According to foreign media reports, researchers at Hanyang University in Seoul, South Korea, have developed a lithium metal battery (LMB), specifically Li / NCM battery. They said the battery was designed to meet the operational requirements of electric vehicles and was superior to lithium metal batteries mentioned in previous literature. The new LMB supports fast charging while providing high energy density.
Lithium metal with a theoretical capacity of 3860 mahg-1 is an ideal anode material for high energy density energy storage batteries. However, when applied to electric vehicles, LMB needs to adapt to the actual operating conditions. If the battery is charged rapidly, the growth of harmful lithium dendrites will be accelerated and the parasitic reaction between lithium metal anode and electrolyte will be intensified. Under the condition of fast charging and high active material loading, the growth of lithium dendrite leads to the decrease of cycle efficiency, which hinders the use of LMB in electric vehicles.
Hanyang research team used modified organic electrolyte and pretreated lithium metal to form a solid electrolyte interface layer on the surface of lithium anode. After the lithium metal anode was pretreated with lino 3, a layer of SEI film rich in Li2O will be formed on the surface of the anode, which can provide necessary mechanical strength and prevent the SEI layer from being broken down prematurely.
Combined with Al doped full concentration gradient Li [ni0.75co0.10mn0.15] O2 cathode, the researchers constructed an LMB with an area capacity of 4.1mahcm-2, which can stably cycle for more than 300 times under the high current density of 3.6macm-2, which is unprecedented. After 500 cycles in the bag cell, the LMB can maintain 90% of its initial capacity. "We believe that this study is an important step in the design mileage of LMB and can effectively stabilize the lithium metal surface," the researchers said. In addition, the importance of choosing the best cathode material in the practical application of LMB is proposed.
