Nanoporous Adsorption Effect on Alteration of the Li⁺ Diffusion Pathway by a Highly Ordered Porous Electrolyte Additive for High-Rate All-Solid-State Lithium Metal Batteries

TLDR

Solid polymer electrolytes promise high energy density and flexibility for all‑solid‑state lithium metal batteries but suffer from low ionic conductivity and poor lithium metal stability. The authors propose a highly ordered porous electrolyte additive derived from SSZ‑13 to enable high‑rate all‑solid‑state lithium metal batteries. The additive, a SSZ‑13–based nanoporous composite incorporated into a PEO electrolyte, provides nanoporous adsorption that enhances Li⁺ transport and electrochemical stability. The SSZ‑CPE electrolyte achieves Li⁺ conductivity of 1.91 × 10⁻³ S cm⁻¹ at 60 °C, widens the stability window to 4.7 V vs Li⁺/Li, and delivers high‑rate capability and stable cycling in LiFePO₄/SSZ‑CPE/Li cells.

Abstract

Solid polymer electrolytes (SPEs) have shown extraordinary promise for all-solid-state lithium metal batteries with high energy density and flexibility but are mainly limited by low ionic conductivity and their poor stability with lithium metal anodes. In this work, we propose a highly ordered porous electrolyte additive derived from SSZ-13 for high-rate all-solid-state lithium metal batteries. The nanoporous adsorption effect provided by the highly ordered porous nanoparticles in the poly(ethylene oxide) (PEO) electrolyte is found to significantly improve the Li+ conductivity (1.91 × 10-3 S cm-1 at 60 °C, 4.43 × 10-5 S cm-1 at 20 °C) and widen the electrochemical stability window to 4.7 V vs Li+/Li. Meanwhile, the designed PEO-based electrolyte demonstrates enhanced stability with the lithium metal anode. Through systematically increasing Li+ diffusion, widening the electrochemical stability window, and enhancing the interfacial stability of the SSZ-composite electrolyte (CPE) electrolyte, the LiFePO4/SSZ-CPE/Li cell is optimized to deliver high rate capability and stable cycling performance, which demonstrates great potential for all-solid-state energy storage application.