Three-dimensional spatial plasticizing effect of star-shaped plasticizer for high-performance crosslinked solid...

Solid polymer electrolyte (SPE) among the most promising candidates for lithium metal battery (LMB) due to ease of processing and excellent electrode compatibility. However, balancing ionic conductivity and mechanical strength remains a key challenge. To address this, we designed and synthesized a star-shaped plasticizer using a straightforward thiol-acrylate photopolymerization process to enhance the overall performance of crosslinked SPEs. In this design, a thiol-based crosslinker forms the core, while oligomeric polyethylene glycol (PEG) chains extend as arms. This structure provides a rigid-flexible coupling framework, improving mechanical integrity while facilitating Li⁺ transport. The PEG arms enhance desolvation kinetics by coordinating with Li⁺, enabling smoother ion migration. Additionally, the plasticizer improves SPE/electrode interphase stability by promoting homogeneous Li⁺ distribution, enhancing interfacial compatibility. Benefiting from the wonderful merits of the plasticized SPE, the assembled LMB exhibits outstanding cycling performance, indicating the real value of this plasticizer in practical applications.