Novel supramolecular polymers for advanced applications in lithium metal batteries
The rapidly increasing demand for electric vehicles and large-scale energy storage has driven intense interest in lithium metal batteries (LMBs) because of their ultrahigh theoretical energy density. However, their practical application is hindered by unstable lithium metal interfaces, dendrite growth, and severe polysulfide shuttling when paired with sulfur cathodes in Li-S battery. In his thesis, Yongsheng Zhang explores supramolecular polymers as a versatile platform to address these challenges across multiple components of LMBs.
By leveraging diverse supramolecular interactions, Zhang rationally designed a series of supramolecular polymer systems and applied them as solid electrolytes, lithium anode protective layers, and separator modification materials. He also presents a series of thiourea-based poly(ether-thiourea) solid electrolytes. These materials exhibit high thermal and electrochemical stability, tunable mechanical properties, and enhanced ionic conductivity enabled by thiourea-anion interactions that promote lithium salt dissociation. Furthermore, he applied the same polymer as an adaptive protective layer for lithium metal anodes, where its viscoelastic and ion-regulating behavior effectively suppresses dendrite growth, improves interfacial stability, and enhances battery cycling performance.
To further improve solid polymer electrolyte performance, Zhang introduces a dual-engineering strategy combining inductive fluorination and metal-organic frameworks fillers. The resulting composited electrolyte demonstrates high ionic conductivity, increased Li+ transference number, and long-term stable cycling. Finally, Zhang develops a multifunctional separator modification using complex coacervate core micelles to effectively suppress polysulfide shuttling, enabling excellent long-term cycling stability in Li-S batteries.
Overall, this work establishes supramolecular polymer engineering as a powerful strategy for advancing safer and higher-performance lithium metal batteries.