Energy Density and Duration Improved
The Korea Advanced Institute of Science and Technology (KAIST) announced on Jan. 19 that its research team led by professor Lee Jin-woo has developed an energy density- and duration-improved lithium-sulfur battery together with a POSTECH research team of professor Han Jung-woo and LG Energy Solution.
The energy density of a lithium-sulfur battery is expected to be 200 percent to 300 percent of that of a commercial lithium-ion battery. As such, global attention is focusing on lithium-sulfur batteries as one type of next-generation rechargeable batteries.
In order to make a high-energy density lithium-sulfur battery, it is essential to reduce electrolyte use in it while ensuring a high capacity and a high drive voltage. However, electrolyte reduction in it results in an increase in electrolyte contamination attributable to lithium polysulfide dissolution, which adversely affects lithium-ion conductivity and electrochemical conversion reaction activity to limit increases in capacity and drive voltage.
The researchers developed a Fe atom-based cathode material capable of considerably reducing the dissolution and improving the activity. With the functional material that has an optimized electron configuration, the dissolution can be inhibited efficiently, lithium polysulfide can be converted into insoluble lithium sulfide with greater ease, and reversible capacity, drive voltage and duration stability improvements can be achieved even with a small amount of electrolyte.
“The new cathode material can provide a 30 percent improvement in energy density from existing commercial lithium-ion batteries, that is, at least 320 Wh kg-1 in an Ah-level lithium-sulfur pouch cell,” they said. Details of the research are available on the official website of the Advanced Materials journal.