# Developing a Novel Design for a Tubular Solid Oxide Fuel Cell Current Collector
###### Abstract
It is regarded as the most significant component since it is in charge of transferring fuel and oxygen across the active portion of the cell, collecting the created electrons from the cell, and putting the cell components together. It should be thermally and mechanically stable and have a thermal expansion coefficient that matches those of the anode and cathode [8]. Additionally, the current collector should be able to cope with the anode and cathode requirements described previously. Therefore, the current collector should have a unique design to supply the fuel and oxygen to the reaction sites while achieving the maximum cell performance. The current collector is also responsible for the uniform distribution of the flow inside the cell and stabilizing the cell's temperature [9; 10]. It is important to design the current collector to enable it to draw the generated current from the cell with the lowest possible losses. For planar SOFCs, several previous studies have focused on the current collector's design and reached different optimal designs that fulfilled the current collector's requirements [11; 12; 13; 14; 15]. For tubular SOFCs, it is difficult to determine the optimal current collector configuration, and several previous studies have focused on this topic. [PERSON] et al. [16] developed a new configuration for the current collector for a stack of fuel cells, and this new design increased the airflow among the cell tubes. The problem with this design is that it only worked for a stack of cells. [PERSON] et al. [17] developed a current collector that could collect the generated current from the cell while simultaneously fusing two cells together. The non-uniform distribution of the air and fuel is a problem with this design because it has no guides for the flow inside the cell. [PERSON] et al. [18] developed a mathematical model to study the effect of axially distributed air and fuel on a tubular SOFC's performance. They found that the performance can be greatly enhanced by the uniform distribution of both air and fuel. [PERSON] et al. [19] compared three different modes of the current collector: inlet current collector, outlet current collector, and inlet-outlet current collector for tubular SOFCs. The results showed that the inlet-outlet current collector was the best choice based on cell performance. [PERSON] et al. [20] connected a tubular SOFC with an aluminum tube on both sides to collect the current from the cell. The problem with this method is that it could not achieve a uniform distribution of air and fuel throughout the cell. [PERSON] et al. [21] developed a current collector mesh that contains a microchannel to uniformly distribute the air and fuel throughout the cell. [PERSON] et al. [22] developed a method for current collection from a tubular SOFC in the form of wires that wrapped around the cell perimeter. The problem of the non-uniform distribution of the air and fuel was not solved in this way. [PERSON] et al. [23] developed a new method of current collection in the form of metallic wires that touched the cell's surface and were used to collect the current from the cell. [PERSON] et al. [24] developed a new design for a current collector to be used in a \(\mu\)-tubular SOFC. This design was adapted from the heat exchanger design developed by CALGAVIN Ltd. It was mainly based on increasing the contact surface area of the electrodes to increase the cell's current collection and performance. They achieved a peak power density 4.3 times  
Figure 1: Solid oxide fuel cell: (**a**) tubular configuration; (**b**) planar configuration. higher than that of the conventional design. The problem with this design is its complexity, which leads to high manufacturing costs compared to traditional designs. [PERSON] et al. [25] studied the use of metal wire brushes as current collectors. They investigated the use of brushes made of different materials, including stainless steel and copper-zinc. The copper-zinc brush showed a higher performance compared to the stainless steel one.