Dielectric-Tailored Space Charge Layer and Ion Coordination Structure for High-Voltage Polymer All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polymer electrolytes in all-solid-state lithium metal batteries face challenges with structural stability and interfacial ion transport at high voltages.
• These limitations hinder performance improvements, particularly for high-voltage applications.

Purpose of the Study:

• To enhance the performance of polymer all-solid-state lithium metal batteries by improving structural stability and ion transport kinetics.
• To achieve higher oxidative potentials and longer cycling life through the incorporation of a dielectric material.

Main Methods:

• In-situ polymerization of a composite solid-state electrolyte incorporating dielectric barium titanate (BaTiO3).
• Investigating the interaction between the polymer electrolyte's ether group and BaTiO3 to regulate lithium-ion coordination.
• Analyzing the effect of BaTiO3's spontaneous polarization on the cathode/electrolyte interface and space charge layer.

Main Results:

• The composite electrolyte achieved an oxidative potential exceeding 5.2 V due to regulated Li+ coordination.
• Barium titanate weakened the space charge layer effect, facilitating faster Li+ transport across interfaces.
• All-solid-state LiNi0.8Co0.1Mn0.1O2/Li batteries demonstrated ultra-long cycling lives of 1800 and 1300 cycles at 4.6 V and 4.7 V, respectively.

Conclusions:

• Dielectric materials play a crucial role in developing high-performance solid-state electrolytes.
• The incorporation of dielectric BaTiO3 offers a promising strategy for realizing high-voltage, long-life all-solid-state lithium metal batteries.