Wettable TiB2 Cathode for Aluminum Electrolysis: A Review

The present paper is devoted to obtaining new fundamental data on the electrochemical behavior of oxygen-evolving anodes in fluoride-oxide melts. In this work, the function of platinum and basics of its anode behavior as an ideal oxygen-releasing anode during electrolysis of the low-temperature KF-AlF3-Al2O3-based melt were studied by potentiometric, cyclic voltammetric, and chronopotentiometric methods. The influence of the electrolyte composition, temperature, atmosphere, potential sweep rate, current density on the kinetics of the anode process was investigated. In order to clarify the mechanism of the process under study, electrolysis testing was carried out to inform an analysis of platinum oxidation products. Based on the experimental results, the validity of an earlier proposed scheme of the anode process on platinum when carrying out electrolysis of low temperature KF-AlF3-Al2O3 based melts was confirmed. Results will be used for theoretical modeling and studying the kinetics of the anode process on an over oxygen-evolving anodes in the fluoride-oxide melts.

“…Taking into account the above results and discussion, the scheme of the anode process on Pt in KF-AlF 3 -Al 2 O 3 melts includes chemical equilibrium (9) and below reactions:…”

Section: Comentioning

confidence: 97%

mentioning

confidence: 99%

Anode Process on Platinum in Low Temperature KF-AlF₃-Al₂O₃ Based Melts: An Update

Suzdaltsev¹,

Zaikov²

2023

“…And titanium diboride is considered a promising material for wettable cathodes in aluminum electrolysis. 65,125 Yang et al studied the wettability of coating in molten aluminum electrolysis system and found that the wettability of TiB 2 coating and aluminum liquid was better than that of graphite cathode carbon block and aluminum liquid. 126 The better the molten salt wets the material, the greater the critical current density.…”

Section: Ionic Radiusmentioning

confidence: 99%

Influencing Factors and Challenges on the Wettability of Electrode in Molten Salt

Kong,

Su,

et al. 2024

Molten salts play an important role in the electrolysis of solid metal compounds, especially oxides and sulfides, and have an impressive storage capacity and power, so they are now the electrolyte for many new types of rechargeable batteries. Unfortunately, due to the high viscosity and high surface tension of molten salt, the unsatisfactory wettability of electrode and molten salt restricts the development of molten salt electrochemistry. In the past half century, research on interface phenomena has been devoted to establishing more accurate models for measuring surface tension and wetting angle, developing more scientific wetting angle measurement techniques, and exploring the influencing factors of wettability. Different from a water solution interface, molten salt experiment are performed in high temperature and pressure environments, making it difficult to test the wetting angle, and there has been little research on the interface phenomenon of molten salt. In this Review, on the basis of existing models and experimental data, the factors and mechanisms that lead to the difference of wettability between melt and solid matrix in molten salt systems are analyzed in detail. Finally, we put forward the prospects and suggestions for the study of the wettability of melt to solid substrate in molten salt.

“…123 The wetting of TiB 2 by Al liquid depends on the relative density and purity of TiB 2 material and interaction temperature. 7 Heidari et al reported that the aluminium wettability of TiB 2 is proportional to the interaction temperature. 124 At 870 °C under vacuum, no visible wetting of TiB 2 by Al was observed.…”

Section: Tib 2 Based Cathodesmentioning

confidence: 99%

“…As TiB 2 is deemed highly expensive, trials have been made to use TiB 2 coatings on various substrates to examine the adhesiveness of the TiB 2 layer. 7 This paper summarises the developments in inert anodes technology and will discuss anode materials such as metals, ceramics and cermets. A brief discussion will be provided on low-temperature electrolytes potentially used in aluminium electrolysis and their properties, such as electrical conductivity and alumina solubility.…”

mentioning

confidence: 99%

Review—Primary Production of Aluminium with Oxygen Evolving Anodes

Padamata

Singh

Haarberg

et al. 2023

Self Cite

Due to environmental and economic concerns, carbon-free aluminium production has been an ultimate goal for aluminium industries. For the past few decades, a considerable amount of research has been conducted to find an inert anode material that could replace the consumable carbon anodes for aluminium electrolysis. Anodic materials such as metals, ceramics, and cermets have been studied extensively. All these anode materials have their advantages and disadvantages. However, metal alloys have proven effective because of their resistance to high-temperature corrosion and their ability to produce a protective oxide layer. For a successful adaptation of metallic anodes into the aluminium electrolysis cell, an electrolyte with a low operating temperature and high alumina solubility with good electrical conductivity is required. A wettable cathode with a shorter anode-to-cathode distance is preferred to compete with the Hall-Héroult process in terms of energy requirements. This review discusses the research progress on inert anodes, wettable cathodes, and electrolytes.