NOVELTY - A metal/ion pseudo-capacitor (MIPC) comprises multifunctional electrolyte, anode deposition substrate (ADS) (4), cathode (2), cathode current collector (1), separator function, anode current collector function, and packaging. MIPC stores electric charge by employing multifunctional electrolyte containing greater than or equal to 1 redox-active cation component which provides anode functionality through reversible metal electrodeposition and dissolution processes that occur on electrochemically active surface of ADS and is paired with cathode employing ion adsorption/desorption processes and/or faradaic processes.    USE - A metal/ion pseudo-capacitor for energy storage device (claimed).    ADVANTAGE - Energy storage device exhibits greater amount of energy stored per unit mass, per unit volume, and per unit cost than commercially available electric double layer capacitors (EDLCs) and has electrochemical capacitor (EC) behavioral characteristics of fast charge rates or rate symmetric, excellent cycle life, and potential/charge near proportionality, and anode functionality provides very large capacity compared to other methods of storing electrochemical energy.    DETAILED DESCRIPTION - A metal/ion pseudo-capacitor (MIPC) comprises multifunctional electrolyte, anode deposition substrate (ADS) (4), cathode (2), cathode current collector (1), separator function (3), anode current collector function, and packaging. MIPC stores electric charge by employing multifunctional electrolyte containing greater than or equal to 1 redox-active cation component (M) which provides anode functionality through reversible metal electrodeposition and dissolution processes that occur on electrochemically active surface of ADS and is paired with cathode employing ion adsorption/desorption processes and/or faradaic processes. Multi-functional electrolyte contains greater than or equal to 1 cation species, greater than or equal to 1 anion species, ion conduction medium, and greater than or equal to 1 phase e.g. liquid, gel, and/or solid in which the contains greater than or equal to 1 gel agent e.g. organic compound, polymer, inorganic compound, and/or silica. The composition of multifunctional electrolyte is selected from ionic liquid, salt and liquid solvent, salt and gel solvent, and/or salt and solid state ion conductor in which liquid solvent is water and/or organic liquid. INDEPENDENT CLAIMS are included for:    (1) energy storage device comprising greater than or equal to 1 MIPC cells which are combined with greater than or equal to 1 additional energy device consisting of MIPC, battery, fuel cell, and/or energy conversion device in which the combination is an electrical configuration selected from series and/or parallel; and    (2) preparation of MIPC which involves preparing ADS, preparing cathode and current collector, and combining ADS, cathode, and multifunctional electrolyte with separator and packaging materials.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional diagram of MIPC in single cathode, single ADS configuration.    Cathode current collector (1)    Cathode (2)    Optional separator film (3)    Unitary anode current collector/deposition substrate (4)