A metal-ion battery is provided. The metal-ion battery can include a negative electrode, a positive electrode, a separator, and an electrolyte, wherein the positive electrode and the negative electrode are separated by the separator and the electrolyte is disposed between the positive electrode and the negative electrode. The negative electrode can include a negative electrode current-collector and a negative electrode active layer, wherein the negative electrode current-collector has a porous structure and the negative electrode current-collector directly contacts to the surface of the negative electrode active layer. The electrolyte can include an ionic liquid and a metal halide.