When a battery sits in a car, energy per kilogram is the dominant virtue. When a battery sits in a steel box on a concrete pad next to a substation, the calculus inverts: weight is free, but fire risk, longevity and cost over a multi-decade life are everything. That inversion is the entire case for sodium-ion in grid storage.The National University of Singapore's US12080845B2, granted in September 2024, claims non-flammable sodium-ion batteries. The 'non-flammable' framing is the headline, and it is aimed squarely at stationary storage, where a fire in a dense installation of cells is the nightmare scenario — hard to extinguish, capable of cascading across an entire site.Does it pencil? For grid storage, increasingly yes. Sodium-ion's lower energy density is a near-non-issue when the asset does not move, and its cheaper, more abundant materials cut the upfront cost that dominates a storage project's economics. Add a credible non-flammability claim and you have addressed the operational risk that most worries site operators and insurers. The bargain — less energy density for more safety and lower cost — fits the application.The safety advantage is partly structural. Sodium-ion cells can typically be discharged all the way to zero volts without damage, which makes them safer to ship and store, and many sodium chemistries are inherently less thermally reactive than high-nickel lithium. A formulation engineered to be outright non-flammable pushes that inherent advantage further — valuable when hundreds of cells share a confined enclosure for years.The cost-of-fire math is what justifies accepting lower performance. A grid storage fire is not just lost equipment; it is downtime, regulatory scrutiny, insurance fallout and, in the worst case, danger to people and surrounding infrastructure. A chemistry that sharply reduces that tail risk earns a premium that does not show up in the energy-density spec sheet but very much shows up in the project's risk-adjusted return.For readers, this grant is another data point that sodium-ion is settling into its lane. It is not coming for the long-range EV, where lithium's density wins. It is positioning as the safe, cheap, durable chemistry for batteries that stay put — and for that job, non-flammability may matter more than any energy number.