Mitigating Concentration Polarization via Ion-Sieving Interlayer Towards Long-Life 510 Wh Kg^-1 Lithium Metal Pouch...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Uncontrolled ion transport in lithium-metal batteries causes concentration polarization and lithium dendrite growth.
• This hinders the development of high-energy-density batteries, especially at high current densities (≥3 mA cm⁻²).

Purpose of the Study:

• To develop an interfacial ion-sieving strategy for stable lithium-metal batteries.
• To immobilize anions and guide uniform lithium-ion transport using a novel interlayer.

Main Methods:

• Introduction of a poly(2-acryloyloxyethyltrimethylammonium chloride-co-polyethylene glycol monomethyl ether methacrylate) (PAP) interlayer on the lithium metal anode.
• Utilizing quaternary ammonium groups to anchor anions and polyether chains to facilitate lithium-ion transport.
• Testing the interlayer's performance in a 7 Ah pouch cell with a LiNi₀.₈Co₀.₁Mn₀.₁O₂ cathode.

Main Results:

• The PAP interlayer effectively suppressed anion migration and promoted homogeneous lithium-ion transport.
• Interfacial concentration polarization was mitigated, and lithium dendrite growth was inhibited, even at 5 mA cm⁻².
• A 7 Ah pouch cell achieved ultra-high energy density (510 Wh kg⁻¹) and stable capacity (84.2% over 180 cycles) under lean electrolyte and high current density (3 mA cm⁻²).

Conclusions:

• The ion-sieving strategy significantly enhances the stability and performance of lithium-metal batteries.
• This approach offers a promising solution for developing next-generation high-energy-density batteries.
• The PAP interlayer demonstrates potential for practical applications in stable and high-performance lithium-metal batteries.