Dual-Active Ca-Li Alloy Anodes Enable Ultra-Stable and Ultra-Low-Cost Liquid Metal Batteries

Abstract

Liquid metal batteries (LMBs) have emerged as a promising technology for large-scale energy storage owing to their intrinsic safety, long cycle life, and low manufacturing cost. However, achieving further reductions in system-level cost remains challenging. We report a cost-effective Ca-Li||Pb LMB coupling a dual-active Ca-Li anode with inexpensive Pb cathode. Synergy with a dual-cation CaCl2-LiCl (35:65 mol%) electrolyte enhances cycling stability. In-situ EIS analysis reveals a unique discharge pathway: initial formation of CaLiPb followed by conversion to CaPb3 and LiPb. This sequence reshapes the voltage profile. Crucially, the molten LiPb phase redistributes, forming conductive networks that boost electrode kinetics. Consequently, an Ah-level battery achieves stable cycling at 100 mA/cm2 with a record-low electrode cost of 66.18 $/kWh among all reported Ah-level LMBs. This work demonstrates a new high-performance, low-cost liquid metal battery architecture and provides fundamental design principles for next-generation economical grid-scale energy storage.