LITHIUM-ION BATTERY

A lithium-ion battery includes a positive electrode, which includes positive electrode mixture material containing positive electrode active material particles and conductive material, a negative electrode, which includes a negative electrode mixture material, and an electrolyte. The positive electrode active material particles include primary particles, a first particle aggregate of the primary particles cohered into a mass with a hollow portion having a diameter of less than 1 μm, and a second particle aggregate of the primary particles cohered into a mass with a hollow portion having a diameter of 1 μm or greater. When referring to the primary particles and the first particle aggregate as first particles, the first particles occupy 5% to 70% of the positive electrode active material particles. The positive electrode mixture material has a void percentage of 20% to 60%. The conductive material has an aspect ratio of 1:10 or greater.