Atomically Intimate Solid Electrolyte/Electrode Contact Capable of Surviving Long-Term Cycling with Repeated Phase...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Achieving robust electrode-electrolyte contact is critical for all-solid-state lithium batteries.
• Current composite electrodes struggle with maintaining sufficient contact during cycling, limiting performance.

Purpose of the Study:

• To investigate epitaxy as a strategy to overcome electrode-electrolyte contact limitations in all-solid-state batteries.
• To demonstrate that epitaxial interfaces can maintain contact through electrode phase transitions.

Main Methods:

• Utilizing epitaxial growth to form interfaces between Li0.33La0.56TiO3 solid electrolyte and Li4Ti5O12/Li7Ti5O12 electrode materials.
• Analyzing the structural integrity and electrochemical performance of the composite electrode during cycling.

Main Results:

• Epitaxial growth facilitated atomically intimate contact between the solid electrolyte and both spinel (Li4Ti5O12) and rock-salt (Li7Ti5O12) phases.
• These epitaxial interfaces remained stable despite repeated spinel-to-rock-salt phase transitions during cycling.
• The epitaxially formed composite electrode exhibited rate capability comparable to conventional slurry-cast electrodes with solid-liquid contact.

Conclusions:

• Epitaxy is a viable strategy to achieve and maintain intimate solid-solid contact in composite electrodes for all-solid-state lithium batteries.
• The discovered epitaxial interfaces offer excellent long-term cycling stability, paving the way for high-performance solid-state batteries.