In 2019, the Nobel Prize in Chemistry was awarded for “the development of lithium-ion batteries”. John Goodenough (USA), Stanley Wittengham (USA) and Akira Yoshino (Japan) became the laureates of the prize for the research carried out 35-45 years ago, in 1975-1985. Their work in the field of reversible intercalation of lithium ions into layered structures served as the basis for the creation of lithium-ion batteries, the production of which began in 1991. In the next almost thirty years, in many hundreds of works, there were various new anode and cathode materials, electrolytes proposed for this class of rechargeable sources. In the 21st century, based on the same principles, large-scale studies of sodium-ion batteries began. Since about 2012, there has been a steady interest in magnesium-ion batteries. In 2015, a number of studies of potassium-ion batteries appeared, the number of works devoted to them began to grow rapidly (China, USA, Australia, Republic of Korea, etc.). At the same time, in the second decade of the 21st century, rechargeable batteries for room temperature, built according to a different principle, became the focus of active studies: they were based on the alkali metal-chalcogen or alkali metal-oxygen systems. In this small review, we attempted to briefly describe the studies of rechargeable power sources involving potassium actively carried out in the most recent years (2017-2019). In view of the large number of experimental studies, the research was mainly based on the review papers of these years.