Combining the advantages of electrospun nanofibers with
surface modification to yield hybrid functional membranes has
provided a facile way to construct nanofibrous separators with
controllable pore structure. Herein hierarchical structured SiO2
nanoparticles (SiO2 NPs) coated PEI-PU composite nanofibrous
membranes, denoted as SiO2/PEI-PU, were for the first time
constructed by coating SiO2 NPs on PEI-PU nanofibrous membranes, which fabricated via electrospinning. Key to our development design is that the use of PEI endowed the as-prepared
composite membranes with not only improved safety but also
excellent affinity to liquid electrolyte. Benefiting from the
introduction of SiO2NPs, the SiO2/PEI-PU composite membranes
exhibit decreased average pore size, which is beneficial for
resolving thermal abuse tolerance and restraining the microshorting caused by the lithium dendrites, indicating a potential
application for acting as a first step toward high safety and
high-performance LIBs in the future.