Strategic alloy design for liquid metal batteries achieving high performance and economic stability

Liquid metal batteries (LMBs) trigger strong interest due to their longevity, low cost, high safety, and scalability. However, reliance on a single metal cathode, such as Sb, which experiences a substantial price increase of 189.14 % over the past decade, poses challenges for sustainable energy storage. Additionally, single metal typically attends to one aspect and loses another. Sb offers high voltage, but encounters high temperature and unstable cycling; Bi empowers good cycle while falls short in energy density; Sn or Pb could reduce the melting point but suffers from low voltage. To leverage the strengths of each metal, we combine Sb, Bi, Sn and Pb to design ternary and quaternary alloy cathodes. The resultant Li || SbBiSnPb cell demonstrates outstanding overall performance with nearly 70 % capacity retention at 1000 mA cm⁻², and stable cycling with no capacity decay during 344 cycles. Furthermore, the price of multi-metal alloy fluctuates 2–3 times less than that of pure Sb, indicating that alloying can effectively evade the dependence on single metal and ensure a stable and flexible material supply. This preliminary investigation establishes a foundation for development of preferable alloy electrodes and offers prospects for high-performance LMBs in grid-scale energy storage.