The role of nanoceramic additives surface charge on the ionic transport of single lithium-ion conducting polymer electrolytes

In the context of designing solid polymer electrolytes for reliable, efficient, and durable lithium batteries, the present study was developed to have a better understanding of the role of the surface charge of ceramic nanoparticles, on the ionic transport used as additives in single lithium-ion conducting polymer electrolytes. A polymer based on sp(3) boron with polyethylene glycol (with an average Mn = 400 g mol(-1)) bridges was used as a model system; SiO2, ZrO2, and TiO2 nanoparticles (NPs), having a negative, neutral, and positive effective surface charge, respectively, were incorporated during synthesis. Samples were characterized by XRD and EIS; a DRT analysis of impedance spectra was also performed. The results obtained showed that the electrostatic interactions of Li+ with the surface charge of nanoceramics resulted in an enhancement of 2.5% of ionic conductivity for the TiO2-containing polymer with respect to the electrolyte without NPs (due to repulsion between Li+ and nanoceramics surface. The sample with ZrO2, compared to the NP-free polymer showed a similar conductivity and a decreased conductivity of 1.2% with respect to the NP-free polymer for the SiO2 case (due to attraction between Li+ and nanoceramics surface, that anchors Li+, hindering its transport). The pseudo-activation energy values (from VTF plots) indicated no change in the transport mechanism for all samples.