Editing Energy storage (section)

===== Aluminum =====
[[Aluminum]] has been proposed as an energy store by a number of researchers. Its [[electrochemical equivalent]] (8.04 Ah/cm3) is nearly four times greater than that of lithium (2.06 Ah/cm3).<ref name="Aluminum-density" /> Energy can be extracted from aluminum by reacting it with water to generate [[hydrogen]].<ref name="Alchemy white paper" /> However, it must first be stripped of its natural [[oxide]] layer, a process which requires pulverization,<ref name="Army" /> chemical reactions with caustic substances, or alloys.<ref name="Woodall" /> The byproduct of the reaction to create hydrogen is [[aluminum oxide]], which can be recycled into aluminum with the [[Hall–Héroult process]], making the reaction theoretically renewable.<ref name="Woodall" /> If the Hall-Heroult Process is run using solar or wind power, aluminum could be used to store the energy produced at higher efficiency than direct solar electrolysis.<ref name="Aluminum Solar Storage" />