LATP-Enhanced Polymer Electrolyte for an Integrated Solid-State Battery

TL;DR

This paper introduces a new polymer electrolyte with added LATP to improve safety and performance in solid-state batteries.

Contribution

A LATP-enhanced polymer electrolyte and integrated architecture are proposed to enhance solid-state battery performance.

Findings

The PELT electrolyte achieved 1.2 × 10−4 S·cm−1 ionic conductivity at 60 °C and stable Li plating for over 600 h.

The integrated PELT/LFP battery retained 74% capacity after 200 cycles at 1 A·g−1 with improved rate capability.

Abstract

Traditional liquid electrolyte batteries face safety concerns such as leakage and flammability, while further optimization has reached a bottleneck. Solid electrolytes are therefore considered a promising solution. Here, a PEO–LiTFSI–LATP (PELT) composite electrolyte was developed by incorporating nanosized Li1.3Al0.3Ti1.7(PO4)3 fillers into a polyethylene oxide matrix, effectively reducing crystallinity, enhancing mechanical robustness, and providing additional Li+ transport channels. The PELT electrolyte exhibited an electrochemical stability window of 4.9 V, an ionic conductivity of 1.2 × 10−4 S·cm−1 at 60 °C, and a Li+ transference number (tLi+) of 0.46, supporting stable Li plating/stripping for over 600 h in symmetric batteries. More importantly, to address poor electrode–electrolyte contact in conventional layered cells, we proposed an integrated electrode–electrolyte architecture by in situ coating the PELT precursor directly onto LiFePO4 cathodes. This design minimized interfacial impedance, improved ion transport, and enhanced electrochemical stability. The integrated PELT/LFP battery retained 74% of its capacity after 200 cycles at 1 A·g−1 and showed superior rate capability compared with sandwich-type batteries. These results highlight that coupling LATP-enhanced polymer electrolytes with an integrated architecture is a promising pathway toward high-safety, high-performance solid-state lithium-ion batteries.

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