Microbial fuel cell air cathode and preparation method thereof

Abstract

The invention discloses a microbial fuel cell air cathode which is composed of a diffusion layer thin film, a stainless steel net and an active layer thin film in an overlapped mode from an air side to an electrolyte side. The preparation method comprises the following steps of: mixing a carbon powder material which has good electrical conductivity and is hydrophilic and PTFE (Poly tetra fluoro ethylene) emulsion which is hydrophobic and is air conductive in ethanol; clustering through ultrasound and water bath; and finally rolling into a thin-film-shaped diffusion layer and an active layer; with the stainless steel net as an electrical conductive framework, overlapping and rolling so as to form the air cathode. The microbial fuel cell air cathode and the preparation method thereof have the following advantages: according to the preparation method, since electrical conductive carbon black is added into the air diffusion layer, the resistance of an air diffusion electrode is reduced; since the ultrasound stirring is carried out after the PTFE emulsion is dropped in, uniform and fine air holes can be formed in the electrode and the three-phase interface reduction site in the active layer is increased; and heating and curing are carried out twice in a muffle furnace, thus PTFE forms an air conveying pore canal of a three-dimensional network structure, the three-phase interface in the active layer is increased, and the microbial fuel cell air cathode is applicable to normalized mass production.

Description

technical field [0001] The invention relates to a method for manufacturing an air cathode of a microbial fuel cell, in particular to an air cathode of a microbial fuel cell and a preparation method thereof. Background technique [0002] Microbial fuel cell is a device that can convert biomass energy into electrical energy. It has the advantages of strong substrate adaptability, mild operating conditions, energy production without input energy, environmental friendliness, high reliability, and sustainable utilization. Especially when sewage is used as fuel, the effect of sewage treatment can also be achieved. Air diffusion electrodes using cheap and readily available oxygen as electron acceptors have been widely used in commercial fuel cells and metal-air batteries, such as alkaline metal-air batteries produced by ALUPOWER and Evionyx in the United States. Although air cathode is the most researched cathode form in microbial fuel cells, it is currently limited to the self-us...

AI Technical Summary

Problems solved by technology

The problems of this method are: 1. The manual brushing method will have large errors in the thickness of the air diffusion layer and the catalyst loading capacity made by different producers due to the difference in personal techniques and brushes, even if the same person has more than one There may be similar errors in the air cathode produced next time; 2. Using hydrophilic nafion solution as the binder of the catalyst cannot form a hydrophobic oxygen diffusion channel in the catalytic layer, thereby affecting the diffusion of oxygen in the catalytic layer; 3. The method of making air cathodes by brushing is time-consuming and labor-intensive, which leads to low production efficiency and is not conducive to large-scale industrial production

If the air electrodes used in microbial fuel cells do not have a unified and standardized manufacturing method, it will also cause great interference to the study of microbial flora, electrode materials, catalyst performance and other factors in microbial fuel cells.

Moreover, the vast majority of microbial fuel cells with stable performance are still using expensive noble metals as oxygen reduction catalysts, which is another bottleneck for the large-scale industrial application of microbial fuel cells.

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