Polyoxometalate Ionic Sponge Enabled Dendrite-Free and Highly Stable Lithium Metal Anode.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metallic lithium batteries offer high energy density but face safety challenges due to lithium dendrite formation.
• Uneven lithium-ion distribution leads to dendrite growth, compromising battery safety and cycle life.

Purpose of the Study:

• To investigate the efficacy of polyoxometalate (POM) clusters as an additive in conventional electrolytes for lithium metal batteries.
• To mitigate lithium dendrite formation and improve the cyclic performance and safety of lithium metal batteries.

Main Methods:

• Incorporation of a specific POM cluster, H5PMo10V2O40 (PMo10V2), into the electrolyte of lithium metal batteries.
• Evaluation of dendrite inhibition using Li/Li symmetric cells and performance assessment in Li/LiCoO2 (Li/LCO) full cells.

Main Results:

• The PMo10V2 additive successfully constructed a lithium-rich layer on the anode surface, ensuring uniform electric field distribution.
• Lithium dendrite growth was effectively inhibited, leading to a significantly prolonged cyclic lifespan for both symmetric and full cells.
• Li/LCO full cells with the POM additive maintained a high reversible specific capacity of 108.5 mAh g-1 after 300 cycles, compared to 31.5 mAh g-1 without the additive.

Conclusions:

• Polyoxometalate (POM) clusters, functioning as an "ionic sponge," can be effectively utilized to suppress lithium dendrites in lithium metal batteries.
• The developed POM-modified electrolyte demonstrates significant potential for enhancing the safety and longevity of next-generation energy storage systems.