LiF ‐Rich Solid Electrolyte Interphase Formation by Establishing Sacrificial Layer on the Separator

The controlled manipulation of Li+ movement by treating a fluorinated self-assembled monolayer as a sacrificial layer (FSL) on a boehmite-coated polyethylene (BPE) separator is demonstrated to establish a robust SEI layer. Due to the introduction of the FSL, a LiF-rich SEI is rapidly generated and deposited onto the LMA surface after cell assembly and 1st cycle stage. AbstractThe formation of a stable solid electrolyte interphase (SEI) layer is crucial for enhancing the safety and lifespan of Li metal batteries. Fundamentally, a homogeneous Li+ behavior by controlling the chemical reaction at the anode/electrolyte interface is the key to establishing a stable SEI layer. However, due to the highly reactive nature of Li metal anodes (LMAs), controlling the movement of Li+ at the anode/electrolyte interface remains challenging. Here, an advanced approach is proposed for coating a sacrificial layer called fluorinated self-assembled monolayer (FSL) on a boehmite-coated polyethylene (BPE) separator to form a stable SEI layer. By leveraging the strong affinity between the fluorine functional group and Li+, the rapid formation of a LiF-rich SEI layer in the cell production and early cycling stage is facilitated. This initial stable SEI formation promotes the subsequent homogeneous Li+ flux, thereby improving the LMA stability and yielding an enhanced battery lifespan. Further, the mechanism behind the stable SEI layer generation by controlling the Li+ dynamics through the FSL-treated...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research