Multifunctional Chloride-Oxide Additive Enabling Simultaneous Ionic/Electronic Conduction for High-Rate...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Solid-state batteries face challenges with NCM cathodes, including poor electron transport and contact failure due to volume expansion.
• Traditional conductive additives are often rigid and brittle, leading to interface instability.

Purpose of the Study:

• To develop a multifunctional cathode additive for solid-state batteries.
• To improve the electrochemical and mechanical properties of NCM cathodes.

Main Methods:

• Synthesis of LiW₂O(₁₁-x)/₂Clₓ (x = 0.5-10) as a glass-ceramic composite additive.
• Characterization of the additive's electronic conductivity, ionic conductivity, and mechanical properties (Young's modulus).
• Fabrication and testing of all-solid-state batteries using the developed additive.

Main Results:

• LiW₂O₃.₅Cl₄ (C4W) additive demonstrated high electronic conductivity (1.86 S cm⁻¹) and moderate ionic conductivity (0.73 mS cm⁻¹).
• The additive's Young's modulus matched the solid electrolyte, reducing mechanical stress and improving interface stability.
• Batteries showed excellent cycling stability (81.31% retention after 10,000 cycles at 5C) and rate performance.

Conclusions:

• The multifunctional additive synergistically controls electrochemical and mechanical properties.
• This approach offers an effective alternative to traditional conductive additives for advanced solid-state batteries.