Low-Cost, High-Strength Cellulose-based Quasi-Solid Polymer Electrolyte for Solid-State Lithium-Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state lithium-metal batteries promise higher energy density but face challenges with solid electrolytes, including low ionic conductivity, poor interface stability, and high costs.
• These limitations hinder the commercial viability of advanced battery technologies.

Purpose of the Study:

• To develop a cost-effective and stable quasi-solid composite polymer electrolyte (QPE) for solid-state lithium batteries.
• To enhance the ionic conductivity and interface performance of solid electrolytes.

Main Methods:

• Fabrication of a cellulose acetate-based quasi-solid composite polymer electrolyte (C-CLA QPE).
• Electrochemical characterization of LiFePO4 (LFP)|C-CLA QPE|Li batteries.
• Density Functional Theory (DFT) simulations to understand ion migration mechanisms.

Main Results:

• The C-CLA QPE achieved a high Li+ transference number of 0.85 and excellent interface stability.
• LiFePO4 (LFP)|C-CLA QPE|Li batteries showed remarkable cycle performance, retaining 97.7% capacity after 1200 cycles at 1 C and 25°C.
• DFT simulations indicated that partially esterified side groups in the cellulose acetate matrix facilitate Li+ migration and improve electrochemical stability.

Conclusions:

• The developed C-CLA QPE presents a promising, low-cost alternative for solid-state lithium battery electrolytes.
• The material's properties address key limitations of current solid electrolytes, paving the way for commercial application.
• This research offers a viable strategy for creating stable and cost-effective polymer electrolytes for advanced lithium battery systems.