This disclosure relates to an electrolyte for an aluminum electrolytic capacitor. An electrolyte according to one embodiment includes a protic fluid and a high dielectric co-solvent or a dipolar aprotic. According to various embodiments, the electrolyte is pH buffered to less than approximately 6.8 pH. The protic fluid includes ethylene glycol and the high dielectric co-solvent includes N-methylformamide, in various embodiments. The disclosure further relates to methods for manufacturing an electrolyte, and capacitors and implantable devices including a supporting electrolyte selected for optimal cation size and charge and anion solubility.