According to foreign media reports, researchers from Stanford University in the United States have published a new study in Nature Energy, demonstrating how a novel battery electrolyte technology can improve the performance of lithium metal batteries.
Lithium metal batteries are lighter than lithium-ion batteries and can provide twice the energy of lithium-ion batteries with the same weight. Therefore, lithium metal batteries are a more promising battery technology for electric vehicles and other devices.
However, the growth of lithium dendrites is one of the fundamental issues affecting the safety and stability of lithium metal batteries. The growth of lithium dendrites can lead to instability at the interface between the electrode and electrolyte during the cycling process of lithium-ion batteries, continuously consuming the electrolyte and causing irreversible deposition of metallic lithium, resulting in dead lithium and low coulombic efficiency. In addition, the formation of lithium dendrites can even puncture the separator, causing internal short circuits in lithium-ion batteries, leading to thermal runaway and combustion explosions.
Researchers suggest that electrolytes are the key issue in preventing lithium dendrite growth, so we want to use organic chemistry to design and manufacture new, stable electrolytes for these batteries.
In the study, researchers added fluorine atoms to commercially available common electrolytes and utilized their ability to attract electrons to create a new molecule that enables lithium metal anodes to function well in the electrolyte. The result is a new synthetic compound, abbreviated as FDMB. Fluorine is a widely used element in lithium battery electrolytes, so FDMB can be produced in large quantities and is very cheap.
Subsequently, researchers tested this new electrolyte in lithium metal batteries. It was found that after 420 cycles of charging and discharging, the experimental battery still maintained 90% of its initial charge. Previously, ordinary lithium metal batteries could no longer be used after about 30 cycles of discharge.
In addition, researchers also measured the Coulombic efficiency (discharge efficiency) of lithium ions during the charging and discharging process, with a Coulombic efficiency of 99.52% in the case of a half cell; In the case of a full battery, the Coulombic efficiency is 99.98%.
Researchers say that this study brings hope for the application of lithium metal batteries and new prospects for the development of the next generation of electric vehicles.
