Electrospinning Machine| Fluorine-doped micropore-covered mesoporous carbon nanofibers for long-lasting anode-free sodium metal batteries

Challenge: Sodium-based batteries are ideal for energy storage due to abundant raw materials and electrochemical performance similar to lithium-based batteries, but sodium metal anodes suffer from large volume changes and dendrite growth. Although anode-free sodium metal batteries can improve energy density, they face challenges such as poor cycling stability.

Approach: Prof. Xie Jia from Huazhong University of Science and Technology and Prof. Lu Jun from Zhejiang University collaborated to propose fluorine-doped microporous-covered mesoporous carbon fibers.

Innovation 1: Introducing electronegative fluorine generates more Lewis acid sites and sodium-philic Zn-Nx sites, suppressing electrolyte decomposition and promoting uniform sodium metal deposition. Structural modifications form a microporous-covered mesoporous framework, enabling a thin and uniform solid electrolyte interface for sodium confinement and self-smoothing.

Innovation 2: The carbon fiber current collector exhibits low sodium nucleation overpotential and rapid sodium thermal infusion, achieving highly reversible sodium plating/stripping at 5 mA cm−2 for over 5000 cycles with an average Coulombic efficiency of 99.93%.

Innovation 3: Anode-free pouch cells with high-loading cathodes retain 90% capacity after 200 cycles. Additionally, FMCNF demonstrates excellent performance in symmetric and full cells, enabling high sodium utilization and stable cycling, with assembled pouch cells achieving high energy density.
https://doi.org/10.1038/s41467-025-60168-8