Abstract: Systems, methods, and apparatus configured for the osmotic injection of water in electrochemical systems are generally described. In certain embodiments, water can be transported from a water-containing liquid in an environment outside the electrochemical cell into the electrochemical cell across an osmotic medium fluidically separating an interior compartment of the electrochemical cell from the environment outside the electrochemical cell. The systems, methods, and apparatus described herein can be, according to certain embodiments, configured to be part of an electrochemical system in which water is consumed (e.g., as a reactant).

Abstract: Systems, methods, and apparatus configured for the mitigation of hydrogen accumulation within electrochemical systems are generally described. The systems, methods, and apparatus described herein can be, according to certain embodiments, configured to be part of an electrochemical system in which hydrogen is generated (e.g., as a reaction byproduct).

Abstract: 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)4?) 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.

Abstract: 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.

Abstract: An anaerobic aluminum-water electrochemical cell that includes: a plurality of electrode stacks, each electrode stack comprising an aluminum or aluminum alloy anode, and at least one solid cathode configured to be electrically coupled to the anode; a liquid electrolyte between the anode and the at least one cathode; 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, configured to introduce water into the housing. The electrolyte includes a hydroxide base at a concentration of at least 0.05 M to at most 3 M.

Abstract: An anaerobic aluminum-water electrochemical cell includes electrode stacks, each electrode stack having an aluminum or aluminum alloy anode, and at least one solid cathode configured to be electrically coupled to the anode. The cell further includes a liquid electrolyte between the anode and the at least one cathode, 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, configured to introduce water into the housing.

Abstract: 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.

Abstract: An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack including an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing, and an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.5% to at most 13% of the saturation concentration when water is introduced between the anode and the least one cathode. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

Abstract: An anaerobic aluminum-water electrochemical cell that includes: a plurality of electrode stacks, each electrode stack featuring an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing. The electrochemical cell also includes an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.05 M to at most 3 M when water is introduced between the anode and at least one cathode of the electrochemical cell. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

Abstract: 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.

Abstract: An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack featuring an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing; and an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.5% to at most 13% of the saturation concentration when water is introduced between the anode and the least one cathode.

Abstract: An electrochemical cell is provided. The cell includes: a plurality of electrode stacks, each electrode stack including an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

Abstract: Waste management in electrochemical systems, such as electrochemical systems in which an electrochemically active material comprising aluminum is employed, is generally described.

Abstract: 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.

Abstract: 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)4?) 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.

Abstract: 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.

Abstract: 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.

Abstract: An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: a plurality of electrode stacks, each electrode stack featuring an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing; and an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.5% to at most 13% of the saturation concentration when water is introduced between the anode and the least one cathode.

Abstract: An anaerobic aluminum-water electrochemical cell that includes: a plurality of electrode stacks, each electrode stack featuring an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing. The electrochemical cell also includes an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.05 M to at most 3 M when water is introduced between the anode and at least one cathode of the electrochemical cell. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

Abstract: An electrochemical cell is provided. The cell includes: a plurality of electrode stacks, each electrode stack including an aluminum or aluminum alloy anode, 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, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.