Lithium-ion battery including doped positive electrode active material

A lithium-ion battery includes a positive electrode and an electrolyte. A positive electrode active material included in the positive electrode includes a doping element. The doping element includes at least one selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, and a percentage of the doping element satisfies 0.01%≤W1%≤0.5%. The electrolyte includes an oligomer according to formula (I), and a percentage of the oligomer satisfies 0.1%≤W2≤10% s.