ELECTRODE, SECONDARY BATTERY, BATTERY PACK, AND VEHICLE

According to one embodiment, an electrode is provided. The electrode includes a current collector, a first layer formed on the current collector, and a second layer formed on at least part of the first layer. The first layer contains a monoclinic niobium titanium composite oxide. The second layer contains lithium titanate having a spinel structure. A porosity P of the second layer is within a range from 30% to 80%.