Enhanced ion-electron mixing interface for high energy solid-state lithium metal batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state Li metal batteries (SSLMBs) offer enhanced safety and energy density.
• Poor interfacial contact in SSLMBs leads to high impedance and lithium dendrite growth.
• Addressing these interfacial issues is crucial for practical SSLMB applications.

Purpose of the Study:

• To introduce an ion-electron mixing (IEM) interface on Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) solid electrolytes.
• To improve interfacial contact and suppress lithium dendrite growth in SSLMBs.
• To enhance the cycling stability and performance of SSLMBs.

Main Methods:

• An ion-electron mixing (IEM) interface was created on LATP solid electrolyte surfaces via an in-situ reaction.
• The IEM interlayer formed Li_xSn/LiI, a fast lithium-ion conductor.
• Electrochemical performance was evaluated, focusing on cycling stability at various current densities.

Main Results:

• The IEM interlayer effectively generated a Li_xSn/LiI interface with promoted Li⁺ transmission and inhibited electronic conduction.
• SSLMBs with the IEM@LATP electrolyte demonstrated stable cycling for over 1000 hours at 0.1 mA cm^-2.
• The batteries maintained normal operation even at a high current density of 3.0 mA cm^-2.

Conclusions:

• The developed IEM interface successfully mitigates lithium dendrite growth and improves interfacial contact in SSLMBs.
• This approach offers a viable strategy for enhancing the performance and practical application of SSLMBs.
• The IEM strategy shows potential general applicability to other solid-state battery systems.