TY - JOUR
T1 - Covalently crosslinked nanoconfinement strategy driven asymmetric flame-retardant gel electrolytes toward dendrite-free sodium metal batteries
AU - Chen, Suli
AU - Miao, Zhengrui
AU - Guo, Junhong
AU - Che, Haiying
AU - Ma, Zi Feng
AU - Liu, Tianxi
N1 - Publisher Copyright:
© 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
PY - 2026/7
Y1 - 2026/7
N2 - Gel polymer electrolytes hold significant promise for next-generation solid-state sodium metal batteries (SMBs) due to their high ionic conductivity and favorable interfacial contact with electrodes. However, their practical application is limited by inherent flammability, inferior mechanical properties, and poor interfacial compatibility with sodium metal anodes. Herein, we introduce a rationally designed covalently crosslinked nanoconfinement strategy to in situ build a mechanically robust asymmetric flame-retardant composite gel electrolyte (AFCGE) to achieve highly stable SMBs, where a chemically crosslinked covalent organic framework (COF) network is constructed on a glass fiber matrix along with synchronously polymerized flame-retardant polymers. The in situ formed COF network provides innate nanochannels that spatially confine polymer growth, which not only enhances mechanical robustness but also significantly promotes local Na+ transport kinetics and facilitates uniform sodium deposition at the anode side, thereby effectively suppressing dendrite growth. Thus, the AFCGE exhibits high ionic conductivity, excellent mechanical properties, superior flame retardancy, and outstanding interfacial stability. Na/Na symmetric cell achieves an ultralong cycling lifespan exceeding 4000 h with low polarization at 0.1 mA cm−2. Quasi-Solid-state SMBs further demonstrate excellent electrochemical performance, and no thermal runaway or electrolyte leakage occurs in pouch cells, underscoring their potential for safe and durable energy storage.
AB - Gel polymer electrolytes hold significant promise for next-generation solid-state sodium metal batteries (SMBs) due to their high ionic conductivity and favorable interfacial contact with electrodes. However, their practical application is limited by inherent flammability, inferior mechanical properties, and poor interfacial compatibility with sodium metal anodes. Herein, we introduce a rationally designed covalently crosslinked nanoconfinement strategy to in situ build a mechanically robust asymmetric flame-retardant composite gel electrolyte (AFCGE) to achieve highly stable SMBs, where a chemically crosslinked covalent organic framework (COF) network is constructed on a glass fiber matrix along with synchronously polymerized flame-retardant polymers. The in situ formed COF network provides innate nanochannels that spatially confine polymer growth, which not only enhances mechanical robustness but also significantly promotes local Na+ transport kinetics and facilitates uniform sodium deposition at the anode side, thereby effectively suppressing dendrite growth. Thus, the AFCGE exhibits high ionic conductivity, excellent mechanical properties, superior flame retardancy, and outstanding interfacial stability. Na/Na symmetric cell achieves an ultralong cycling lifespan exceeding 4000 h with low polarization at 0.1 mA cm−2. Quasi-Solid-state SMBs further demonstrate excellent electrochemical performance, and no thermal runaway or electrolyte leakage occurs in pouch cells, underscoring their potential for safe and durable energy storage.
KW - COF-based network
KW - Flame-retardant
KW - Flame-retardant gel electrolytes
KW - Interfacial stability
KW - Sodium metal batteries
UR - https://www.scopus.com/pages/publications/105035243281
U2 - 10.1016/j.jechem.2026.03.033
DO - 10.1016/j.jechem.2026.03.033
M3 - Article
AN - SCOPUS:105035243281
SN - 2095-4956
VL - 118
SP - 88
EP - 98
JO - Journal of Energy Chemistry
JF - Journal of Energy Chemistry
ER -