Provided is a bi-polar electrode for a battery, the electrode comprising: (a) a current collector comprising a conductive material foil (e.g. metal foil) having a thickness from 10 nm to 100 μm and two opposed, parallel primary surfaces, wherein one or both of the primary surfaces is coated with a layer of exfoliated graphite or expanded graphite material having a thickness from 10 nm to 50 μm; and (b) a negative electrode layer and a positive electrode layer respectively disposed on the two sides of the current collector, each in physical contact with the layer of exfoliated graphite or expanded graphite material or directly with a primary surface of the conductive material foil (if not coated with a exfoliated or expanded graphite layer). Also provided is a battery comprising multiple (e.g. 2-300) bipolar electrodes internally connected in series. There can be multiple bi-polar electrodes that are connected in parallel.