Next-Generation Liquid Metal Batteries Based on the Chemistry of Fusible Alloys

Abstract

With a long cycle life, high rate capability, and facile cell fabrication, liquid metal batteries are regarded as a promising energy storage technology to achieve better utilization of intermittent renewable energy sources. Nevertheless, conventional liquid metal batteries need to be operated at relatively high temperatures (>240 °C) to maintain molten-state electrodes and high conductivity of electrolytes. Intermediate and room-temperature liquid metal batteries, circumventing complex thermal management as well as issues related to sealing and corrosion, are emerging as a novel energy system for widespread implementation. In this Outlook, we elaborate the appealing features of fusible alloys-based liquid metals for energy storage devices and describe the metallurgical fundamentals, cost, and safety analysis of fusible alloys. Recent advances are discussed covering the rational screening of metallic alloys, interfacial engineering on the electrodes, and design of advanced electrolytes. In the end, we provide perspectives on current challenges and future opportunities in this field. This outlook not only aims to provide a design principle for high performance liquid metal batteries, but also inspires further development of novel energy systems beyond conventional solid-state batteries and high-temperature batteries.

Design Principles and Applications of Next‐Generation High‐Energy‐Density Batteries Based on Liquid Metals

“…[29] In the previous reports by Yu's group, comprehensively summarized tables of some commonly recognized fusible alloy systems that could possibly be used in batteries have been presented, with the melting temperature, reaction potentials, price, and safety hazards. [22,23] In Figure 2a, we present a summarization of the melting temperatures and estimated range of alloy melting temperatures by elements, versus the abundance of elements in the Earth's crust, labeled with the reduction potential, for an intuitive comparison. [4,[30][31][32] It could be clearly told that among these groups of fusible alloys, the alkali metal alloys obtain the lowest melting temperatures and reduction potentials, while the element abundance of them is the highest.…”

“…Recently, researchers reported the application of fusible alloys as a group of metal alloys maintaining liquid state near room-temperature, including alkali metals such as Na-K, Na-Cs alloys, and post-transition metals such as Ga-In, Ga-Sn alloys. [22][23][24] The adoption of room-temperature liquid metals in batteries has brought a bright new insight for the research works aiming to solve the interfacial issues of Li metal anodes. As summarized in Figure 1, in general, a dendrite-free liquid metal electrode based on fusible alloys could achieve higher energy and power density than insertion-based electrode materials.…”

Low-Temperature Multielement Fusible Alloy-Based Molten Sodium Batteries for Grid-Scale Energy Storage

“…Therefore, the Bi–Pb–Sn-based liquid metal battery is promising for the next-generation energy technologies provided the health issue related to Pb should be taken into consideration. 49 What’s more, given the lower cost of Pb and Sn than Bi, the demonstrated liquid metal battery based on Bi–Pb–Sn vs Na is also more cost-effective than the Na–Bi and Li–Bi systems in reported works. 16 …”

Recent Advances in Deformable Circuit Components with Liquid Metal

“…[ 88 ] Therefore, future work must be done to investigate how to translate liquid metal circuitry fabrication methods to large‐scale manufacturing processes that are both practical and cost‐effective. As liquid metal is significantly more expensive than conventional alternatives, [ 171 ] it is impractical for use if manufacturing processes require excessive amounts. For example, the expense of large amounts of liquid metal limits potential usage in cooling mechanisms for thermal management operation schemes.…”