Electrode, electrode group, secondary battery, battery pack, and vehicle

An electrode group comprising:

• a positive electrode;
• and
• a negative electrode,
• the electrode group having a wound structure of a flat shape where a stack comprising the positive electrode and the negative electrode is wound in a manner where a center of the wound structure lies along a first direction,
• wherein the negative electrode comprises:
• a current collector;
• and
• an active material-containing layer in contact with the current collector, the active material-containing layer comprising a carbon nanotube and titanium-containing oxide particles having an average particle size of 0.1 μm to 3 μm,
• a peel strength between the current collector and the active material-containing layer according to a surface/interface cutting method is from 0.2 kN/m to 0.7 kN/m, and
• a part of the active material-containing layer of the negative electrode is in an unbound state with respect to the current collector at an innermost bent section positioned innermost in the wound structure, the unbound state being a state where an interspace is present between the current collector and the active material-containing layer or where the current collector and the active material-containing layer are in contact with each other but not bound to each other.