Nuclear Science and Techniques ›› 2019, Vol. 42 ›› Issue (3): 30501-030501.doi: 10.11889/j.0253-3219.2019.hjs.42.030501

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Effect of size on the electrolytic performance of solid oxide electrolysis cell

Quan HOU1,2,Chengzhi GUAN1,Guoping XIAO1,Jianqiang WANG1(),Zhiyuan ZHU1   

  1. 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-05-01 Revised:2018-09-16 Online:2019-03-10 Published:2019-04-18
  • Contact: Jianqiang WANG E-mail:wangjiangqiang@sinap.ac.cn;wangjianqiang@sinap.ac.cn
  • About author:<named-content content-type="corresp-name">HOU Quan</named-content>, male, born in 1989, graduated from China University of Mining and Technology in 2013, doctoral student, focusing on high temperature electrolysis|<named-content content-type="corresp-name">HOU Quan</named-content>, male, born in 1989, graduated from China University of Mining and Technology in 2013, doctoral student, focusing on high temperature electrolysis|WANG Jianqiang, E-mail:<email>wangjiangqiang@sinap.ac.cn</email>
  • Supported by:
    Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA02050100);Supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA02050100)

Abstract: Background

The solid oxide electrolysis cell (SOEC) stack is the core reactor of the high temperature water vapor electrolysis hydrogen production system (HTSE), which consists of several single SOECs in series. The size of the single cell restricts the electrochemical hydrogen production performance per unit area of the SOEC stack, which affects the complexity and cost of the HTSE hydrogen system.

Purpose

This study aims to investigate the effect of the electrolytic cell size on cell reaction characteristics.

Methods

Based on the computational fluid dynamics software, a three-dimensional model of the electrolytic cell was established. The cell dimensions of 4 cm×4 cm, 8 cm×8 cm and 16 cm×16 cm were taken as objects for detailed analysis.

Results

The results show that the cell size has little effect on the electrolytic performance when the working voltage is less than the thermal neutral voltage. When the water vapor content in the reactant is 70%, the electrolytic current density for an electrolytic cell with an effective area of 16 cm×16 cm, can reach 8 033 A·m?2 at an electrolysis voltage of 1.34 V and the uniformity of temperature and current density distribution in the electrolytic cell has improved.

Conclusion

When working voltage is higher than the thermal neutral voltage, the larger the electrolytic cell size, the greater the electrolytic current density. However, the uniformity of the temperature and current density distribution in SOEC deteriorates, and there is a clear gradient distribution as the size increases. By appropriately reducing the H2O reaction ratio, the temperature and current density gradients caused by the increase in size can be overcome.Key words High-temperature steam electrolysis, Solid oxide electrolysis cell, Cell size, Three-dimensional model, Computational fluid dynamics