NOVELTY - An all-solid-state lithium-ion secondary cell has electrical power collector layer, positive electrode, negative-electrode active material layer, and solid electrolyte layer. The active material layer is arranged between the collector layer and solid electrolyte layer. The particle size of active material particles (102c1) of the active material layer of electrical power collector layer vicinity is smaller than the particle size of the active material particles of the active material layer of the solid electrolyte layer vicinity.    USE - All-solid-state lithium-ion secondary cell. Uses include but are not limited to mobile telephone, notebook personal computer, hybrid vehicle, electric vehicle, photovoltaic power generation applications, and wind power generation applications.    ADVANTAGE - The all-solid-state lithium-ion secondary cell has high capacity, and suppressed lithium lithium-ion conductivity in electrode thickness direction. The lithium-ion conductivity of active substance of all-solid-state lithium-ion secondary cell is high on the collector side than on the solid electrolyte side.    DETAILED DESCRIPTION - An all-solid-state lithium-ion secondary cell has an electrical power collector layer, a positive electrode, a negative-electrode active material layer, and a solid electrolyte layer. The active material layer is arranged between the collector layer and solid electrolyte layer. As for at least one of positive-electrode or negative-electrode active material layer, lithium ion conductivity (( sigma )2) of solid electrolyte layer vicinity is small with respect to lithium ion conductivity (( sigma )1) of the active material layer of the electrical power collector vicinity. The particle size of active material particles of the active material layer of electrical power collector layer vicinity is smaller than the particle size of active material particles of the active material layer of the solid electrolyte layer vicinity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of active material whose particle size is controlled in electrode thickness direction. (Drawing includes non-English language text)    Positive-electrode electrical power collector (101)    Electrical power collector side positive-electrode active material particles (102c1)    Solid electrolyte particles (104)    Electrical power collector side positive-electrode layer (107c)    Solid electrolyte side positive-electrode layer (107e)