Guiding Uniform Li Deposition through Interfacial Adsorption of Thin Polymer Films on the Anode for High Stability Lithium Metal Batteries

Abstract

The polymer protective layer on the lithium anode has received significant attention for flexibility, controllable synthesis, simple film fabrication, and structural versatility. However, the insulating properties of polymers and the unwanted dissolution of the polymer layer in the electrolyte greatly influence long-term cycle stability of lithium metal batteries. Here, we fabricated a polymer Guiselin brush via physical aging to solve the critical challenges and induce uniform Li deposition on the electrode. We first chose a polyester with fluoroalkane side chain (poly­(2,2,3,4,4,4-hexa­fluorobutyl methacrylate), PFMA) as the protective layer of the electrode. The results show that the PFMA Guiselin brush can induce uniform deposition of Li ions and greatly improve the Coulombic efficiency and cycle stability of batteries. The C–F bond of PFMA can easily break to form a component LiF that is beneficial to the solid–electrolyte interphase layer and effectively reduce the overpotential. In addition, different polymer protective layers were chosen, and the results show that all of these treated protective layers can improve the cycle stability of batteries. As a simple fabricating approach for polymers, the Guiselin brush is widely used and can be applied to other polymer chains. Therefore, this work proposes a facile, efficient, and general method to improve lithium deposition and battery performance.

Dual-functional mediators of high-entropy Prussian blue analogues for lithiophilicity and sulfiphilicity in Li–S batteries

“…In contrast, the HE-PBA@Cu/Li sample exhibits a stable voltage curve. 51 The amplified voltage curves in Fig. 6d, after a few cycles, highlight that the voltage hysteresis of HE-PBA@Cu/Li is ∼29.4 mV, maintaining long-term overpotential stability.…”