Amorphous Nitride-chloride Solid-State Electrolytes for High Performance All-Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• High-performance solid-state electrolytes (SSEs) are essential for advancing all-solid-state batteries (ASSBs).
• Amorphous SSEs offer advantages like grain-boundary-free structures for improved solid-to-solid contact and uniform ion flux.
• Current research focuses on developing novel SSEs for high-voltage applications.

Purpose of the Study:

• To develop and characterize a new class of SSEs based on a nitrogen-chlorine dual-anion framework.
• To investigate the structural transition from crystalline to amorphous phases and its impact on ionic conductivity.
• To evaluate the performance of these amorphous SSEs in high-voltage ASSBs with advanced cathodes.

Main Methods:

• Synthesis of nitrogen-chlorine dual-anion electrolytes with varying nitrogen content (Li_3x+0.1ZrN_xCl_4.1).
• Structural characterization to identify the transition to an amorphous phase (Li_1.3ZrN_0.4Cl_4.1).
• Electrochemical testing, including ionic conductivity measurements, oxidative stability assessment, and full-cell cycling performance with LiNi_0.83Co_0.06Mn_0.11O₂ (NCM83) cathodes.

Main Results:

• A structural transition to an amorphous phase was achieved by increasing N^3- substitution.
• The amorphous Li_1.3ZrN_0.4Cl_4.1 electrolyte exhibited enhanced Li⁺ conductivity (3.01 mS cm^-1) and improved oxidative stability (up to 4.8 V).
• Full cells demonstrated high reversible capacity (200.1 mAh g^-1 at 4.5 V), excellent capacity retention (95.1% after 150 cycles), and long-term cycling stability (>3000 cycles at 3 C).

Conclusions:

• Nitrogen-chlorine dual-anion amorphous electrolytes represent a promising alternative to traditional single-anion systems.
• The developed amorphous SSEs show excellent compatibility with high-energy NCM83 cathodes for high-voltage ASSBs.
• These findings pave the way for designing next-generation solid-state electrolytes for advanced battery technologies.