A Porous Li-Al Alloy Anode toward High-Performance Sulfide-Based All-Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Alloy/lithium-alloy anodes show better compatibility with sulfide solid electrolytes (SSEs) than lithium anodes for solid-state lithium batteries (ASSLBs).
• Developing stable and high-performance anodes is crucial for practical ASSLBs.

Purpose of the Study:

• To design and fabricate a porous lithium-aluminum (Li-Al) alloy anode (LiAl-p) for SSE-based ASSLBs.
• To investigate the electrochemical performance and interfacial properties of the LiAl-p anode.

Main Methods:

• Fabrication of porous Li-Al alloy anode using mechanical pressing.
• Characterization of anode structure and surface properties (e.g., porosity, oxygen species).
• Electrochemical testing of LiAl-p symmetric and full cells (e.g., critical current density, cycling stability, areal capacity).

Main Results:

• The LiAl-p anode exhibits a porous structure with abundant surface oxygen species.
• LiAl-p symmetric cells achieved a record critical current density of 6.0 mA cm⁻² and 5000 h cycling.
• LiAl-p|LiNi₀.₈Co₀.₁Mn₀.₁O₂ full cells delivered 11.9 mAh cm⁻² areal capacity and 1800 cycles.
• The porous structure accommodates volume changes, and a stable inorganic-rich solid electrolyte interphase (SEI) forms.

Conclusions:

• The porous Li-Al alloy anode demonstrates superior room-temperature performance in SSE-based ASSLBs.
• The unique architecture and surface chemistry facilitate volume change accommodation and stable SEI formation.
• This study provides a design strategy for high-performance alloy anodes in solid-state batteries.