特許も取得“捨てられるタイヤ”が電池に　5年後に工場での量産体制目指す【佐賀県】 (25/03/20 16:28)

An unexpected ingredient. A battery has been developed using a material that would otherwise be discarded. We introduce the self-taught Miyaki Town man who developed this patented technology. When you connect a battery to a circuit and flip a switch, electricity flows and a light comes on. It's a common sight, but what's unusual about this battery is that it's a pouch-shaped battery that looks a bit like a retort meal, but it's actually made from tires that would otherwise have been discarded. [Renesas Corporation CEO Sadamitsu Yamazaki] "Battery raw materials are not sourced domestically in Japan, but overseas. About 90% of the anode material in particular comes from China. The greatest appeal of tire batteries is that they can be made from everyday items." It all came together with a simple spark of inspiration: tires and batteries, two seemingly unrelated things. Sadamitsu Yamazaki, 60, continues his research at his office in Miyaki Town. On this day, he's heating and decomposing used tires into powder, then turning them into batteries. [Renesics Co., Ltd. Representative Director Sadamitsu Yamazaki] "Negative electrode material. About 30 microns. Approximately 5 to 30 microns in size." The material is mixed with water and other ingredients using a machine to form a paste. The paste is then applied to an aluminum roll and allowed to dry and set. The roll is then cut into sheets of the size required for the battery. The sheets that represent the battery's positive and negative electrodes are alternately stacked...and then pouched together to form the battery. An electrolyte is added to this pouch in a special environment that prevents condensation, and the pouch is sealed. The battery is complete! However, from here, the battery is "grown" by repeatedly charging and discharging for about two to three weeks, and finally, the tire battery is completed. [Renesics Co., Ltd. Representative Director Sadamitsu Yamazaki] "We attach a weight, and gas will be released only the first or second time. We do this with the weight attached. This is where they grow. This is the farm, the battery farm." Yamazaki, a native of Ogi City, has studied recycling and disassembly. The impetus for developing tire batteries came 16 years ago, when he was working on a project in Gifu Prefecture to thermally decompose waste materials. Although the project was abandoned due to unprofitability, Yamazaki's interest in the waste material continued. [Renesas Corporation CEO Sadamitsu Yamazaki] "As I was removing the excess materials in the materials, especially tires, which contain a lot of sulfur, I had a sudden epiphany that maybe they could be used in a different way." Yamazaki saw potential in tires, of which approximately 1 million tons are discarded annually in Japan. Returning to Saga in 2012, he began experiments in his garage. With no prior knowledge of batteries, he taught himself, and the following year he succeeded in creating positive electrode materials from discarded tires. [Renesas Corporation CEO Sadamitsu Yamazaki] "This is a patented battery manufacturing method in 18 countries around the world." Development seemed to be going smoothly, but it took years for it to function as a battery... [Renesas Corporation CEO Sadamitsu Yamazaki] "15 years, 15 years." And so the world's first tire battery was completed. Currently, a single tire battery can discharge 1W (watt) of electricity, but Yamazaki continues to conduct experiments and research to improve its performance. Next month, he plans to conduct an experiment in which solar energy is stored in a tire battery to light street lights at night, with the goal of mass production at a factory in five years. [Renesas Corporation CEO Sadamitsu Yamazaki] "One of our themes is creating an energy-free society, and we're creating batteries that will allow homes to avoid paying electricity bills. Energy is everywhere, so we want to convert it into electricity, create batteries at a simple, low cost, and create a society where anyone can use them. That's the role we want to play in creating batteries." *The "崎" in Yamazaki's name is pronounced "tatsuzaki."