The battery "coming out" 120 years in advance

             An electric car flies past a pedestrian on a gravel road in West Orange, New Jersey. The spacious interior of the car obviously surprised some people. Its speed was twice that of the traditional models at that time, and the dust raised so high that the horses on the street could not help wrinkling their noses.

            The above scene happened in the early 20th century, and the owner of this car is Thomas Edison. Although electric cars were nothing new at the time, most of them relied on heavy, clumsy lead-acid batteries. Edison installed a new type of battery in his car and hoped that it would soon be able to power vehicles all over the United States. This new battery belongs to nickel iron battery. It was first patented by Swedish inventor Ernest waldmar youngner in 1899. Later, it was improved by Edison and used in cars.
           Edison said the battery was extremely durable and charged twice as fast as a lead-acid battery. He even reached an agreement with Ford to produce what he calls a more efficient electric car.

But ferronickel batteries do have some problems. It was larger and more expensive than lead-acid batteries, which were more widely used at the time. And it releases hydrogen when it's charging, which is troublesome and dangerous.

          Unfortunately, by the time Edison improved his prototype design, electric vehicles had gradually been replaced by fossil fuel vehicles with longer driving range. Edison's agreement with Ford also ran aground. But his battery was later used in other areas, such as railway signal lights. In these places, the huge size of the battery is not a problem.
          But more than a century later, engineers will find that there is a huge potential hidden in ferronickel batteries. Now, people are studying it, hoping it can solve the problem of unstable and intermittent supply of renewable energy such as wind and solar energy. In addition, its by-product hydrogen, once a headache, now seems to be one of the biggest uses of the battery.

         Around 2015, a research team at Delft University of technology in the Netherlands accidentally found a way to use the nickel iron battery based on the hydrogen generated by the battery. In the process of battery charging, when the current passes through the battery, it will undergo a chemical reaction to generate hydrogen and oxygen. The team believes that the reaction is similar to the reaction of water to hydrogen, that is, the electrolysis of water.
        "In my opinion, the chemical principles are the same." The team leader, Falco Mulder, pointed out. The decomposition reaction of water is a way to produce hydrogen fuel, and as long as the energy driving the reaction is also produced by renewable energy, hydrogen is a 100% clean energy.

          Mulder and his team were also surprised to find that when the electrode of the nickel iron battery began to decompose water, the energy stored in the electrode became even higher than before hydrogen was generated. In other words, when nickel iron battery is used as electrolysis device at the same time, it becomes a better battery. They were also surprised to find that the electrode of the battery can withstand the electrolytic reaction well, while in traditional batteries, the electrolytic reaction often causes serious battery loss. "In addition, we are very satisfied with the energy efficiency of the battery in the above process, which can reach 80% - 90%." Mulder pointed out.
         Mulder called their work "battery electrolyser" and hoped that the discovery would help solve the two major challenges of renewable energy: the ability to store energy and the ability to produce clean energy when the battery is full.

        "We often hear all kinds of discussions about batteries and hydrogen," Mulder points out. "There's always been some kind of competition between these two directions, but we need both."