Scientists have developed a new electrolyte that dramatically improves the perfo
Back
2020/10/27 09:41:51
On June 22, researchers at Stanford University published a new study in The journal Nature Energy, showing how a new battery electrolyte technology can improve the performance of lithium-metal batteries.
Lithium-metal batteries are lighter than lithium-ion batteries and can deliver twice the energy of lithium ions at the same weight.Lithium-metal batteries are therefore a more promising battery technology for electric cars and other devices.
However, the growth of lithium dendrite is one of the fundamental problems affecting the safety and stability of lithium metal batteries.The growth of lithium dendrites will lead to the instability of the interface between electrodes and electrolyte in the cycling process of lithium ion batteries, which will continuously consume the electrolyte and lead to the irreversible deposition of lithium metal, forming dead lithium and resulting in low Coulombic efficiency.In addition, the formation of lithium dendrites can even puncture the diaphragm and cause the short connection inside the lithium ion battery, causing the thermal control of the battery to cause combustion explosion.
The electrolyte is a key problem in preventing the growth of lithium dendrites, so we wanted to use organic chemistry to design and produce new, stable electrolytes for these batteries, the researchers said.
In the study, the researchers added fluorine atoms to a commercially available electrolyte and used its ability to attract electrons to create a new molecule that makes the lithium metal anode work well in the electrolyte.The result is a new synthetic compound, called FDMB.Fluorine is a widely used element in lithium battery electrolytes, so FDMB can be made in large quantities and is very cheap.
The researchers then tested the new electrolyte in lithium-metal batteries.It found that after 420 charge and discharge cycles, the battery remained at 90% of its initial charge.Previously, ordinary lithium-metal batteries failed after about 30 cycles.
In addition, the researchers measured the coulomb efficiency (DISCHARGE efficiency) of lithium ions during charging and discharging, which was 99.52 percent in the case of semi-batteries.The coulomb efficiency is 99.98% in the full battery condition.
The researchers say the research offers hope for the use of lithium-metal batteries and for the development of the next generation of electric cars.
Previous
