Researchers in Korea have developed a large-capacity anode material for sodium ion batteries using sodium, which is much cheaper than lithium. Sodium ion batteries are attracting attention as a next-generation battery candidate to replace lithium-ion batteries that are currently commercially available and widely used.
The Korea Institute of Science and Technology (KIST) announced on the 18th that Dr. Sang-ok Kim's team of the Energy Storage Research Group developed a negative electrode material with improved performance and low cost that can be applied to sodium-ion batteries, which are cheaper than lithium-ion batteries.
As electric vehicles, as well as various mobile devices, are rapidly commercialized, the demand for secondary batteries is rapidly increasing.
However, lithium-ion batteries that use expensive lithium are actively researching around the world to develop high-efficiency, high-efficiency secondary batteries that are expensive enough to account for about 30% of the cost of electric vehicles.
One of the candidates for next-generation secondary batteries to replace lithium-ion batteries is sodium-ion batteries, which use sodium, which has more than 500 times more crust storage than lithium. When commercialized, sodium ion batteries are expected to be 40% cheaper than lithium ion batteries.
The research team uses molybdenum disulfide (MoS₂), a metal sulfide material that is attracting attention as a large-capacity anode material candidate in this study, to store 1.5 times more electricity than the graphite anode material of lithium-ion batteries, and even if charging and discharging are repeated 200 times, the performance decreases. Developed a stable cathode material that does not.
A simple process of making molybdenum disulfide nanoparticles and then heat-treating them with silicone oil, which is an inexpensive eco-friendly material, is a problem of structural instability that occurs during operation with high electrical resistance and high electrical resistance. Overcame.
The material developed by the research team has an electrical storage capacity of 600㎃h/g or more, which is more than twice as large as a molybdenum disulfide material without a coating layer, and the stability that the storage capacity remains intact even after 200 times of rapid charging and discharging within 5 minutes. Showed.
This is because the ceramic nanocoating layer, which has high conductivity and rigidity on the surface of molybdenum disulfide material, lowers the resistance of the material, stabilizes the structure, and can store additional electricity on the surface of the coating layer, the research team explained.
The research team added that for the practical use of this technology, follow-up studies such as large electrode area and full-cell compatibility studies with anode materials are needed.
Dr. Kim Sang-ok said, through this technology that uses inexpensive and eco-friendly materials, we expect to accelerate the commercialization of sodium-ion batteries for large-capacity power storage devices by lowering the cost of the electrode material production process.
The research results were published in the latest issue of the international academic journal ACS Nano.