Stabilizing Lithium Metal Anode Enabled by a Natural Polymer Layer for Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but face challenges from lithium polysulfide shuttle, volume expansion, and dendrite formation.
• These issues impede the practical application of next-generation Li-S batteries.

Purpose of the Study:

• To develop a protective coating for lithium anodes to overcome key limitations in Li-S battery performance.
• To enhance the stability and cycle life of lithium metal anodes.

Main Methods:

• An artificial conformal agar polymer coating was applied to the lithium anode (A-Li).
• Performance was evaluated using Li/Li symmetric cells and Li-Cu cells, alongside Li-S battery configurations.

Main Results:

• The A-Li anode demonstrated stable plating/stripping for over 300 hours at 3.0 mA cm^-2 and 3.0 mAh cm^-2.
• Li-Cu cells with A-Li showed doubled cycle life compared to pristine cells.
• Li-S batteries with A-Li anodes exhibited improved specific capacity and Coulombic efficiencies.

Conclusions:

• The agar polymer coating effectively accommodates volume expansion and suppresses lithium dendrite growth.
• This approach provides a viable strategy for protecting lithium metal anodes.
• The study contributes to advancing the development of high-performance Li-S batteries.