Batteries Past, Present, and Future

    As we learned over the last couple of weeks, what we see as new technology in electric generation is not that new. Guess what? The battery is even older than the means of generating electricity. We think of a battery today as a way of storing excess electrical power from things like solar panels and wind turbines, but the battery used to be the only source of electrical power. 

Photo By Ironie - Own work,
CC BY-SA 2.5, https://commons.wikimedia.org/
w/index.php?curid=2091669 Illustration of the
Baghdad Battery, earliest discovery of a battery
in history.

    The first possible batteries, the “Baghdad batteries,” were discovered during an archeological dig just outside present-day Baghdad, Iraq. They were clay jars about five-inches long, containing an iron rod encased in copper. There was evidence of acidic substances having been stored in the jars, leading Wilhelm Konig, who discovered the jars, to believe they were batteries. Since the discovery, replicas have been made and have proven to generate electricity. These batteries were dated from around 200 B.C. We do not really know what they were used for, but other discoveries indicate that they may have been used for electroplating. Electroplating is a method of using electrical current to coat one type of metal with another.
    What I find surprising is that batteries did not reappear on the scene of history until 1799, around 2000 years after these first batteries would have been created. Alessandro Volta created the first battery, not including these ancient ones in 1799, by stacking layers of zinc, cloth, and silver in a brine solution. This was not the first chemical device to generate electricity, but it was the first to emit steady, lasting currents. Volta’s voltaic pile had limitations, because as it grew larger, the weight of the plates squeezed the brine out of the cloth causing the battery to fail. The discs also corroded quickly, causing a short-lived battery. Despite these shortcomings, the standard unit of electric potential is called the volt in his honor. Volta’s battery made many new experiments possible, including the first electrolysis of water by Anthony Carlisle. Carlisle used Volta’s battery to separate water into hydrogen and oxygen for the first time.

Photo By I, GuidoB, CC BY-SA 3.0,
 https://commons.wikimedia.org/w/
index.php?curid=2249821
A voltaic pile, the first chemical battery.

    The next major improvement to the battery came from John Fredric Daniell in the form of the Daniell Cell in 1837. He found a way to solve the biggest issue with Volta’s battery, which was the build-up of hydrogen bubbles on the copper plates. He solved this by utilizing a copper sulfate solution separated from a zinc bar, submerged in sulfuric acid by an earthenware barrier. The barrier kept the liquids from mixing, but allowed the chemical ionization to occur, and without the copper plate coming in direct contact with the acid, the hydrogen bubbles did not build up on the plate. This gave his battery a much longer life expectancy.
    In 1860, a Frenchman named Callaud invented the gravity cell, which was a simplified Daniell Cell in which he eliminated the earthware barrier, reducing the internal resistance of the system and increasing the current yielded by the battery. His battery was the battery of choice for the American and British telegraph networks and was used until the early 1950s.
    Our most recent batteries are still based on the concept of chemical reactions between metals when accelerated by acid compounds, creating an electrical current. We have learned a lot about how the process works, and our greater knowledge of chemical processes have allowed us to create better, longer lasting batteries. The three most common types of batteries today are nickel-metal hydride non-rechargeable, lithium-ion and lead-acid rechargeable batteries. 
    This leads me to ask, what is the battery of the future? Batteries are the largest limiting factor in modern technology, from robotics, computers and cellphones to electric cars. We have been searching for decades for a more efficient, smaller, lighter battery that stores or produces larger amounts of power. The most efficient batteries to date are lithium polymer batteries that were released by Sony in 1997. These batteries hold their electrolytes in a solid form instead of a liquid, making it possible to form them in different sizes and shapes. 
    For now we can only speculate that newer chemical compounds and manufacturing techniques will make smaller, lighter and safer batteries in the future. If you are interested in battery technology, a great documentary on the topic was released in 2017 by PBS and is available on DVD. The files is titled “Search for the Super Battery: Discover the Powerful World of Batteries.”