Lithium-ion batteries (LIBs) have been widely used in a variety of electrochemical energy storage applications, including mobile devices, electric vehicles, and energy storage systems (ESS), and are one of the most popular types of rechargeable batteries. However, as demand has increased, its prices have also risen in the past few years. Due to its high natural reserves, low cost, and similar chemical properties to lithium, sodium ion batteries (SIBs) are expected to be a substitute for lithium ion batteries. People are becoming more and more interested in SIB batteries, but due to the lack of suitable electrode materials, the commercialization of SIB batteries is far from being realized.
According to foreign media reports, researchers at the Korea Advanced Institute of Science and Technology (KAIST) have proposed a new strategy to use copper sulfide as an electrode material to extend the cycleability of sodium ion batteries. The use of this material can promote the high-performance conversion reaction of SIB cells and is expected to achieve commercialization of SIB cells.
A team led by Professor Jong Min Yuk confirmed the use of copper sulfide to stabilize sodium storage mechanisms. Copper sulfide is an excellent electrode material. Due to its unique resistance to pulverization and transformation reaction mechanism, it has high capacity, high rate, and long cycle cycling ability, thereby promoting capacity recovery. The research results show that when using copper sulfide, the sodium ion battery is charged once a day and the service life can reach more than 5 years. In addition, copper sulfide is rich in natural materials such as copper and sulfur, which has better cost competitiveness than lithium-ion batteries. Lithium-ion batteries use lithium and cobalt.
Battery, KAIST, copper sulfide, electrode material, sodium ion battery, recyclability
Lithium-ion batteries use intercalation materials such as graphite as the negative electrode. Due to insufficient interlayer spacing, these materials cannot store large amounts of sodium. Therefore, people have begun to explore conversion and alloying reactive materials to meet the high capacity requirements of the negative electrode part. However, unlike the insertion reaction, in the transformation and alloying reactions, the volume expansion of the material is usually large, and the crystals will suddenly change, which will destroy the active material and cause serious degradation of capacity.
The research team found that in the transformation reaction, the semi-coherent phase interface and grain boundaries play a key role in achieving pulverization-resistant transformation reactions and capacity recovery. Copper sulfide generates a semi-coherent phase interface through progressive crystal change, and finally prevents the particles from pulverizing. Based on this unique mechanism, researchers have confirmed that copper sulfide has high capacity and high cycle stability regardless of size and morphology. Professor Yuk said: "Using copper sulfide can promote the development of sodium ion batteries, help develop low-cost energy storage systems, and solve the problem of dust."