This method promises to enhance battery safety, performance, and energy density, potentially doubling energy storage capacity and paving the way for more efficient, durable EV batteries.
Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have made strides in advancing solid-state battery technology. By utilizing a specialized polymer, the team has developed a thin, flexible film that could accelerate the development of next-generation solid-state batteries, particularly for electric vehicles (EVs). These batteries promise greater safety, performance, and energy density compared to current lithium-ion batteries that rely on flammable liquid electrolytes.
The newly developed solid-state electrolytes consist of durable sheets that separate the battery’s negative and positive electrodes, preventing electrical shorts while maintaining high ion conductivity. This innovation could potentially double energy storage to 500 watt-hours per kilogram, according to the team. The study builds on a previous ORNL invention, optimizing the polymer binder for sulfide solid-state electrolytes. The researchers aimed to achieve an optimal film thickness that balances ion conduction with structural integrity. Current solid-state electrolytes often use plastic polymers with lower conductivity than liquid electrolytes, sometimes requiring the incorporation of liquid components to improve performance.
Sulfide solid-state electrolytes, however, offer ionic conductivity comparable to that of liquid electrolytes, making them an attractive option for future batteries. The team discovered that the molecular weight of the polymer binder plays a critical role in the durability and effectiveness of the solid-state electrolyte films. Films made with longer polymer chains demonstrated better structural integrity and required less binder, which is advantageous as the binder does not conduct ions. Advanced characterization techniques such as scanning electron microscopy and nanoindentation were used to analyze the thin film’s microscopic structure and elemental composition.
Looking ahead, the team plans to integrate the thin film into next-generation battery electrodes and test its performance under real-world conditions. They also aim to collaborate with industry and academic partners to further develop and commercialize this technology.
