Multicomponent solid-solution alloy negative electrode for Li-metal batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries offer high theoretical energy density but face challenges with dendrite formation and limited cycle life due to low lithium utilization in conventional electrodes.
• Practical lithium metal batteries often use only 30-50% of the theoretical capacity to mitigate dendrite issues and improve stability.
• Developing stable and high-capacity lithium metal anodes is crucial for next-generation energy storage.

Purpose of the Study:

• To engineer a novel multicomponent solid-solution alloy for lithium metal anodes.
• To enhance lithium-ion transport and suppress dendrite formation in lithium metal batteries.
• To achieve high reversible capacity and long cycle life in practical battery applications.

Main Methods:

• Fabrication of a multicomponent alloy with ~90 wt.% lithium and equal atomic ratios of cadmium, silver, magnesium, and aluminum.
• Investigation of lithium-atom diffusivity and surface deposition mechanisms using entropy effects.
• Electrochemical testing of the alloy anode in pouch cells with a LiNi0.8Co0.1Mn0.1O2 cathode.

Main Results:

• The alloy exhibits high lithium-atom diffusivity and promotes a stable (110) crystal facet, leading to inward lithium transport.
• A dendrite-free anode with a high reversible specific capacity of 3100 mAh g⁻¹ was achieved.
• Pouch cells demonstrated high specific energy of 385 Wh kg⁻¹ and 82% capacity retention over 600 cycles.

Conclusions:

• The developed lithium metal alloy effectively suppresses dendrite formation and enhances lithium utilization.
• This alloy anode design offers a promising pathway for realizing safe, high-energy-density, and durable lithium metal batteries.
• The findings pave the way for practical applications of advanced lithium metal battery technology.