Revolutionary Coating Technology Increases Battery Capacity Retention by Sevenfold and Triples Runtime

Breakthrough Tech Boosts Battery Capacity Retention by 7 Times; Triples Runtime
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Batteries equipped with MoS2-coated current collectors have demonstrated stable operation for over 300 hours. Researchers in South Korea have developed a cost-effective two-dimensional material that extends the lifespan of next-generation anode-free all-solid-state batteries (AFASSBs) by a remarkable seven times. The research team, led by Dr. Ki-Seok An and Dr. Dong-Bum Seo from the Korea Research Institute of Chemical Technology (KRICT), created a molybdenum disulfide (MoS2) thin film coating that significantly enhances battery stability and capacity retention.

This MoS2 thin film, grown through metal-organic chemical vapor deposition (MOCVD) onto stainless steel (SUS) current collectors, acts as a sacrificial layer that interacts with lithium during cycling. The innovative material, designed in collaboration with Dr. Sangbaek Park from Chungnam National University, has the potential to pave the way for more durable, compact, and safer batteries that completely eliminate the conventional anode.

### A Revolutionary Technology

Unlike conventional lithium-ion batteries that utilize liquid electrolytes, which pose safety risks due to lithium dendrite growth during charging, solid-state batteries (SSBs) offer enhanced safety, improved energy density, and more stable performance in low-temperature environments. Anode-free solid-state batteries (AFASSBs), considered the next significant advancement in battery technology, eliminate the anode during production. During the initial charge, lithium ions migrate from the cathode and directly plate onto the current collector, forming a lithium layer. This design reduces the cell volume while increasing energy density.

However, this increased performance comes with challenges. Repeated lithium plating and stripping at the solid electrolyte (SE) and current collector (CC) interface can lead to interfacial instability, causing uneven lithium deposition, dendrite formation, and reduced cycle life. Although noble metal coatings, such as silver (Ag) and indium (In), have been employed to stabilize the SE–CC interface, their high costs and complex processing have hindered widespread commercialization.

### Nearing Real-World Debut

To address these challenges, the research team turned to MoS2, a well-studied two-dimensional material known for its applications in semiconductors and energy systems. By using metal-organic chemical vapor deposition, they applied low-cost MoS2 nanosheet thin films onto stainless steel current collectors, providing a scalable and more affordable alternative to traditional noble metal coatings.

During battery cycling, MoS2 undergoes a conversion reaction with lithium, forming molybdenum metal and lithium sulfide (Li2S). This dynamic interfacial layer serves as a buffer zone, enhancing lithium affinity and preventing the formation of dangerous dendrites. As a result, batteries with MoS2-coated current collectors exhibit significantly longer lifespans and improved performance compared to their uncoated counterparts.

Laboratory tests revealed that cells with MoS2-coated current collectors maintained stable operation for over 300 hours—over three times longer than those using bare stainless steel, which short-circuited after approximately 95 hours. Full-cell prototypes also showed promising results, with a 1.18-fold increase in initial discharge capacity (from 136.1 to 161.1 mAh/g) and a sevenfold improvement in capacity retention, rising from 8.3% to 58.9% after 20 cycles.

Dr. Young-Kuk Lee, president of KRICT, expressed optimism about the technology’s future, stating, “Though still in its early stages, we expect this core next-generation technology to be ready for practical use by 2032. It could accelerate the commercialization of all-solid-state batteries across various applications.” The findings of this study have been published in the journal *Nano-Micro Letters*.