SK On announced on the 6th that its research accomplishments aimed at enhancing the lifespan of sulfide all-solid-state batteries, conducted in collaboration with Professor Kim Dong-won’s team from Hanyang University, have been published in the April issue of the international journal in the energy and chemistry field, 'ACS Energy Letters.'
Lithium metal, which is gaining attention as a next-generation anode material for all-solid-state batteries, is becoming a key element for improving energy density and achieving high output based on a capacity approximately 10 times greater than that of existing graphite and its low electrochemical potential.
However, due to the reactive nature of lithium metal in the air, inorganic materials unevenly form on the surface, leading to reduced charging and discharging efficiency and shorter battery lifespan. When applying lithium metal anodes, the charging and discharging cycles are limited to 100 under room temperature.
To resolve this issue, SK On submerged lithium metal anodes in a special solution to remove inorganic materials and formed a protective layer based on lithium nitride (Li3N) with high conductivity and lithium oxide (Li2O) with high mechanical strength.
As a result, interfacial stability was secured, making it possible to charge and discharge more than 300 times at room temperature, effectively tripling the lifespan of existing anode metal batteries. SK On has filed domestic and international patent applications for this technology.
Furthermore, SK On, in collaboration with Professor Park Jong-hyuk’s team at Yonsei University, clarified the relationship between the gel polymer electrolyte (GPE) cure time and battery lifespan for polymer oxide composite batteries. This research was published in February in the international journal in the chemistry field, 'Angewandte Chemie.'
According to the study, the longer the thermal curing time of the gel polymer electrolyte, the more advantageous it is for maintaining battery performance. The battery using an electrolyte cured for 60 minutes showed a 9.1% decrease in discharge capacity, while one cured for only 20 minutes exhibited approximately a 34% reduction.
SK On expects that the achievements of this research will contribute to extending the lifespan of polymer oxide composite batteries. Park Ki-soo, head of SK On’s research and development division, noted, 'This achievement is the fruit of SK On's continuous research and development efforts and its technological prowess, which has blossomed through collaboration with academia,' adding, 'It will serve as a cornerstone in overcoming the technical challenges of solid-state batteries, which are gaining attention as next-generation batteries.'
SK On is currently developing two types of all-solid-state batteries, polymer oxide composite and sulfide, with the goal of commercialization in 2028 and 2030, respectively.