Investigating the structural evolution of lithium zirconium nitrochloride solid electrolytes for all-solid-state...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• All-solid-state batteries (ASSBs) are key for next-generation energy storage, offering improved safety and energy density over conventional lithium-ion batteries.
• Inorganic solid electrolytes, particularly amorphous halides, are a focus due to their potential for high ionic conductivity and stability.
• Anion-mixed strategies are mainstream for developing advanced amorphous halide solid electrolytes.

Purpose of the Study:

• To investigate the structure evolution and ionic conductivity of nitrogen-doped amorphous halide solid electrolytes (Li3xZrxCl4Nx).
• To elucidate the formation pathway and advantages of mixed-anion chemistry in dual-anion electrolytes.
• To evaluate the electrochemical performance and low-temperature stability of these novel electrolytes.

Main Methods:

• Synthesis and characterization of Li3xZrxCl4Nx amorphous solid electrolytes.
• In situ time-resolved synchrotron X-ray diffraction to study structural evolution during mechanochemical reactions.
• Ionic conductivity measurements at various temperatures.
• Electrochemical performance testing in ASSB configurations with LiIn negative electrodes.

Main Results:

• Achieved ionic conductivities up to 3.21 × 10^-3 S∙cm^-1 at 30°C for Li3xZrxCl4Nx electrolytes.
• Demonstrated that nitrogen incorporation is crucial for enhancing ionic conductivity and mechanical deformability.
• Revealed the formation pathway of the dual-anion electrolyte and the benefits of mixed-anion chemistry.
• Observed stable electrochemical performance over a wide temperature range, including low-temperature operation with LiIn electrodes.

Conclusions:

• The nitrogen-containing dual-anion amorphous solid electrolyte exhibits promising properties for ASSBs.
• Mixed-anion chemistry and nitrogen incorporation are effective strategies for developing high-performance solid electrolytes.
• These findings highlight the potential of anion-mixed designs for advancing safe and efficient energy storage solutions.