Air cathode without metal catalyst and preparation method thereof

Abstract

The invention relates to preparation of electrodes of fuel cells and aims at providing an air cathode without a metal catalyst and a preparation method thereof. The air cathode comprises a carbon cloth or a stainless steel mesh as a base material. Both sides of the base material are respectively coated by diffusion layers and catalyst layers, wherein the diffusion layers are contacted with the air and the catalyst layers are contacted with electrolyte. The cathode of the invention is composed of multiple diffusion layers and catalyst layers, reduces loss of water due to evaporation and improves stability of the electrodes. One side of the cathode directly faces the air and oxygen is directly diffused to the catalytic surface of the cathode without additional air supply devices and driving force, thus greatly lowering the operation cost of the cell and improving the stability. The catalytic materials of the cathodes are active carbons featuring wide sources and low prices, without any metal catalyst, thus greatly reducing the constructive cost. The air electrode has the characteristics of simple structure, low cost and easy expansion and can be used for producing microbial fuel cells with high properties and low costs and simultaneously purify waste water.

Description

technical field [0001] The invention relates to the electrode preparation of a fuel cell, in particular to a metal-free catalyst-free air cathode and a preparation method thereof. Background technique [0002] Microbial fuel cell is a new type of power generation device that uses microorganisms to catalyze the oxidation of biomass. It can use almost all organic matter, including various waste water such as domestic sewage, industrial waste water and animal waste, as fuel, and the treatment of waste water can realize energy recovery and purify sewage at the same time. It is considered to be an innovative technology with great application prospects. [0003] Using an air cathode, a single-chamber microbial fuel cell with a proton exchange membrane or without a membrane has been developed to make the battery compact and simple, especially the membraneless single-chamber battery. Because the expensive proton exchange membrane is removed, the battery manufacturing process is sim...

AI Technical Summary

Problems solved by technology

However, most single-chamber microbial fuel cells use metal platinum as the cathode catalyst with high electrocatalytic activity and good chemical stability. However, the high price and scarcity of metal platinum limit its wide application.

Transitional metal macrocyclic complexes, such as iron phthalocyanine (FePC) and tetraphenylphenyl (COTMPP), have oxygen reduction activity comparable to that of platinum, but their stability is not high, and the preparation process is complicated, and the cost price is still high

Other relatively cheap cathode catalytic materials such as manganese dioxide, iron ions and manganese ions have also been studied, but these materials are unstable and will dissolve into the solution after long-term operation, requiring regeneration or replacement, which not only complicates the operating process, but also Secondary pollution caused by the dissolution of metal ions

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