| abstract |
A metal ion battery includes an anode assembly and a cathode assembly ionically coupled by an electrolyte. The anode assembly includes a current collector and an anode material capable of intercalating metal ions. When the cell is not operating, ion migration between the anode and cathode is at a minimum, and the potential of the anode assembly relative to the electrolyte can increase. The increased potential can exceed the reduction potential of the current collector material, causing ions to erode from the current collector and contaminate the cathode. The use of metals, metal alloys or metal compounds lowers the electrostatic potential of the current collector and reduces erosion of the current collector. For example, in lithium-ion batteries, lithium foil in physical contact with the copper current collector lowers the overall anode potential, thereby reducing copper dissolution. |