Composite Ionogel Electrodes for Polymeric Solid-State Li-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Achieving high energy and power density in rechargeable cells is crucial for applications like electric vehicles and portable electronics.
• Solid-state batteries offer potential safety advantages over conventional lithium-ion cells, but electrode design remains a significant challenge.
• High active material loading in electrodes is essential for practical energy density, yet difficult to achieve in solid-state systems.

Purpose of the Study:

• To develop a novel strategy for fabricating composite electrodes with high active material loading for solid-state lithium-ion cells.
• To investigate the performance of ionogel-derived solid-state electrolytes in enabling scalable fabrication of high-performance cells.
• To demonstrate the potential of these composite electrodes and electrolytes in achieving high capacity utilization and stable cycling.

Main Methods:

• Utilized ionogel-derived solid-state electrolytes (SSEs) to create composite electrodes.
• Tuned precursor and active material composition in composite lithium titanate electrodes.
• Fabricated and tested full polymeric solid-state cells incorporating composite anodes and lithium iron phosphate cathodes with ionogel SSEs.

Main Results:

• Achieved high active material loading (>10 mg/cm², ~9 mA/cm² at 1C) using a scalable approach.
• Demonstrated near-theoretical capacity utilization at C/5 rates in composite lithium titanate electrodes.
• Attained stable cycling at 5.85 mA/cm² (11.70 A/g) with over 99% average Coulombic efficiency at room temperature.
• Showcased a complete solid-state cell with stable cycling at a 1C rate.

Conclusions:

• Ionogel-derived SSEs provide a viable pathway for scalable fabrication of high-performance solid-state lithium-ion cells.
• The developed composite electrode strategy effectively addresses the challenge of high active material loading.
• These advancements pave the way for safer and more energy-dense solid-state batteries.