RU214734U1 - Current collector of solid oxide fuel cell stack - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used in the manufacture of current collectors of solid oxide fuel cells (SOFCs). The technical result is to improve the efficiency of the SOFC battery due to better mixing of fuel and oxidizer, which is achieved by the fact that in the fuel and oxidizing channels of the current collector, located in a crossed configuration, their surface is made with a roughness of 40 microns along the entire length of the channels. Channels with the specified surface roughness can be made by pressing, electroerosive processing or in another way. When roughness is added to the channel walls, instead of laminar flows, turbulent flows are formed, which leads to an increase in the SOFC operation efficiency. 2 ill.

Description

The utility model relates to the field of electrochemistry, and more specifically, to conductive interconnectors of SOFC batteries of planar geometry. SOFC consists of a ceramic gas-tight electrolyte with high ionic conductivity with porous cathode and anode deposited on both sides. Through a system of gas channels, fuel and air are supplied separately and continuously to the porous SOFC electrodes. The fuel components and oxygen diffuse through the electrodes to the surface of the solid electrolyte, where electrochemical reactions occur at the three-phase gas-electrode-electrolyte interface. As a result, a potential difference arises between SOFC electrodes, which can be used in an external load. To increase the output power, individual SOFCs are combined into batteries. In SOFC batteries, current collectors are used for current collection, which also perform the function of separating and distributing gas flows. By changing the design of the current collector, it is possible to increase the characteristics of the battery. The technical result is aimed at increasing the efficiency of the SOFC battery.

US Pat. No. 4,640,876 describes a current collector design with gas channels in a co-directional configuration. This arrangement of fuel and oxidation channels creates additional difficulties for sealing gas spaces.

The current collector proposed in patent RU179208 U1 has the closest design. The gas flows are organized in a crossed configuration. Ceramic inserts are also used to seal the anode chamber. However, as the gas passes through the channels, the concentration of fuel and oxidizer near the three-phase boundaries decreases, thereby reducing the efficiency of the SOFC battery.

The technical result of the claimed utility model is the creation of a current collector design that makes it possible to increase the efficiency of the SOFC battery and improve energy performance by ensuring the uniformity of fuel and oxidizer flows along the entire length of the channel.

The claimed technical result is achieved by the fact that the current collector of the SOFC stack, which includes fuel and oxidizing channels in a crossed configuration, has a roughness (~40 μm) on the surface of the fuel and oxidizing channels along the entire length of the channel.

The proposed useful model of current collectors of the SOFC battery is illustrated by drawings, where

Fig. 1 shows a diagram of a component part of an SOFC battery with two current collectors and a fuel cell between them;

1 - current collector;

2 - fuel element;

3 - oxidative channels;

4 - fuel channels;

in fig. 2a - image of the channel without roughness;

in fig. 2b - image of a channel with roughness.

During the manufacturing process of the current collector (1), roughness (~40 μm) is created inside the oxidizing (3) and fuel (4) channels by pressing, electroerosive machining, or any other available method.

In the fuel (4) and oxidation (3) channels between the current collector (1) and the fuel cell (2), a laminar flow is created. Mixing inside such channels occurs only by diffusion. Diffusion mixing is not sufficient to uniformly provide reaction centers with reagents along the entire length of the channel. When roughness is added to the walls of the oxidizing (3) and fuel (4) channels (Fig. 2b), instead of laminar flows, turbulent flows are formed, which leads to better internal mixing of the flows, which, in turn, ensures uniform distribution of the fuel or oxidizer along the entire length channel.

The task of increasing the efficiency of the SOFC stack is solved by providing sufficient mixing of the oxidizer or fuel flow along the entire length of the channel. The use of SOFC battery current collectors with a rough channel surface will increase the efficiency of the SOFC battery without changing the dimensions of both the membrane-electrode unit and the SOFC battery as a whole. That is, with given weight and size characteristics, it will be possible to obtain the best energy performance, which is very important, since SOFC batteries are often used as mobile energy sources.

Claims (1)

A current collector of a stack of solid oxide fuel cells, including fuel and oxidizing channels in a crossed configuration, characterized in that the surface of the fuel and oxidizing channels has a roughness of ~40 μm along the entire length of the channel.

Images