The Safety Myth: Why “Next-Gen” Doesn’t Mean Risk-Free

The industry is obsessed with finding the “unburnable” battery. The narrative is simple: current lithium-ion tech is risky, and the next generation of chemistries – Solid State and Sodium-ion – will solve safety overnight.

The data tells a different story.

Recent Accelerating Rate Calorimetry (ARC) studies reveal that while new chemistries offer improvements, they are not the magic bullet many are hoping for. If we want to build safer systems, we need to stop relying on marketing myths and start looking at the thermodynamics.

1. The Thermal Hierarchy (It’s not what you think) When tested for thermal runaway onset temperatures – the point where a battery begins to self-destruct – the hierarchy is clear, and “new” doesn’t always mean “better”:

• LFP (Lithium Iron Phosphate): ~346°C (Safest)

• Sodium-Ion: ~292°C

• NMC (Nickel Manganese Cobalt): ~280–290°C

2. The Sodium-Ion Reality Check Sodium-ion is rightly praised for its stability and the ability to be transported at 0 Volts. However, it is not fireproof.

• The Risk: While its thermal runaway is less violent than NMC, it still occurs.

• The Gas Problem: Like its lithium counterparts, failing sodium cells release a cocktail of hydrogen, carbon monoxide, and toxic electrolyte vapors. It is a safer chemistry, but it still requires rigorous pack-level management.

3. The Solid-State “Holy Grail” The assumption that solid-state batteries are inherently safe is dangerous.

• Hybrid Hazards: Many “solid” batteries actually use polymer electrolytes or small amounts of liquid to improve conductivity – reintroducing flammability risks.

• The Dendrite Issue: Lithium metal anodes, often used to boost energy density in solid-state cells, are prone to dendrite growth. These microscopic spikes can pierce the solid separator, causing immediate short circuits.

The Bottom Line Changing the chemistry does not remove the risk. Safety is not a property of the material alone; it is an engineering challenge. Whether it’s Sodium, LFP, or Solid-State, the “safest” battery is the one built with the smartest architecture – not just the newest ingredients.

Inspiration for the text: chemistryworld.com