SK On discovers method to enhance lifespan of solid-state batteries

South Korean battery maker SK On has said that its research, conducted in collaboration with Dr. Dong-Won Kim’s group at Hanyang University in Seoul, discovered a method to improve the cycle life of sulfide-based all-solid-state lithium metal batteries (ASSLMBs). 

The study, published in ACS Energy Letters, introduces a method for forming a protective layer on the lithium metal anode surface to enhance battery safety and extend its lifespan. 

The team also filed patent applications for its key findings both domestically and internationally, according to a media release. 

To address the issue of limited lifespan of lithium, the research team removed the resistive surface layer by immersing the lithium metal anode in a specially formulated solution. This approach resulted in the formation of a protective layer featuring high ionic conductivity, attributed to lithium nitrate, and enhanced mechanical strength due to lithium oxide. 

The South Korean company said this method ensured interfacial stability, with experimental results showing that the surface-modified lithium metal anode enabled stable cycling for over 300 charge-discharge cycles at room temperature, tripling the cycle life compared to conventional lithium metal all-solid-state batteries. 

In collaboration with Dr. Jong Hyeok Park of Yonsei University, SK On announced another achievement, uncovering the relationship between battery life and the thermal curing time of gel polymer electrolytes (GPEs), the media release said. Their study was published in the journal Angewandte Chemie in February.

According to the study, longer thermal curing times for the GPEs resulted in better retention of battery performance. The study showed that batteries using electrolytes with 60 minutes of thermal curing showed a 9.1% decrease in discharge capacity, while those with just 20 minutes of thermal curing experienced a 34% decrease. 

“These achievements are the result of SK On’s continued R&D efforts and technological prowess, enabled through collaboration with academia,” said Kisoo Park, Head of R&D at SK On. “They will serve as a key foundation for overcoming the technological challenges of solid-state batteries.”