Citation: Antipov, A.; Pichugov, R.; Abunaeva, L.; Tong, S.; Petrov, M.; Pustovalova, A.; Speshilov, I.; Kartashova, N.; Loktionov, P.; Modestov, A.; et al. Halogen Hybrid Flow Batteries Advances for Stationary Chemical Power Sources Technologies. Energies 2022, 15, 7397. https://doi.org/10.3390/en15197397 Academic Editor: Roberto Bubbico Received: 9 September 2022 Accepted: 5 October 2022 Published: 9 October 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Review Halogen Hybrid Flow Batteries Advances for Stationary Chemical Power Sources Technologies Anatoly Antipov 1, * , Roman Pichugov 1 , Lilia Abunaeva 1 , Shengfu Tong 2, *, Mikhail Petrov 1 , Alla Pustovalova 1 , Ivan Speshilov 1 , Natalia Kartashova 1 , Pavel Loktionov 1 , Alexander Modestov 3 and Artem Glazkov 1 1 EMCPS Department, Mendeleev University of Chemical Technology of Russia, 125047 Moscow, Russia 2 Sustainable Energy Materials and Science, Jinhua Advanced Research Institute, Jinhua 321019, China 3 Electrocatalysis Laboratory, The Institute of Physical Chemistry and Electrochemistry RAS, 119071 Moscow, Russia * Correspondence: 89636941963antipov@gmail.com (A.A.); shengfutong@gmail.com (S.T.) Abstract: This review aims to highlight the current advances in hybrid redox flow battery (HRFB) technology, encompassing one of the best combinations of efficiency, cost and flexibility due to its module construction, which offers independent scaling of power density and energy capacity. This work emphasizes the interest of the scientific community both in (i) studying the properties and principles of HRFB operation in order to improve commonly proposed systems, and in (ii) the development of energy storage devices with new reagent types or RFB concepts. The data provided enhances the reader to conclude whether novel concepts in halogen oxidizers utilization could help to overcome the problem of insufficient power and energy densities of common RFB. Keywords: hybrid flow batteries; zinc-bromine flow batteries; hydrogen-bromate flow batteries; halogen electrolytes 1. Introduction The well-known 17 Sustainable Development Goals (SDGs) are at the hearing today to form the 2030 ecological agenda majors [1]. Among them, the reliable technologies to provide energy in a sustainable way are limited by insufficient usage of renewable energy sources. Due to the intermittent availability of the latter, the demand for effective energy storage systems (ESS) today is of crucial importance. The distributed energy resources (DER) model is another ace in the hole that offers more flexible and integrative energy storage mechanisms within the local power grid close to the end user, thus minimizing the demand for power transmission lines usage [2]. An essential solution to the problem of energy accumulation and storage in distributed networks is the use of chemical power sources (CPS). Among the most effective energy systems for stationary applications, a special place is occupied by redox flow battery (RFB) technology, encompassing easy scalability with independent scaling of power density and energy capacity, no detrimental effects of a deep discharge, very low self-discharge, low cost for a large system compared to other types of batteries, and long cycle life [3]. However, the wide distribution and commercialization of flow batteries are currently hindered by their insufficient energy capacity and power, primarily due to the low energy density of reagents used [4]. To achieve significant capacity, the electrolyte tanks have to be large enough, along with the aqueous electrolyte, which often makes the battery very heavy and suitable only for stationary applications. Hybrid flow batteries (e.g., zinc-bromine, zinc-cerium, zinc-iron, iron-iron), which have a liquid-solid electrochemical reaction, are prone to additional degradation due to dendrite formation and increased resistance, while the common all-liquid systems such as vanadium and polysulfide bromide often require Energies 2022, 15, 7397. https://doi.org/10.3390/en15197397 https://www.mdpi.com/journal/energies