Here, we describe an electrospun mat of poly(vinyl alcohol) (PVA) and graphene oxide (GO) as a novel solid-state electrolyte matrix, which offers better performance retention upon drying after infiltrated with aqueous electrolyte. The PVA-GO mat overcomes the major issue of conventional PVA-based electrolytes, which is the ionic conductivity decay upon drying. After exposure to 45 ± 5% relative humidity at 25 °C for 1 month, its conductivity decay is limited to 38.4%, whereas that of pure PVA mat is as high as 84.0%. This mainly attributes to the hygroscopic nature of GO and the unique nanofiber structure within the mat. Monolithic supercapacitors have been derived directly on the mat via a well-developed laser scribing process. The as-prepared supercapacitor offers an areal capacitance of 9.9 mF cm-2 at 40 mV s-1 even after 1 month of aging under ambient conditions, with a high device-based volumetric energy density of 0.13 mWh cm-3 and a power density of 2.48 W cm-3, demonstrating great promises as a more stable power supply for wearable electronics.