Science_afficionado writes: A team of engineers and materials scientists at Vanderbilt University have discovered how to make high-performance batteries using scraps of metal from the junkyard and common household chemicals. The researchers believe their innovation could provide the large amounts of economical electrical storage required by the grid to handle alternative energy sources and may ultimately allow homeowners to build their own batteries and disconnect entirely from the grid. Vanderbilt University News reports: "To make such a future possible, Pint headed a research team that used scraps of steel and brass -- two of the most commonly discarded materials -- to create the world's first steel-brass battery that can store energy at levels comparable to lead-acid batteries while charging and discharging at rates comparable to ultra-fast charging supercapacitors. The research team, which consists of graduates and undergraduates in Vanderbilt's interdisciplinary materials science program and department of mechanical engineering, describe this achievement in a paper titled 'From the Junkyard to the Power Grid: Ambient Processing of Scrap Metals into Nanostructured Electrodes for Ultrafast Rechargeable Batteries' published online this week in the journal ACS Energy Letters. The secret to unlocking this performance is anodization, a common chemical treatment used to give aluminum a durable and decorative finish. When scraps of steel and brass are anodized using a common household chemical and residential electrical current, the researchers found that the metal surfaces are restructured into nanometer-sized networks of metal oxide that can store and release energy when reacting with a water-based liquid electrolyte. The team determined that these nanometer domains explain the fast charging behavior that they observed, as well as the battery's exceptional stability. They tested it for 5,000 consecutive charging cycles -- the equivalent of over 13 years of daily charging and discharging -- and found that it retained more than 90 percent of its capacity."