Electrolyte and power storage device

A technique that can improve ionic conductivity is provided. An electrolyte includes an inorganic composite particle that is a composite of an inorganic particle with a compound having a betaine structure and one or more functional groups selected from a (meth)acryloxy group, a Si(OR)group (R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), and an Al(OR)group (R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms).