Solid-state polymer electrolytes (SPEs) are attracting significant attention for enabling high-energy-density and high-safety lithium-metal batteries due to their low interfacial impedance, excellent electrode compatibility, and outstanding mechanical flexibility.

However, problems such as low room-temperature ionic conductivity, limited Li⁺ transference number, and insufficient mechanical strength have long constrained the practical application and industrialization of solid-state batteries.

Associate Professor Gao Guoxin's team from the School of Chemistry at Xi'an Jiaotong University (XJTU) recently overcame this difficulty, proposing an innovative strategy of a "multi-level porous aramid nanofiber-supported dual-crosslinked polymer network".

The team copolymerized small molecule monomers to construct a polymer network with short ether chains as side chains, solving the issue of ether-based polymers easily crystallizing at room temperature.

At the same time, using hydrogen bond self-assembly technology, they created an aramid nanofiber aerogel with multi-level pores. This special structure anchors anionic groups to inhibit battery polarization and opens up continuous and fast transmission channels for Li⁺.

The two polymer networks achieve functional synergy through three-dimensional interpenetration. The resulting solid-state electrolyte reached the key technical indicator of 10⁻⁴ S cm⁻¹ room-temperature ionic conductivity.

This innovative structure also promotes the formation of an "organic-rich/inorganic-rich bilayer solid-state electrolyte interphase (SEI film)" at the lithium metal and electrolyte interface. While improving interfacial compatibility, it also achieves uniform lithium deposition and stripping, avoiding the safety hazards caused by lithium dendrite growth.

This electrolyte allowed the assembled full battery to achieve more than 1,000 stable charge-discharge cycles in a room temperature environment, with its performance reaching an advanced level in the industry.

The research results, titled Hierarchically Aligned Aramid Nanofiber Aerogel Framework Enhances Ionic Transport and Interfacial Stability of Solid-State Lithium-Metal Batteries, have been published in Advanced Functional Materials.