Bilayer Zwitterionic Metal-Organic Framework for Selective All-Solid-State Superionic Conduction in Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Solid-state batteries (SSBs) offer enhanced safety and energy density over conventional batteries.
• Current solid-state electrolytes (SSEs) struggle to meet the demanding operational needs of SSBs.

Purpose of the Study:

• To develop a novel metal-organic framework (MOF) with customized bilayer zwitterionic nanochannels (MOF-BZN) for high-performance SSEs.
• To address the limitations of existing SSEs in advanced SSB applications.

Main Methods:

• Design and synthesis of MOF-BZN featuring a rigid anionic MOF channel with grafted multicationic oligomers (MCOs).
• Characterization of MOF-BZN's ionic conductivity, Li+ transference number, and electrochemical stability.
• Fabrication and testing of an SSB utilizing the MOF-BZN SSE under demanding conditions.

Main Results:

• MOF-BZN demonstrated excellent Li+ conductivity (8.76 × 10-4 S cm-1) and a high Li+ transference number (0.75).
• The material exhibited a wide electrochemical window of up to 4.9 V.
• The resulting SSB achieved a specific energy of 419.6 Wh kg-1 under high cathode loading and limited lithium.

Conclusions:

• The bilayer zwitterionic MOF design offers a pioneering strategy for advanced SSEs.
• MOF-BZN presents a promising pathway for developing highly efficient and safe solid-state batteries.
• This approach overcomes key challenges in current solid-state electrolyte technology.