Thermodynamic and Electrochemical Investigations of Potassium–Antimony Alloys

In September 1975, the head of Russian electrochemists, Academician A.N. Frumkin (1895–1976), in his report at the XI Mendeleev Congress on General and Applied Chemistry (Alma-Ata) “Some Problems of Electrochemistry”, which went down in the history of science under the title “A word about the benefits of electrochemistry”, noted that the creation of new chemical current sources (CCS) is one of the most important tasks of applied electrochemistry. He saw a special prospect for their creation in the wide use of alkali metals and their alloys. Referring electrochemistry to the number of branches of chemical physics, A.N. Frumkin at the same time emphasized the closest connection between electrochemistry and chemical thermodynamics. He pointed out that “... at creating chemical sources, the main task is to reduce the deviation of the state of a operation system from equilibrium conditions.” Proceeding from this task, it seems to expedient in the published reviews to combine the presentation of thermodynamic and electrochemical studies of any system. More than 45 years have passed since the report of A.N. Frumkin. Lithium-ion batteries have been widely used since 1991. For the first time in the 120 years of the Nobel Prizes in Chemistry, the 2019 Nobel Prize was awarded for ground breaking work into the electrochemistry of lithium, leading to the creation of lithium-ion batteries (LIBs). In the 21st century, a huge number of works have been published aimed at improving them, searching for and studying new anode and cathode materials for them. Already in the first decade of the 21st century, active research began on sodium-ion batteries (SIBs). Later, since 2015, potassium-ion batteries (PIBs) have been intensively studied in a number of countries. Progress has been made in creating rechargeable batteries based on alkali metal (Li, Na, K)–chalcogen (S,Se) systems suitable for operation at room temperature. Among the promising materials for the negative electrode (anode) are antimony, its alloys, compounds and composites. This review is devoted to alloys of the potassium–antimony system, their thermodynamic properties in solid and liquid states, and electrochemical behavior in various media. Some examples of the use of antimony and its compounds in potassium-ion batteries are reported. At the same time, the focus is on large reviews of the most recent years (2020 and 2021) and some typical experimental studies (2019–2021).