Spatially Confined LiF Nanoparticles in an Aligned Polymer Matrix as the Artificial SEI Layer for Lithium Metal Anodes

Abstract

The uncontrollable growth of lithium (Li) dendrites and the instability of the Li/electrolyte interface hinder the development of nextgeneration rechargeable lithium metal batteries. The combination of inorganic nanoparticles and polymers as the artificial SEI layer shows great potential in regulating lithium-ion flux. Here, we design spatially confined LiF nanoparticles in an aligned polymer matrix as the artificial SEI layer. A high dielectric polymer matrix homogenizes the electric field near the surface of lithium metal. Aligned pores with LiF nanoparticles promote the lithium-ion transport across the artificial SEI layer. The synergistic effect of the highly polar β-phase PVDF and LiF nanoparticles provides high stability over 900 h for the Li//Li symmetrical cell. Besides, a Li//LFP full battery equipped with this artificial layer shows good performance in the commercial carbonate electrolyte, demonstrating the great potential of this protective film in lithium metal batteries.

Solid Electrolyte Interphase Architecture for a Stable Li‐electrolyte Interface

“…The PVDF * HPF matrix displayed hierarchically aligned channels while the LiF nanoparticles were spatially confined in the channels (Figure 9a). [98] The toughness (Figure 9b) and strength of the HASEI layer could successfully inhibit the side reaction and suppress the growth of Li dendrites. Moreover, the ionic conductivity of the LiF@PPF layer was 6.92 × 10 À 4 S cm À 1 , suggesting a faster charge transfer process through the interphase (Figure 9c).…”

“…To further suppress the growth of Li dendrites and prolong the lifespan of the batteries, both the structure and composition of the HASEI layers are crucial. The structures of HASEI layers are designed into three types based on the study of IASEI and OASEI: organic and inorganic components overlapped layer by layer, [97] inorganic particles filled in the channels of the porous organic matrix, [98] and inorganic particles distributed in the organic matrix. [99] A dual-layered interphase layer [97] with a well-designed structure was constructed on Li metal anode by a spontaneous reaction (Figure 8a).…”

“…Cycling performance of the full cells. [98] (Copyright 2023, American Chemical Society). Cycling performance of the full cells.…”

Fundamentals of Li/CFxbattery design and application

“…Yu et al designed an artificial SEI with confined LiF nanoparticles in an aligned polymer matrix, which prevented a sustained reaction and shorten the ion transport path. 58 The LiF-rich SEI has attracted much attention in the field of Li metal batteries because it favours a long cycle life. 59 However, as a primary battery, cycle life is not a major concern in Li/CF x batteries.…”

Self-Purifying Primary Solvation Sheath Enables Stable Electrode–Electrolyte Interfaces for Nickel-Rich Cathodes

“…Lithium ion battery (LIB) and Li metal battery (LMB) − are becoming more important for electric vehicles because of their potential to achieve high energy densities and long lifespans . The rising demand for high energy density batteries necessitates more competitive cathodes .…”