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.