ACTIVE MATERIAL, ELECTRODE, SECONDARY BATTERY, BATTERY PACK, AND VEHICLE

According to one embodiment, an active material is provided. The active material includes a primary particle including an NbTiOphase and at least one Nb-rich phase selected from an NbTiOphase and an NbTiOphase. In the primary particle, a ratio M/Mof substance amount of niobium to titanium satisfies 5.0