Invention Reference Number
ORNL has developed a new hybrid membrane to improve electrochemical stability in next-generation sodium metal anodes. The membrane material is composed of a porous substrate and sodium exchanged Nafion—a common ionomer—and offers improved mechanical qualities in addition to its resistance to capacity fade in sodium metal batteries.
Sodium metal batteries are a low-cost alternative to lithium, largely due to sodium’s relative abundance. These batteries also hold significant promise in long-term energy storage because of their potential for longer life cycles and faster charging. However, there are some major hurdles to using sodium-ion batteries, prominently the instability of traditional electrode/electrolyte interfaces in such batteries, which causes capacity fade over time. To address this hurdle, ORNL has created a new membrane material capable of sustained cycling in a sodium-metal-based battery.
ORNL’s new hybrid material integrates sodium exchanged Nafion, which provides excellent conductivity and selectivity, and an inert porous substrate. The addition of a porous substrate to the material significantly improves its electrochemical stability against sodium metal. Furthermore, the methodology used to create the material is generalizable to battery systems using other alkali metal anodes for similarly improved electrochemical stability. These advances promise to dramatically improve the feasibility of sodium metal and other alkali metal battery technologies.
Applications and Industries
- Battery manufacturers
- Long-duration energy storage
- Greatly improved electrochemical stability when using alkali metal anodes
- Sodium offers significantly reduced material costs compared with lithium