Harnessing Supercooled Liquid Sulfur for Enhanced Electrochemical Performance in Nanoporous Metal-Based Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are promising candidates for next-generation energy storage, yet challenges in controlling sulfur phase behavior hinder their performance. Recent discoveries of supercooled liquid sulfur have opened innovative avenues for regulating sulfur oxidation chemistry. Here, we establish a mechanistic understanding of liquid sulfur formation and its impact on electrochemical performance. Guided by ab initio calculations, we identify an optimal substrate binding energy range─exemplified by Ni, Pt, and Au─that stabilizes liquid sulfur at room temperature. In situ optical microscopy reveals distinct sulfur evolution across nine conductive substrates, confirming the critical role of interfacial interactions. Leveraging these insights, we design a bicontinuous three-dimensional nanoporous nickel (np-Ni) electrode that enables uniform and reversible liquid sulfur deposition. Electrochemical evaluations demonstrate np-Ni achieves markedly improved redox kinetics and discharge capacity compared to graphene-coated and commercial Ni counterparts. This work provides a fundamental framework for integrating liquid sulfur into high-performance LSBs.