Abstract
Commercial lithium-ion batteries that use liquid electrolytes suffer from limitations in energy density and face significant safety concerns. The adoption of quasi-solid-state electrolytes, particularly when paired with high-voltage cathodes and high-capacity anodes, offers a promising approach to address these issues. Among these, in situ polymerized gel electrolytes have garnered considerable attention due to their excellent interfacial contact with electrodes and facile fabrication process. However, constructing in situ polymerized quasi-solid-state lithium batteries that simultaneously achieve high energy density and enhanced safety remains a significant challenge. Key obstacles include the strong oxidation of high-voltage cathodes, poor interfacial stability with high-capacity anodes, and the inherent safety risks associated with high-energy-density lithium batteries. Therefore, there is an urgent need to develop innovative solutions to overcome these challenges. This review provides a comprehensive summary of recent progress in this field. In addition, future perspectives on the development of high-energy-density, safe lithium batteries prepared via in situ polymerization are discussed.