NOVELTY - The cell has a porous anode current collector with surface areas to capture and store ions of first metal without using a separate anode active material. The anode current collector includes a specific surface area greater than 100 square meter per gram, and is in direct contact with an electrolyte. A porous separator is placed between the anode current collector and a cathode current collector. An ion source of the first metal is placed in the anode current collector or a cathode current collector, and obtains an open circuit voltage (OCV) from 0.1 V to 4.5 V when the cell is made.    USE - Rechargeable dual-electroplating cell e.g. lithium-ion cell and magnesium-ion cell, for use in an electric vehicle (EV), power tool, and consumer electronic device.    ADVANTAGE - The cell exhibits cell-level specific energy typically greater than 500 watts per kilogram, so that the cell can deliver high energy density and high power density. The cell includes a high-capacity cathode active material that can be readily prepared without performing through an energy-intensive sintering process. The cathode current collector includes weight and volume lower than combined weight and volume of separate and discrete cathode electrode and cathode current collector and stores magnesium or lithium atoms on massive surfaces of the cell without the need to undergo intercalation or solid-state diffusion, thus achieving significantly improved power density and reduced recharge times of the cell. The cathode current collector is electrically and thermally conductive for enabling high-rate capability and effective heat dissipation in the cell, and contains little or no oxygen, for reducing or eliminating potential for fire hazard or explosion.    DETAILED DESCRIPTION - The ion source comprises chip, foil, powder, particle, fiber, rod, wire, film, and coating. The electrolyte is one of organic liquid electrolyte, ionic liquid electrolyte, gel electrolyte, polymer electrolyte, and solid electrolyte. The cathode current collector or anode current collector is selected from a porous sheet, paper, web, film, fabric, non-woven, mat, aggregate, or foam of carbon or graphite material selected from graphene, graphene oxide, reduced graphene oxide, graphene fluoride, doped graphene, functionalized graphene, expanded graphite, exfoliated graphite or graphite worms, chemically etched or expanded soft carbon, chemically etched or expanded hard carbon, exfoliated activated carbon, chemically etched or expanded carbon black, chemically etched multi-walled carbon nanotube, nitrogen-doped carbon nanotube with enhanced metal ion capturing ability, boron-doped carbon nanotube with an enhanced metal ion capturing ability, chemically doped carbon nanotube with an enhanced metal ion capturing ability, ion-implanted carbon nanotube with an enhanced metal ion capturing ability, chemically treated multi-walled carbon nanotube with an inter-graphene planar separation greater than 0.4 nm, chemically expanded carbon nano-fiber, chemically activated carbon nano-tube, chemically treated carbon fiber, chemically activated graphite fiber and chemically activated carbonized polymer fiber. An INDEPENDENT CLAIM is also included for a method for operating a dual-electroplating cell.    DESCRIPTION OF DRAWING(S) - The drawing shows schematic views of porous current collectors used in a dual-electroplating cell.