Provided a method for generating an electrical current. The method includes: introducing water between the anode and at least one cathode of an electrochemical cell, to form an electrolyte; anaerobically oxidizing aluminum or an aluminum alloy; and electrochemically reducing water at the at least one cathode. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack comprising an anode including the aluminum or aluminum alloy, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, the electrolyte, and the physical separators; and a water injection port. When the cell is in operation, the hydroxyaluminate concentration of the electrolyte in the cell is maintained between at least 20% to at most 750% of the saturation concentration.

Provided is a method for generating an electrical current. The method includes: introducing water between the anode and at least one cathode of an electrochemical cell, to form an electrolyte; anaerobically oxidizing aluminum or an aluminum alloy; and electrochemically reducing water at the at least one cathode. When the cell is in operation, the hydroxyaluminate (Al(OH).sub.4.sup.) in the electrolyte reaches a concentration maximum and thereafter a concentration minimum. The concentration maximum is above 125% of the saturation concentration and below 2000% of the saturation concentration. The concentration minimum is below 125% of the saturation concentration and above 50% of the saturation concentration.

Provided is a method for generating an electrical current. The method includes: introducing water between the anode and at least one cathode of an electrochemical cell, to form an electrolyte; anaerobically oxidizing aluminum or an aluminum alloy; and electrochemically reducing water at the at least one cathode. When the cell is in operation, the hydroxyaluminate (Al(OH).sub.4.sup.) in the electrolyte reaches a concentration maximum and thereafter a concentration minimum. The concentration maximum is above 125% of the saturation concentration and below 2000% of the saturation concentration. The concentration minimum is below 125% of the saturation concentration and above 50% of the saturation concentration.

Provided is a method for generating an electrical current. The method includes: introducing water between the anode and at least one cathode of an electrochemical cell, to form an electrolyte; anaerobically oxidizing aluminum or an aluminum alloy at the anode; and electrochemically reducing water at the at least one cathode. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack comprising an anode including the aluminum or aluminum alloy, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, the electrolyte, and the physical separators; and a water injection port in the housing. When the cell is in operation, the concentration of aluminum species in the electrolyte is maintained between at least 0.01 M to at most 0.7 M.

Provided is a method for generating an electrical current. The method includes: introducing water between the anode and at least one cathode of an electrochemical cell, to form an electrolyte; anaerobically oxidizing aluminum or an aluminum alloy at the anode; and electrochemically reducing water at the at least one cathode. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack comprising an anode including the aluminum or aluminum alloy, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, the electrolyte, and the physical separators; and a water injection port in the housing. When the cell is in operation, the concentration of aluminum species in the electrolyte is maintained between at least 0.01 M to at most 0.7 M.

An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack comprising an aluminum or aluminum alloy anode, and at least one cathode configured to be electrically coupled to the anode and having a surface characterized by an electrochemical roughness factor of at least 5 and a mean pore diameter of at least 50 m; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, an electrolyte, and the physical separators; and a water injection port, in the housing, configured to introduce water into the housing.

An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack comprising an aluminum or aluminum alloy anode, and at least one cathode configured to be electrically coupled to the anode and having a surface characterized by an electrochemical roughness factor of at least 5 and a mean pore diameter of at least 50 m; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, an electrolyte, and the physical separators; and a water injection port, in the housing, configured to introduce water into the housing.

Provided herein are energy storage devices comprising a first electrode comprising a layered double hydroxide, a conductive scaffold, and a first current collector; a second electrode comprising a hydroxide and a second current collector; a separator; and an electrolyte. In some embodiments, the specific combination of device chemistry, active materials, and electrolytes described herein form storage devices that operate at high voltage and exhibit the capacity of a battery and the power performance of supercapacitors in one device.

The invention relates to a reversible electrochemical system intended to operate alternately in electrolysis cell mode and in fuel cell mode, comprising: a primary device of which: the primary anode (13) is suitable for carrying out an oxidation of the water (OER) originating from a first anode port and an oxidation of the hydrogen (HOR) originating from a second anode port, and the primary cathode (15) is suitable for carrying out a reduction of protons (HER), and a reduction of oxygen (ORR) originating from a second cathode port; a secondary device of which: the secondary anode (23) is suitable for carrying out an oxidation of hydrogen (HOR) originating from the primary anode and an oxidation of hydrogen (HOR) originating from the second anode port; the secondary cathode (25) is suitable for carrying out a reduction of protons (HER) and a reduction of oxygen (ORR) originating from the second cathode port.

The invention relates to a reversible electrochemical system intended to operate alternately in electrolysis cell mode and in fuel cell mode, comprising: a primary device of which: the primary anode (13) is suitable for carrying out an oxidation of the water (OER) originating from a first anode port and an oxidation of the hydrogen (HOR) originating from a second anode port, and the primary cathode (15) is suitable for carrying out a reduction of protons (HER), and a reduction of oxygen (ORR) originating from a second cathode port; a secondary device of which: the secondary anode (23) is suitable for carrying out an oxidation of hydrogen (HOR) originating from the primary anode and an oxidation of hydrogen (HOR) originating from the second anode port; the secondary cathode (25) is suitable for carrying out a reduction of protons (HER) and a reduction of oxygen (ORR) originating from the second cathode port.