Breakthrough tech boosts capacity retention in batteries by 7 times; triples runtime

Grown via metal–organic chemical vapor deposition (MOCVD), onto stainless steel (SUS) current collectors, the MoS2 thin film acts as a sacrificial layer that reacts with lithium during cycling.

The novel material, designed in collaboration with Sangbaek Park, PhD, a professor at Chungnam National University, and his team, could potentially pave the way for more durable, compact, and safer batteries that eliminate the conventional anode altogether.

A revolutionary technology

While conventional lithium-ion batteries rely on liquid electrolytes, they are prone to safety risks, especially those associated with lithium dendrite growth during charging.

Dendrites, which are needle-like structures form due to uneven lithium deposition on the anode surface, can puncture the separator, potentially leading to short circuits or even thermal runaway.

In contrast, solid-state batteries (SSBs) replace flammable liquid electrolytes with solid-state electrolytes (SEs), offering enhanced safety, greater energy density, and more stable performance, particularly in low-temperature environments.

Meanwhile, anode-free solid-state batteries (AFASSB) are widely regarded as the next major leap in battery technology, as they eliminate the anode during fabrication. During the initial charge, lithium ions migrate from the cathode and plate directly onto the current collector, forming a lithium layer. This design significantly reduces cell volume while enhancing energy density.

But that boost in performance comes at a cost, as repeated lithium plating and stripping at the solid electrolyte (SE)-current collector (CC) interface often leads to interfacial instability, resulting in uneven lithium deposition, dendrite formation, and reduced cycle life.

Although noble metal coatings such as silver (Ag) and indium (In) have been used to stabilize the SE–CC interface, their high cost and complex processing continue to hinder commercialization.

Nearing real-world debut

Now, in a bid to overcome the challenge, the team turned to MoS2, a widely studied two-dimensional material known for its applications in semiconductors and energy systems.

Using metal–organic chemical vapor deposition, they applied low-cost MoS2 nanosheet thin films onto stainless steel current collectors, offering a scalable and more affordable alternative to traditional noble metal coatings. During cycling, MoS2 undergoes a conversion reaction with lithium forming molybdenum metal and lithium sulfide (Li2S).

This dynamic interfacial layer acts as a buffer zone, improving lithium affinity and preventing the formation of dangerous dendrites. As a result, the battery lasts significantly longer and performs better than its uncoated counterpart.

In laboratory tests, cells with MoS2-coated current collectors maintained stable operation for over 300 hours, which is more than three times longer than those using bare stainless steel that short-circuited after about 95 hours.

Full-cell prototypes showed equally 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, increasing from 8.3 percent to 58.9 percent after 20 cycles.

“This is a core next-generation technology that could accelerate the commercialization of all-solid-state batteries across various applications,” Young-Kuk Lee, PhD, KRICT president said in a press release, adding that though still in early stages, the team expects the technology to be ready for practical use by 2032.

The study has been published in the journal Nano-Micro Letters.