Nanocellulose Modified Polyethylene Separators for Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium (Li) metal anodes face challenges in cycling stability and safety, hindering the commercialization of high-energy density batteries.
• Current battery technologies require advanced solutions to overcome these limitations.

Purpose of the Study:

• To develop a novel tri-layer separator for lithium metal batteries.
• To enhance the cycling stability and safety of these batteries.

Main Methods:

• A tri-layer separator was designed by laminating cellulose nanofiber (CNF) layers onto a plasma-treated polyethylene (PE) separator.
• The CNF layers were produced using a simple paper-making process.
• The separator's performance was evaluated for cycling stability and thermal safety.

Main Results:

• The 2.5 µm thick mesoporous CNF layer (≈20 nm average pore size) promotes uniform Li+ flux, stabilizing Li metal anodes and improving cycling.
• The tri-layer separator exhibits dimensional stability up to 200 °C, providing a thermal shutdown function.
• The design effectively addresses key issues in Li metal battery performance.

Conclusions:

• The nanocellulose-based tri-layer separator significantly enhances cycling stability and safety in Li metal batteries.
• This innovative separator design facilitates the development of high-energy density Li metal batteries.
• The study presents a promising strategy for advancing battery technology.