Foreign media reported that researchers at the Argonne National Laboratory of the U.S. Department of energy (DOE) have developed a new electrolyte mixture and additive, which can make the silicon anode have higher surface stability and overall stability, thereby improving the cycle life of lithium batteries.

In order to further improve the energy density of lithium batteries, battery enterprises are actively developing new lithium battery materials. Among them, high nickel positive electrode silicon carbon negative electrode has become a new material system for battery enterprises to develop high specific energy batteries.

At present, ncm811 high nickel material has achieved large-scale application, but the commercialization of silicon carbon anode has developed slowly, mainly because the problems of easy expansion and low cycle life of silicon carbon anode have not been completely solved.

Jack vaughey, a senior chemist in the chemical science and Engineering (CSE) Department of Argonne National Laboratory, pointed out: "there are still obstacles to the commercial application of silicon anode. During the cycle, the silicon-based anode in the lithium-ion battery will react greatly with the electrolyte. With the passage of time, this process will degrade the battery and shorten the cycle life."

To solve this problem, researchers at Argonne National Laboratory developed a new electrolyte mixture and additive, which contains any of several double or triple charged metal cations (Mg2, Ca2, Zn2 or Al3). These enhanced electrolyte mixtures are collectively referred to as "mesa" (mixed salt electrolytes representing silicon anodes)

Researchers found that during the charging process, the metal cation additives in the electrolyte solution will migrate to the silicon-based anode together with lithium ions, thus forming a lithium metal silicon phase that is more stable than lithium silicon. This new battery chemistry greatly reduces the harmful side reactions between the silicon anode and the electrolyte.

Among the four metal salts tested in the battery, the added electrolyte salt with magnesium (Mg2) or calcium (Ca2) cations has proved to be the best in hundreds of charge and discharge cycles. The energy density of these batteries is 50% higher than that of graphite lithium batteries.

Baris key, a chemist in CSE department, said, "we have thoroughly tested mesa formula with complete batteries made of standard commercial related electrodes." "This new chemical is simple, scalable and fully compatible with existing battery technology."


Article source:High tech lithium power grid