This technology is a secondary battery separator that combines polymers containing polar functional groups with an aramid nanofiber framework that encapsulates them in a 3D lattice structure. It achieves an ultra-porous structure of over 95% and enhances affinity with electrolytes.
Conventional polyolefin separators have limited energy density due to low porosity and poor electrolyte wettability. In particular, they pose risks of short circuits caused by dendrite growth and thermal runaway when operating lithium metal batteries.
This technology involves coating a mixture of a polymer suspension and aramid nanoseeds, followed by a swelling process through protic solvent exchange and immersion in water to produce a composite membrane with macropores 140–700 nm in diameter. The polar functional groups of the polymer regulate electrolyte wettability and induce the formation of a stable fluorine-based SEI layer, which suppresses dendrite growth. Applicable as a separator for high-energy batteries using lithium metal anodes and high-power power tool cells, it reduces electrolyte impregnation time and minimizes short-circuit risks from high-temperature shrinkage thanks to its heat-resistant skeleton.
This invention was developed with support from the Ministry of Science and ICT for the development of 3D nano-skeleton materials applicable to negative electrodes and solid-electrolyte-interphase layers of lithium metal batteries, and in-depth research on suppressing dendrite formation.
WO2025-198302A1
