CHINESE scientists have developed a groundbreaking liquid electrolyte that solidifies the moment a battery overheats. This creates an internal “firewall” that extinguishes potential fires before they can start, marking a major leap forward in battery safety.

The research, recently published in the journal Nature Energy, represents the world’s first demonstration of sodium-ion batteries at a commercial scale that can completely prevent thermal runaway — the dangerous chain reaction where a battery’s temperature rises uncontrollably, often leading to explosions.

For years, the industry believed that battery fires were caused primarily by the liquid electrolyte catching fire. To combat this, researchers focused on developing non-flammable liquids.

However, the research team challenged this convention. They discovered that even with flame-retardant liquids, batteries could still suffer severe thermal runaway. The true culprit, they found, was the separator — a thin plastic membrane that keeps the positive and negative sides of a battery apart. When that membrane melts, it causes a short circuit, triggering a series of heat-releasing side reactions.

Using this discovery, the team created a “polymerizable” electrolyte — a liquid that can turn into a solid, plastic-like substance when triggered. The electrolyte uses two specific sodium salts: sodium tetrafluoroborate and sodium hexafluorophosphate. These salts form protective films on the battery’s electrodes, improving both lifespan and safety.

Here is the critical safety mechanism: If a battery reaches a temperature of 150°C, the liquid electrolyte rapidly hardens into a solid. This physical barrier blocks all interaction between the positive and negative electrodes, effectively shutting the battery down safely before a fire can start.

To prove the technology’s reliability, researchers conducted two rigorous tests. In the first, they drove a steel nail directly through the battery to simulate an internal short circuit. In the second, they placed the battery in an oven heated to 300°C. In both scenarios, the sodium-ion battery produced no smoke, fire or explosions.

(SD-Agencies)