Technology

Silver coating makes solid-state batteries five times crack-resistant

Friday 16 - 13:50

By: Dakir Madiha

Silver coating makes solid-state batteries five times crack-resistant

Researchers at Stanford University have developed an ultra-thin silver coating for solid electrolytes that boosts crack resistance nearly fivefold, tackling a key barrier to commercializing next-generation lithium-metal batteries. Published January 16 in Nature Materials, the breakthrough promises safer batteries with higher energy density and faster charging compared to current lithium-ion technology.

Solid-state batteries aim to replace flammable liquid electrolytes with durable ceramic materials like LLZO, composed of lithium, lanthanum, zirconium, and oxygen. These ceramics, while theoretically superior, suffer from micro-cracks during charge cycles that lead to failure. The Stanford team applied a 3-nanometer silver layer, then heated samples to 300 degrees Celsius, allowing silver atoms to diffuse 20 to 50 nanometers deep and replace smaller lithium atoms.

Dissolved silver ions, not metallic silver, proved key to hardening the ceramic and blocking crack initiation and propagation. Lead researcher Xin Xu, now an assistant professor at Arizona State University, noted this nanoscale doping transforms how fissures form on electrolyte surfaces, enabling robust solid electrolytes for advanced energy storage.

This protective approach suits real-world manufacturing, where stacking cathodes, electrolytes, and anodes inevitably creates surface imperfections that prove costly to eliminate entirely. Associate Professor Wendy Gu, the study's senior author, emphasized that a simple silver treatment realistically shields against lithium infiltration during rapid charging, preventing crack expansion.

Tests focused on localized sample areas rather than full cells, leaving scalability and long-term performance over thousands of cycles for future validation. Silver is not unique; larger metal ions like copper show promise, though less effectively, opening paths to sulfur-based electrolytes or sodium batteries that ease lithium supply strains.