To develop alternatives to lithium-based batteries and reduce dependence on rare metals, researchers at Georgia Institute of Technology have developed a promising new cathode and electrolyte system that replaces expensive with low-cost transition metal fluorides and solid polymer electrolytes. Metals and traditional liquid electrolytes.
The new cathode is made of ferrofluoride active materials and solid polymer (a plastic) electrolyte nanocomposite. To make this cathode, researchers developed a method of infiltrating a solid polymer electrolyte into a pre-made iron fluoride electrode, and then hot-pressing the entire structure to increase density and reduce voids. Polymer-based electrolytes have two outstanding advantages. One is that they have the ability to bend and adapt to the swelling of ferric fluoride during cycling. The other is that they can form a very stable flexible interface with ferric fluoride. Key issues such as the swelling of iron and the large number of side reactions.
Researchers tested several variants of the new solid-state battery to analyze its performance over 300 charge and discharge cycles at a high temperature of 50 ° C. It was found that the key to enhancing battery performance is the solid polymer electrolyte. When used with solid polymer electrolytes, metal fluorides show extraordinary stability even at high temperatures. This is expected to lead to safer, lighter and cheaper lithium-ion batteries. In addition, the lithium capacity of iron fluoride is more than double that of conventional cobalt-based or nickel-based cathodes. And iron is 300 times cheaper than cobalt and 150 times cheaper than nickel.
In the future, researchers will continue to improve and develop new solid electrolytes for fast charging, and incorporate solid and liquid electrolytes in the new design to be fully compatible with traditional battery manufacturing technologies used in large battery factories.
Whether it is a pure electric vehicle or a renewable energy battery, rare metals are essential materials. This has led to increasing competition for raw materials such as cobalt and nickel, and even securing rare metals has become a national issue. That's why scientists set out to find alternatives to ease dependence. The new research has shown great potential now, but in the next step, researchers must make the new battery the same capacity as the lithium battery used as the electrode of the rare metal in the past, and the attenuation also meets the requirements, in order to really consider commercial production.