates and standardizes the production of biochar / polyaniline (PANI) composite anodes. The CEFS comprises an ultrasonic suspension preparation unit, a precision drop-casting mechanism, and a three-electrode reactor cell (ERC) controlled by a dedicated power and potential control unit (PPCU). This integrated system was developed to overcome the technical challenges of uniform biochar deposition (102) and controlled PANI electropolymerization (103), thereby ensuring an electrode with improved conductivity and optimized surface properties for efficient microbial adhesion.

[0004] The primary technological advantage of the CEFS lies in the precise control of the electropolymerization process within the ERC. The PPCU employs a specific, reproducible electrochemical sequence that actively promotes the formation of a highly porous PANI structure, particularly nanofibers and nanoparticles (104), on the biochar base. This controlled morphology maximizes the electrochemically active surface area and enables superior charge transfer kinetics, thereby significantly enhancing the potential for bioelectricity generation when the final anode electrode is integrated into an MFC (105). Detailed description

[0005] The invention describes the Controlled Electrochemical Fabrication System (CEFS), a device for the automated and standardized production of high-performance biochar / polyaniline composite anode electrodes.

[0006] The system begins with the biochar suspension preparation unit (BSPU). The BSPU is equipped with an ultrasonic probe and a high-speed magnetic stirrer to ensure a homogeneous distribution of the peanut shell biochar powder (100) and the conductive additives in the binder and solvent (101). This homogeneous suspension is crucial for the consistency of the finished electrode layer.

[0007] After the suspension is prepared, the material is transferred to the precision drop casting (PDCM) system. The PDCM consists of a computer-controlled XYZ gantry system with a calibrated microsyringe or dispenser. This system automatically dispenses an exact, predefined volume of the biochar suspension (10 2 ) onto the substrate material (e.g. carbon fabric or graphite) and thus ensures a uniform and reproducible layer thickness and density.

[0008] The substrate is transferred to the electrochemical reactor cell (ERC) for the crucial polymerization step. The ERC is a sealed, temperature-controlled vessel designed to accommodate the substrate as the working electrode in a three-electrode configuration (working electrode, platinum counter electrode, and silver / silver chloride reference electrode).

[0009] The PANI deposition process (103) is controlled by the power and potential control unit (PPCU). The PPCU is a dedicated, programmable power source that precisely electrochemically controls the aniline monomer solution within the ERC, typically by means of cyclic voltammetry or chronoamperometry.

[0010] The PPCU software is programmed with specific parameters optimized for the formation of the desired highly conductive PANI structure. This controlled polymerization process avoids the formation of insulating PANI films and instead promotes the formation of highly porous nanofibers and nanoparticles (104) that maximize the three-phase interface.

[0011] The resulting $\text{nanostructured}$ morphology significantly increases the specific surface area of ​​the electrode, thus providing maximum available sites for both electrochemical charge transfer and microbial colonization, which forms the basis for improved power generation in the final MFC application.

[0012] After electropolymerization, the electrode is transferred to a controlled drying and curing module (CDCM). The CDCM ensures regulated temperature and humidity to stabilize the PANI composite structure and thus guarantee the chemical integrity and physical durability of the finished anode electrode.

[0013] The CEFS device ensures high throughput and unprecedented uniformity compared to manual methods. This standardization enables the scalable and cost-effective production of high-performance composite anodes, thus facilitating the wider commercial application of microbial fuel cells (MFCs) (105) for bioenergy production from wastewater.

[0014] In summary, the CEFS offers a fully integrated, automated platform for the production of a superior biochar / polyaniline anode, thus representing a next-generation solution for bioelectrochemical applications.

Claims

[1] An automated system for the production of composite electrodes, consisting of an ultrasonic suspension preparation unit, a precision drop casting mechanism and a controlled electrochemical three-electrode reactor cell. [2] The system according to claim 1 further comprises a power and potential control unit configured to precisely apply a specific electrochemical sequence to the reactor cell to enable the electropolymerization of aniline on a biochar-coated substrate. [3] System according to claim 2, wherein the precision drip casting mechanism is an automated portal system calibrated to apply a uniform volume of biochar suspension to the substrate, ensuring a constant electrode thickness and ohmic resistance. [4] System according to claim 2, wherein the electrochemical sequence is optimized to promote the formation of polyaniline in a nanofiber and nanoparticle morphology to maximize the specific surface area of ​​the electrode and electrogenic microbial adhesion.