Summary:Researchers have developed a bikitaite-infused cellulose separator that suppresses lithium dendrites, improves fast-charging performance, and significantly extends the lifespan of lithium-metal batteries.
Lithium-metal batteries have long been viewed as a breakthrough technology for electric vehicles and next-generation energy storage due to their exceptionally high energy density. However, safety risks caused by lithium dendrite growth have remained one of the biggest obstacles to commercialization.
A research team has now developed a new bikitaite-infused cellulose-based separator (CBT) that could help overcome this challenge. The study shows that the separator creates continuous three-dimensional lithium-ion transport pathways, enabling more uniform lithium deposition while reducing the formation of dangerous dendrites.
Figure 1：Schematic Diagram of CBT Separator Preparation Process
According to the research, the CBT separator achieved a lithium-ion transference number of 0.742 and an ionic conductivity of 3.45 × 10⁻³ S cm⁻¹, substantially higher than conventional polyethylene (PE) separators. These improvements accelerate ion transport, reduce polarization, and enhance battery charging efficiency.
Figure 2：Schematic diagram of Li⁺ ion flux comparison under PE and CBT separators
The technology also demonstrated exceptional durability. Lithium-metal symmetric cells operated for more than 2,200 hours with stable cycling, while lithium-metal batteries paired with high-nickel NCM90 cathodes retained around 60% of their original capacity after more than 2,500 high-rate charge-discharge cycles.
Figure 3：Schematic diagram of Li⁺ ion flux comparison under PE and CBT separators
Beyond cycle life, the separator offers significant safety advantages. Unlike conventional PE separators that shrink at elevated temperatures, the cellulose-based design maintained structural integrity even at 200°C, reducing the risk of internal short circuits.
The separator also performed well under extreme conditions. Tests at −25°C showed improved cycling stability and reduced dendrite formation, highlighting its potential for electric vehicles and energy storage systems operating in cold climates.
Figure 3：Comparison of Low-temperature Cycle Performance at -25°C
As global demand grows for fast-charging EV batteries, high-energy-density battery technology, and safer energy storage systems, the researchers believe the scalable cellulose-ceramic separator design could provide a practical pathway toward commercial lithium-metal batteries.
