Medium-temperature molten sodium batteries with aqueous bromine and iodine cathodes

Toward Sustainable Metal-Iodine Batteries: Materials, Electrochemistry and Design Strategies

Due to the natural abundance of iodine, cost-effective, and sustainability, metal-iodine batteries are competitive for the next-generation energy storage systems with high energy density, and large power density. However, the inherent properties of iodine such as electronic insulation and shuttle behavior of soluble iodine species affect negatively rate performance, cyclability, and self-discharge behavior of metal-iodine batteries, while the dendrite growth and metal corrosion on the anode side brings potential safety hazards and inferior durability. These problems of metal-iodine system still exist and need to be solved urgently. Herein, we summarize the research progress of metal-iodine batteries in the past decades. Firstly, the classification, design strategy and reaction mechanism of iodine electrode are briefly outlined. Secondly, the current development and protection strategy of conventional metal anodes in metal-iodine batteries are highlighted, and some potential anode materials and their design strategies are proposed. Thirdly, the key electrochemical parameters of state-of-art metal-iodine batteries are compared and analyzed to solve critical issues for realizing next-generation iodine-based energy storage systems. Therefore, the aim of this review is to promote the development of metal-iodine batteries and provide guidelines for their design.

Rechargeable Seawater Batteries-From Concept to Applications

Harvesting energy from natural resources is of significant interest because of their abundance and sustainability. Seawater is the most abundant natural resource on earth, covering two-thirds of the surface. The rechargeable seawater battery is a new energy storage platform that enables interconversion of electrical energy and chemical energy by tapping into seawater as an infinite medium. Here, an overview of the research and development activities of seawater batteries toward practical applications is presented. Seawater batteries consist of anode and cathode compartments that are separated by a Na-ion conducting membrane, which allows only Na⁺ ion transport between the two electrodes. The roles and drawbacks of the three key components, as well as the development concept and operation principles of the batteries on the basis of previous reports are covered. Moreover, the prototype manufacturing lines for mass production and automation, and potential applications, particularly in marine environments are introduced. Highlighting the importance of engineering the cell components, as well as optimizing the system level for a particular application and thereby successful market entry, the key issues to be resolved are discussed, so that the seawater battery can emerge as a promising alternative to existing rechargeable batteries.