Effect of graphene oxide particles on space charge accumulation in LDPE/GO nanocomposites

This paper focuses on the space charge characteristics of low-density polyethylene (LDPE)/ graphene oxide (GO) nanocomposites, as well as the corresponding trap level distributions. The relative permittivity, DC conductivity, DC breakdown strength and space charge behaviors of nanocomposites with GO filler content of 0, 0.001, 0.005, 0.01, 0.05, and 0.1 wt% were studied. The trap level distributions were investigated using the isothermal discharge current (IDC) method. The experimental results show that the 0.01 wt% LDPE/GO nanocomposites have a significantly lower relative permittivity, a lower DC conductivity, a higher breakdown strength and a smaller amount of space charge accumulation than that of the neat LDPE. With increased GO content, the space charge accumulation of the nanocomposites shows an increasing trend. It is indicated that the certain content of GO nanoparticles could introduce large quantities of deep carrier traps, which suppress the transport of charge carriers and further restrain the space charge injection and accumulation. The experimental results reveal that the GO nanoparticles show great promise for use in HVDC cable applications, which could reduce particle agglomeration due to its insignificant addition.