Lignin Derived Ultrathin All-Solid Polymer Electrolytes with 3D Single-Ion Nanofiber Ionic Bridge Framework for High...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state lithium batteries offer enhanced safety over liquid electrolyte counterparts.
• Developing stable and efficient solid electrolytes remains a key challenge.
• Biobased materials present a sustainable alternative for battery components.

Purpose of the Study:

• To develop an ultrathin, biobased composite polymer electrolyte (CPE) for solid-state lithium-ion batteries.
• To investigate the electrochemical performance and stability of the novel CPE.
• To explore the potential of lignin-derived materials in advanced battery technologies.

Main Methods:

• Fabrication of an ultrathin CPE using electrospinning/spraying and hot-pressing.
• Incorporation of a lignin-based lithium salt (L-Li) and PVDF-HFP framework with PEO/LiTFSI filler.
• Assembly and testing of Li-symmetric and LiFePO4//CPE//Li cells.

Main Results:

• The ultrathin CPE (13.2 µm) exhibits a 3D nanofiber ionic bridge network.
• Li-symmetric cells show stable cycling over 6000 hours with minimal dendrite growth.
• LiFePO4//CPE//Li cells achieve over 700 cycles at 0.2 C with high initial capacity (158.5 mAh g⁻¹) at room temperature and good performance at -20 °C.

Conclusions:

• The novel biobased CPE facilitates uniform Li+ deposition and suppresses dendrite formation due to its ultrathin nature and ionic bridge network.
• The synergistic effect between L-Li and LiTFSI in PEO creates efficient 3D Li+ transport channels.
• This work offers a promising biobased strategy for developing high-performance ultrathin solid electrolytes for next-generation lithium-ion batteries.