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.