Аннотация:Over the past decades, there have been, although relatively slow, but profound transformations of the global energy consumption with an increase in the contribution of "unconventional current sources", primarily photovoltaics and wind energy. This leads to a radical change in the principles of the electric power industry, namely, the need to break the direct connection between its producers and consumers with the emergence of an intermediate link - devices for temporary storage of electricity in a different form, which can be converted back into electricity at the right time. This process has led to a rapid increase in the number of studies on the possible principles of such a temporary energy storage in the form of mechanical and chemical energy using numerous types of rechargeable electrochemical power sources. The review gives a brief description of the respective devices. The main attention is paid to redox flow batteries (RFB) - a promising type of energy storage devices capable of efficiently and economically operating in the distributed power grids in order to eliminate the imbalance between the rates of electricity production by "unconventional sources" and its consumption that change over time. At the constructive level, RFBs combine the principles of fuel cells and chemical energy sources (CES): transitions between electrical and chemical forms of energy in them occur as a result of oxidation and reduction of redox-active electrolytes, which are stored in separate containers and pumped through the electrode spaces of the membrane-electrode assembly (MEA) separated by a semi-permeable separator. This approach gives them a fundamental advantage over other types of CES - the ability to independently scale the energy capacity and power characteristics of the system. So far, numerous types of RFBs have been proposed, which differ in the electrochemical reactions occurring on their electrodes. This review provides a systematic description of all the main types of RFBs and analyzes their fundamental advantages and disadvantages in the context of the main characteristics that determine the prospects for using the RFBs in solving practical problems. Within the framework of this description, all types of RFBs are divided into three groups. The first includes classical RFBs, in which both electroactive components in each of the two redox states form true solutions and circulate in the circuits connecting the reservoirs with their main supply and the current generating unit, as a rule, the MEA battery. In such devices, only electrons cross the electrode / electrolyte interface, there are no material flows through it (for example, all vanadium RFB, polysulfide-halide PRB, or anthraquinone-bromine RFB). The second group, referred to in this review as "type I hybrid RFBs," is devoted to devices in which one of the participants in the main reaction in one redox state is in a separate phase and crosses the interface during the operation of the device (for example, zinc-bromine RFB or lithium flow batteries). Finally, the third group within the framework of this review is called "hybrid type II RFB". It is problematic to attribute them to the other two groups due to some fundamental differences (for example, RFB using semi-solid electrodes, RFB with several cells, P RFB with redox-mediator systems, etc.).