ELECTRODE, SECONDARY BATTERY, BATTERY PACK, AND VEHICLE

According to one approach, an electrode is provided. The electrode includes an active material-containing layer which contains an active material. The active material includes a plurality of primary particles containing a niobium-titanium composite oxide. The average crystallite diameter of the plurality of primary particles is 90 nm or more. The average particle size (D50) of the plurality of primary particles is in a range of 0.1 µm to 5 µm. The average value (FU) of the roughness shape coefficient (FU) according to Formula (1) below is less than 0.70 in 100 primary particles among the plurality of primary particles. [Formula 1] FU = f f c = 4 πa ℓ 2