Researchers at the National University of Singapore have developed a new solid-state sodium battery design that uses a low-cost additive to significantly improve performance, safety, and lifespan.
The main challenge with sodium-ion batteries has been safety and stability.
To address this, the researchers introduced graphitic carbon nitride (GCN), a material produced by heating urea at high temperature.
This helped reorganize the cell network, allowing sodium ions to move more efficiently. This improvement enhanced both conductivity and structural stability.
Performance tests showed that ionic conductivity more than doubled at elevated temperature, while ion transport efficiency also improved significantly. The modified system allowed a much larger share of charge-carrying ions to move through the battery during operation.
The strengthened electrolyte also reduced dendrite growth by creating a more uniform sodium deposition layer and improving resistance against penetration. As a result, battery durability increased sharply.
In testing, conventional polymer electrolytes failed within about 250 hours under low current conditions. In contrast, the modified version operated stably for over 1,000 hours at lower load and exceeded 2,000 hours under higher current conditions without failure.
The team also demonstrated full battery cells that retained high capacity after hundreds of charge cycles while maintaining very high efficiency. A flexible prototype continued to function even when bent and cut, highlighting improved safety and mechanical resilience.
Researchers say the next step is to optimize the technology for room-temperature operation and explore stacked designs to increase energy density further.
The study was published in the journal Advanced Functional Materials.
