Spurred by EVs and electrified aviation, global demand for lithium-ion batteries is expected to more than double its 2023 levels by 2030, far outstripping demand, according to S&P Global Insights. New batteries must be powerful, but also affordable enough for industry to adopt on a massive scale.
As a battery component, sulfur – low-cost, abundant and with a high theoretical specific capacity – seems tailor-made for the challenge. But so far, that theoretical capacity has stayed theoretical.
Chen-Jui (Ben) Huang is a co-author of a recent paper published in Nature Communications that’s cracking the code on sulfur, developing practical, powerful all-solid-state batteries using lithium-sulfur conversion chemistry. Huang is a postdoctoral researcher for the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) and University of California San Diego Nanoengineering department’s Laboratory for Energy Storage and Conversion (LESC) .
“Price-wise, sulfur is the ultimate inexpensive material that you want to put in the battery,” said Huang. “A key limitation of sulfur cathodes is that sulfur is intrinsically insulating, with negligible electronic conductivity and limited ionic transport. As a result, establishing continuous electron/ion percolation is challenging, and a significant fraction of sulfur can remain electrochemically inaccessible, making it difficult to realize the full theoretical capacity.”
By finding the perfect particle size for solid-state electrolyte powder and changing the fabrication strategy, the team created a sulfur-based composite cathode that delivers a discharge specific capacity of about 1500 milliampere-hours (mAh) per gram of sulfur. This puts science closer than ever to tapping sulfur’s theoretical capacity of 1675 mAh per gram. Furthermore, the team successfully demonstrated this performance in a practical pouch cell format, proving the technology's scalability and potential for real-world EV applications.
The work is the result of an ongoing industry-academia partnership with South Korean battery-maker LG Energy Solution through LG Energy Solution’s Frontier Research Lab (FRL) program.
“Instead of adding new materials or coatings, this work shows that simply arranging the existing materials more carefully allows sulfur to react much more efficiently,” said Seung Bo Yang, a Senior Researcher at LG Energy Solution and Visiting Industrial Fellow at LESC. “By optimizing particle size and how the materials are mixed, the battery can deliver high capacity, practical energy output in an all-solid-state design.”
This new research builds on the partnership’s prior lithium-sulfur work, part of their ongoing effort to combine solid-state batteries’ safety and stability with sulfur’s high capacity and low cost.
“High-performing batteries help no one sitting in labs. To hit our energy and climate goals, we need them out working in the real world. That means they must be affordable at scale,” said UChicago PME Prof. Shirley Meng, the first corresponding author of the new work. “This partnership between UChicago PME, UC San Diego and LG Energy Solution continues to show that low cost and high performance are not mutually exclusive. In fact, it’s the route we must pursue to create lasting real-world impact.”
One-step milling
One of the biggest reasons EV makers are exploring all-solid-state batteries is safety. If they crack from age or car crash, batteries with liquid components can get involved in thermal incidents.
“The intrinsic property of solid-state batteries is that we replace those flammable organic liquid electrolytes with non-flammable solid-state electrolytes,” Huang said. “Everything is dry, not a single drop of liquid.”
This means all three materials that go into a sulfur-based positive electrode – the sulfur active material, the solid-state electrolyte (SSE), and the conductive carbon – must be powders. Combining them is commonly done either by hand-mixing or through a multi-step milling process where the three are milled to powder separately, then combined.
Hand-mixing performed poorly and multi-step milling suffered from low utilization, implying the sulfur and SSE particles weren’t in close enough contact.
The team developed a one-step milling process where all three materials were ground to powder together. In addition to creating a uniform blend, it creates a metastable interphase that partially reacts the sulfide electrolyte with the sulfur cathode material, actually improving performance.
“By enabling higher energy density, this research points toward batteries that could allow electric vehicles to travel significantly longer distances,” Yang said.
One major finding was that the SSE particles must be on the micron level for peak performance.
“The particle size of the solid electrolyte matters, because you are combining solid particles with solid particles. So how they stack with each other, or how they can be packed the closest in the cell stack, that matters,” Huang said.
Other benefits
The paper also sets a plan to offset “breathing,” a phenomenon where materials expand and contract as they charge and discharge, adding stress and wear as the batteries cycle.
Sulfur-based electrodes “breathe” in the opposite way from the more common nickel–manganese–cobalt (NMC) electrodes: When sulfur tends to swell, NMC tends to shrink, and the reverse is also true. The researchers took advantage of this by pairing a silicon negative electrode with a lithium sulfide positive electrode. As the battery cycles, one side expands while the other contracts, so their volume changes partially offset each other and reduce the net change in stack thickness.
This complementary behavior helps the cell remain mechanically steadier and limits stress buildup. In practice, the team pairs Si with Li₂S, and lithiated Si (LiₓSi) with sulfur, so this out-of-phase volume-change mechanism is maintained across the relevant reaction states.
“Collaboration between industry and academia is essential to keep pace with the rapidly evolving battery market,” Yang said. “As demand for electric vehicles and energy storage grows, combining industry’s manufacturing expertise with innovative university research helps accelerate the development of next-generation battery technologies.”
Citation: “A highly utilized and practical lithium-sulfur positive electrode enabled in all-solid-state batteries,” Cronk et al, Nature Communications , February 27, 2026. DOI: 10.1038/s41467-026-69750-0
Nature Communications
A highly utilized and practical lithium-sulfur positive electrode enabled in all-solid-state batteries