Engineering Continuous Ion/Electron Channels in Mixed Ionic-Electronic Conductor for Solid-State Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state lithium metal batteries (SSLMBs) face challenges including stress, interfacial instability, and lithium dendrite growth.
• Existing lithium hosts struggle to provide efficient ion and electron transport, hindering performance.

Purpose of the Study:

• To design and develop a novel three-dimensional nanotubular mixed ionic-electronic conductor (MIEC) as an advanced lithium host for SSLMBs.
• To address stress accumulation, interfacial stability, and dendrite issues in SSLMBs.

Main Methods:

• Fabrication of a mechanically robust and electrochemically stable titanium nitride (TiN) nanotube array.
• Coating the inner surface of TiN nanotubes with an ion-conductive solid electrolyte interphase (SEI) to create the MIEC lithium host.
• Electrochemical characterization of SSLMBs utilizing the developed MIEC host.

Main Results:

• The novel MIEC host facilitates lithium plating/stripping within the nanotubes via Coble creep.
• The TiN nanotube array provides robust structural support and consecutive ion/electron transport channels.
• Uniform lithium deposition inside the nanotubes was achieved, leading to exceptional interfacial stability during cycling.

Conclusions:

• The developed MIEC, based on TiN nanotubes with an SEI coating, effectively hosts lithium metal.
• This approach significantly enhances the electrochemical performance and cycling stability of SSLMBs.
• The study offers valuable insights for designing advanced MIECs for high-performance solid-state batteries.