Carbon nanotube/graphene oxide‐added CaO‐B2O3‐SiO2 glass/Al2O3 composite as substrate for chip‐type supercapacitor

A CaO-B2O3-SiO2 (CBS) glass/40wt% Al2O3 composite sintered at 900 degrees C exhibited a dense microstructure with a low porosity of 0.21%. This composite contained Al2O3 and anorthite phases, but pure glass sintered at 900 degrees C has small quantities of wollastonite and diopside phases. This composite was measured to have a high bending strength of 323MPa and thermal conductivity of 3.75W/(mK). The thermal conductivity increased when the composite was annealed at 850 degrees C after sintering at 900 degrees C, because of the increase in the amount of the anorthite phase. 0.25wt% graphene oxide and 0.75wt% multi-wall carbon nanotubes were added to the CBS/40wt% Al2O3 composite to further enhance the thermal conductivity and bending strength. The specimen sintered at 900 degrees C and subsequently annealed at 850 degrees C exhibited a large bending strength of 420MPa and thermal conductivity of 5.51W/(mK), indicating that it would be a highly effective substrate for a chip-type supercapacitor.