Supercomputer finds lithium-titanium tweak to boost sodium-ion batteries for grids

Researchers at UC San Diego have used a supercomputer and artificial intelligence to improve sodium-ion battery materials, a step that could lower the cost of large-scale energy storage for power grids. The team used the Expanse supercomputer at the San Diego Supercomputer Center to study how small material changes inside a battery cathode could boost energy storage and extend battery life. Sodium-ion batteries are seen as a lower-cost alternative to lithium-ion cells because sodium is abundant and widely available. That makes them attractive for storing renewable energy from solar and wind farms, where cost is a major factor. But sodium batteries have struggled with lower performance and faster degradation than lithium-based batteries, especially under high-voltage use. Tiny tweaks, big gains To address that, scientists modified an existing sodium-based cathode material by adding small amounts of lithium and titanium. “These subtle changes turned out to matter a lot: the modified material could store more energy and remained stable even when the battery was pushed to higher voltages, a key requirement for getting more energy out of each charge,” explained Professor Shirley Meng of UC San Diego. “In lab tests, the improved cathode held significantly more charge and kept most of its capacity after many cycles, even under demanding high-voltage conditions that usually cause sodium materials to break down more quickly.” The challenge for researchers was understanding exactly why those minor chemical changes had such a large impact on performance. That is where Expanse came in. Using computing allocations through the U.S. National Science Foundation ACCESS program, the team ran large-scale simulations of sodium-ion movement through the material’s crystal structure during charging and discharging. AI speeds discovery The simulations relied on AI models known as foundation potentials, which can perform atom-level calculations faster and at lower cost than traditional com…