High Capacity Garnet-Based All-Solid-State Lithium Batteries: Fabrication and 3D-Microstructure Resolved Modeling

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Developing high-performance all-solid-state batteries (ASSBs) is crucial for next-generation energy storage.
• Optimization of the positive electrode is a key challenge in ASSB development.

Purpose of the Study:

• To create and characterize a novel, fully inorganic mixed positive electrode for ASSBs.
• To investigate the electrochemical performance limitations of this new electrode design using advanced simulations.

Main Methods:

• Fabrication of a mixed positive electrode using LiCoO2 and Ta-substituted Li7La3Zr2O12 (LLZ:Ta).
• Assembly and electrochemical testing of a complete ASSB cell with a Li metal anode and LLZ:Ta electrolyte.
• 3D reconstruction and microstructure-resolved continuum simulations of the positive electrode.

Main Results:

• A novel LiCoO2 + LLZ:Ta mixed cathode was successfully produced without sintering aids or conductive additives.
• The ASSB cell demonstrated 81% theoretical capacity utilization at elevated temperatures and 0.1 C discharge rate.
• Simulations accurately predicted high-temperature performance but failed to capture room-temperature performance loss.

Conclusions:

• Interface phenomena at the cathode active material/solid-electrolyte interface are identified as the primary cause of poor room-temperature performance.
• Microstructure-resolved simulations provide valuable insights into performance limitations and optimization potential for oxide-based ASSBs.
• This research offers critical guidelines for the future development and fabrication of advanced ASSBs.