Chemically Recovered Lithium Dendrites Enabled by Gradient-Distributed Liquid Metal Particles in Composite Polymer...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-energy-density rechargeable batteries are crucial for modern technology.
• Lithium metal batteries with solid polymer electrolytes face challenges with dendrite growth and shorting.
• Existing methods primarily focus on suppressing dendrites rather than recovering them.

Purpose of the Study:

• To develop a novel gradient polymer electrolyte for effective lithium dendrite recovery.
• To address the shorting problem in lithium metal batteries by enabling dendrite repair.
• To enhance the cycling stability and safety of solid polymer electrolytes.

Main Methods:

• Introduction of Gallium-based liquid metal (LM) particles with depth-dependent content into polymer electrolytes.
• Creation of an asymmetric electrolyte configuration with LM-rich and LM-free layers.
• Utilizing spontaneous alloying reactions for dendrite recovery upon puncturing.
• Post-mortem analysis to examine dendrite structural deformation and alloy formation.

Main Results:

• Demonstrated full chemical alloying of penetrated lithium dendrites into spherical Li-LM alloys.
• Inhibited electrical percolation at the LM-free layer, preventing short circuits.
• Achieved ultrastable cycling in symmetric cells (>2000 hours) and Li/LiFePO4 full cells (>400 cycles with 99.86% average Coulombic efficiency).

Conclusions:

• The proposed gradient electrolyte design effectively recovers lithium dendrites via alloying, preventing battery failure.
• This approach offers a significant advancement over physical/chemical suppression methods for dendrite management.
• The findings highlight the potential of gradient designs and liquid metal integration in next-generation battery systems.