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

Abstract

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)2·6H2O 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 °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 °C and 700 cycles at 0.2 A g−1 at ‐40 °C. This work provides a promising strategy to design advanced electrolytes for practical low‐temperature ZMBs.