Solvation Modulation and Reversible SiO₂-Enriched Interphase Enabled by Deep Eutectic Sol Electrolytes for Low-Temperature Zinc Metal Batteries

Zinc metal batteries (ZMBs) hold great promise for large-scale energy storage in renewable solar and wind farms. However, their widespread application is hindered by poor stability and unsatisfactory low-temperature performance, attributed to issues such as dendrite formation, strong Zn2+-H2O coordination, and electrolyte freezing. Herein, a deep eutectic sol electrolyte (DESE) is proposed by mixing SiO2 nanoparticles with a solution composed of 1,3-dioxolane (DOL) and Zn(ClO4)(2)6H(2)O for stable low-temperature ZMBs. By substituting the strong Zn2+- H2O coordination with favorable Zn2+-DOL coordination, the DESE exhibits exceptional antifreezing capability at temperatures beyond -40 degrees C. The formation of Si-O-Zn2+ bond near SiO2 nanoparticles further improves the low-temperature performance of the DESE by decreasing Zn2+ desolvation energy. Moreover, the SiO2 nanoparticles co-plating/co-stripping with Zn metal, forming a reversible and homogeneous SiO2-enriched interphase to protect the Zn anode from dendrite growth and interfacial side reactions. Remarkably, the DESE-based ZMB full cells exhibit significantly prolonged cycle life of 8000 cycles at 1 A g(-1) at 25 degrees C and 700 cycles at 0.2 A g(-1) at -40 degrees C. This work provides a promising strategy to design advanced electrolytes for practical low-temperature ZMBs.