Work

New Nitrate Additive Enabling Highly Stable and Conductive SEI for Fast‐Charging Lithium Metal Batteries

Year: 2024

Type: article

Abstract: Polyester‐based electrolytes formed via in situ polymerization, have been regarded as one of the most promising solid electrolyte systems. Nevertheless, it is still a great challenge to address the issue of their high reactivity with metallic lithium anode by optimizing the components and properties of solid electrolyte interphase (SEI). Herein, a new class of N‐containing additive, isopropyl nitrate (ISPN) that can be miscible with ester solvents is demonstrated, and a chemically stable and ion‐conductive LiF‐Li 3 N composite SEI is constructed. In addition, ISPN can induce the formation of anion‐enriched solvation structures and reduces the desolvation barrier of Li + , resulting in fast transport of Li + . With the addition of ISPN, ionic conductivity of the electrolyte has nearly doubled, reaching as high as 5.3 × 10 −4 S cm −1 . What's more, the LiFePO 4 (LFP)|ISPN‐PTA|Li cell exhibits exceptional cycle stability and fast charging capabilities, maintaining stable cycling for 850 cycles at 10 C rate. Even when paired with the high‐voltage cathode, the LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622)|ISPN‐PTA|Li cell achieves an impressive capacity retention of 97.59% after 165 cycles at 5 C. This study offers a novel approach for ester‐based polymer electrolytes, paving the way toward the development of stable and high‐energy Li metal battery technologies.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202409492