Polymer-Nanodomains Regulation for Optimized Ionic Translocation Enabling High-Voltage and Practical Utility Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-voltage solid-state lithium metal batteries (HVSSLMBs) promise advanced energy storage but face challenges from cathode degradation due to reactive oxygen species (ROS) and limitations of current polymer electrolytes.
• Degradation mechanisms include lattice oxygen oxidation at high voltages and poor ionic conductivity/electrochemical stability of polymer electrolytes.

Purpose of the Study:

• To design a composite polymer electrolyte (CPE) that overcomes the limitations of existing electrolytes for HVSSLMBs.
• To improve the chemical stability and ionic conductivity of electrolytes for high-voltage applications.

Main Methods:

• Developed a CPE using precise polymer-nanodomain engineering to create dual-domain-coupled secondary nanoconfinement.
• Engineered a structure with a mesoporous framework, dynamic segmental motion, and interconnected ion channels.
• Anchoring domains with high negative surface potential were utilized to preload lithium ions and enhance local ion density.

Main Results:

• The nanoconfined system significantly improved the polymer's chemical stability, enabling stable high-voltage operation.
• Cells using the CPE with a 4.8 V LRMO cathode retained 80.37% capacity after 200 cycles.
• A large-format pouch cell achieved an energy density of 419.47 Wh kg⁻¹ with a 4.61 Ah capacity.

Conclusions:

• The developed CPE effectively protects against degradation, enabling stable high-voltage operation in HVSSLMBs.
• This advancement represents a significant step towards the practical application of HVSSLMBs.
• The study demonstrates the potential of nanoconfinement strategies for next-generation battery electrolytes.