In aluminum electrolysis, carbon anodes fulfill dual functions: providing electrical conductivity and participating in electrochemical reactions. However, these anodes face challenges such as cracking and degradation, which adversely affect their performance and longevity. Consequently, improving the quality of carbon anode is crucial to enhancing the production efficiency of electrolyzers. Key properties, including porosity and air permeability, significantly influence anode consumption and durability. This study presents the development of carbon anodes with reduced porosity and air permeability through optimized forming, sintering, and doping processes. Results revealed that using powdered pitch as a binder led to higher densification, improved flatness, and reduced porosity. Molding under a pressure of 20 MPa for 45 min further enhanced anode quality. Sintering reduced layer spacing and increased graphitization, with optimal conditions determined to be 1100 ℃ for 45 min. These conditions produced carbon anodes with maximum bulk density, minimum resistivity, and an air permeability of 2.54 nPm. The introduction of fusible B₂O₃ effectively sealed internal pores, coated the carbon substrate surfaces, and formed a protective film. This innovation reduced air permeability to 2.05 nPm and significantly enhanced the oxidation resistance of the anodes. These findings provide valuable insights into the production of high-performance carbon anodes, contributing to improved efficiency in aluminum electrolysis.

Optimized fabrication and enhanced performance of low-porosity carbon anodes for aluminum electrolysis
    Abstract
    1 Introduction
    2 Material and methods
        2.1 Experimental materials and preparation
        2.2 Characterization method
    3 Results and discussion
        3.1 Effect of pitch addition form on the microstructure and properties of carbon anode
        3.2 Effect of molding conditions on the properties of carbon anodes
        3.3 Graphitization analysis of carbon anode
        3.4 Effect of B2O3 doping on the properties of carbon anode
    4 Conclusion
    Acknowledgements 
    References

• Fan Bai(School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China)
• Guifang Xu(School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China)
• Andong Wang(School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China)
• Caifeng Chen(School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China) Corresponding author