Intermolecular Hydrogen-Bond Network Boosts Lithium-Bonding Kinetics in Solid-State Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Gel polymer electrolytes (GPEs) face challenges like low ionic conductivity, poor lithium-ion transference, and dendrite formation in lithium metal batteries (LMBs).
• These limitations hinder the practical application of GPEs in high-performance solid-state batteries.

Purpose of the Study:

• To enhance lithium-bonding kinetics in GPEs by incorporating hydrogen bonds.
• To improve ion transport, stabilize interfaces, and boost the overall performance of LMBs.

Main Methods:

• Introduction of hydrogen bonds into the GPE structure to modify intermolecular interactions.
• Characterization of ionic conductivity, lithium-ion transference number, and mechanical properties of the modified GPE.
• Evaluation of solid electrolyte interface (SEI) formation and stability during lithium plating/stripping.
• Testing of full cells with LiFePO4 cathodes for long-term cycling performance.

Main Results:

• The hydrogen-bonded GPE exhibited enhanced ionic conductivity (10.57 × 10^-4 S cm^-1) and a transference number of 0.609.
• The GPE facilitated the formation of LiF-rich SEIs with a Young's modulus of 3.2 GPa, preventing dendrite growth.
• Full cells demonstrated excellent cycling stability, retaining a specific capacity of ~102.3 mA h g^-1 after 1000 cycles at 3 C.

Conclusions:

• Hydrogen bonding effectively regulates ion transport and SEI formation in GPEs for LMBs.
• This approach offers a promising strategy for developing advanced, high-performance solid-state batteries.
• The study highlights the potential of tailored intermolecular interactions in designing next-generation energy storage solutions.