Functionalized Polyethylene Separators with Efficient Li-Ion Transport Rate for Fast-Charging Li-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Fast-charging lithium-ion batteries (LIBs) are crucial for electric vehicles but are limited by separators with poor Li+ transport.
• Current separator technology presents a bottleneck in achieving high-performance LIBs for demanding applications.

Purpose of the Study:

• To enhance the electrochemical performance of traditional polyethylene separators.
• To develop a novel green binder for improved Li+ transportation rates in LIB separators.

Main Methods:

• Synthesized a novel green binder by grafting allyl alcohol ethoxylates (APEG) onto poly(acrylic acid) in an aqueous solution.
• Coated traditional polyethylene separators with Al2O3 nanoparticles using the synthesized green binder.
• Evaluated the electrochemical performance, electrolyte uptake, peeling strength, and Li+ transference number of the modified separators.

Main Results:

• The novel binder provides a homogeneous and stable separator structure with abundant functional groups facilitating Li+ transport.
• The modified separator achieved high electrolyte uptake (95.16%) and peeling strength (1.243 N cm-1).
• LIB cells using the optimized binder (10% APEG) showed significant capacity increases (34-40% at 10 C) compared to conventional binders.

Conclusions:

• The developed green binder effectively improves separator performance for fast-charging LIBs.
• This approach offers a promising pathway for developing advanced binder materials to overcome limitations in current LIB technology.
• The findings support the development of next-generation LIBs for electric vehicles and other high-power applications.