Core-Shell Hybrid Nanowires with Protein Enabling Fast Ion Conduction for High-Performance Composite Polymer...

Incorporating nanofillers is one of the promising approaches for simultaneously boosting the ionic conductivity and mechanical properties of solid polymer electrolytes (SPEs). However, effectively creating faster ion-conduction pathways via nanofillers still remains a big challenge. Herein, core-shell protein-ceramic nanowires for more efficiently building fast ion-conduction networks in SPEs are reported. The core-shell protein-ceramic nanowires are fabricated via in situ growth of protein coating on the electrospun TiO₂ nanowires in a subtly controlled protein-denaturation process. It is demonstrated that the core-shell protein@TiO₂ nanowires effectively facilitate ion-conduction. As a result, the ionic conductivity, mechanical properties, electrochemical stability, and even Li⁺ transference number of the SPEs with core-shell protein@TiO₂ nanowires are significantly enhanced. The contributions from the 1D morphology of the protein@TiO₂ nanowires, and more importantly, the favorable protein structure for further promoting ion-conduction at the polymer-filler interfaces are analyzed. It is believed that the protein plays a pivotal role in dissociating lithium salts, which benefits from the strong interactions between protein and ions, making the protein serve as a unique "natural channel" for rapidly conducting Li⁺ . This study initiates an effective method of promoting ionic conductivity and constructing faster ion-conduction networks in SPEs via combining bio- and nanotechnology.