Provided are an electrode for a lithium-ion secondary battery enabling the realization of a battery that has a high volume energy density and exhibits a low level of degradation in output due to repeated charging and discharging even in a case in which the amount of an electrolyte solution held by the electrode is low, and a lithium-ion secondary battery including the positive electrode.
The coexistence of a high dielectric oxide solid and a highly concentrated electrolyte solution in a gap between articles of an active material inside the electrode is achieved.