SK On Unveils Significant Enhancements to Solid-State Battery Tech

SK On has unveiled significant advancements in solid-state battery (ASSB) technology through collaborative research with leading Korean universities, aiming to enhance battery safety, longevity, and performance. 1. Enhanced Cycle Life for Sulfide-Based ASSBs In partnership with Dr. Dong-Won Kim’s team at Hanyang University, SK On developed a method to improve the lifespan of sulfide-based all-solid-state lithium metal batteries. By immersing lithium metal anodes in a specially formulated solution, a protective layer comprising lithium nitrate and lithium oxide forms, enhancing ionic conductivity and mechanical strength. This innovation tripled the battery’s cycle life, achieving over 300 charge-discharge cycles at room temperature. 2. Optimizing Gel Polymer Electrolyte (GPE) Curing Time Collaborating with Dr. Jong Hyeok Park’s group at Yonsei University, SK On investigated the impact of thermal curing time on GPEs. Findings indicate that longer curing times (60 minutes) result in better battery performance retention, with only a 9.1% decrease in discharge capacity, compared to a 34% decrease with shorter curing times (20 minutes). This research underscores the importance of curing duration in enhancing battery lifespan.

• Photonic Sintering for Hybrid Solid Electrolytes: SK On applied ultrafast photonic sintering technology, traditionally used in printed circuit board manufacturing, to create oxide-rich inorganic-organic composite hybrid solid electrolytes. This method enables low-temperature, rapid production of electrolytes with improved uniformity and cycle life.
• Advancements in LMRO Cathode Materials: In collaboration with Seoul National University, SK On explored lithium- and manganese-rich layered oxide (LMRO) cathodes for sulfide-based ASSBs. A special coating was developed to suppress oxygen release during high-temperature operations, mitigating degradation and enhancing cycle life.

SK On is progressing towards commercializing two types of ASSBs:

• Polymer-Oxide Composite ASSBs: Prototypes expected by 2027.
• Sulfide-Based ASSBs: Prototypes anticipated by 2029.

A pilot production facility is under construction at SK On’s research center in Daejeon, Korea, with completion slated for the second half of 2025.