Researchers in China have developed a new catalyst that helped a lithium-sulfur battery retain 93 percent of its capacity after 600 charge-discharge cycles, a step that could address one of the biggest barriers to commercializing the high-energy battery chemistry.

A team led by Professor Jie Sun at Shaanxi Normal University said the material, a titanium-chromium nitride solid-solution catalyst, was designed to trap and rapidly convert lithium polysulfides. These compounds are widely seen as the main cause of the shuttle effect that shortens battery life and lowers efficiency.

The researchers said the new design improved both long-term stability and reaction speed inside the battery. If scalable, the advance could support future use of lithium-sulfur batteries in electric vehicles, aviation systems and large-scale energy storage.

Lithium-sulfur batteries have drawn attention because they offer far higher theoretical energy density than conventional lithium-ion cells while using sulfur, a lower-cost and widely available material. The chemistry delivers a theoretical specific capacity of 1675 mAh g-1 and an energy density of up to 2600 Wh kg-1, significantly higher than lithium-ion batteries, making it a strong candidate for next-generation storage systems.

Atomic tuning works

The team produced flexible CNFs@TCN membranes using electrospinning and high-temperature nitridation. By adjusting the ratio of titanium and chromium precursors, they continuously tuned the catalyst’s electronic structure at the atomic level.

“The core innovation of this battery material research lies in our achievement of ‘precision tuning’ of the material’s electronic structure through continuous adjustment of the composition in TixCr1-xN solid-solution at atomic scale.”

Researchers said the material was not a simple mixture but a solid-solution phase engineered to improve catalytic behavior. Transition metal nitrides were selected because of their strong chemical interaction with polysulfides and their ability to facilitate electron transfer, both of which are critical for stabilizing lithium-sulfur batteries.

Modeling and experiments showed the best performance came when the titanium-to-chromium atomic ratio was 1:2. In that form, the catalyst delivered stronger adsorption of polysulfides and faster charge transfer than pure TiN or CrN. This optimized configuration allowed the material to balance chemical trapping with efficient electrochemical conversion.

That combination improved both the trapping of unwanted intermediates and their conversion during battery operation, directly targeting the root causes of capacity fade and poor cycling stability.

Strong cycle results

In performance tests, the CNFs@TCN-1/2 electrode delivered a specific capacity of 801 mAh g-1 and maintained 93% of its capacity after 600 cycles at 2 C. The reported capacity decay rate was 0.012 percent per cycle.

The figures suggest the catalyst can significantly suppress the shuttle effect while supporting stable long-cycle operation, two major challenges for lithium-sulfur batteries. The results also point to improved reaction kinetics, which are essential for maintaining efficiency during repeated charging and discharging.

“This work demonstrates that atomic-level doping via solid-solution construction is a powerful strategy for regulating the catalytic performance of transition metal nitrides.”

The team said the approach could also be used to design catalysts for other energy storage and conversion technologies, expanding its relevance beyond lithium-sulfur systems. If further developed, the strategy could contribute to more durable and efficient battery chemistries suited for large-scale clean energy deployment.

The study was published in the journal Nano Research.