Fluorinated hybrid solid-electrolyte-interphase for dendrite-free lithium deposition

Abstract

Lithium metal anodes have attracted extensive attention owing to their high theoretical specific capacity. However, the notorious reactivity of lithium prevents their practical applications, as evidenced by the undesired lithium dendrite growth and unstable solid electrolyte interphase formation. Here, we develop a facile, cost-effective and one-step approach to create an artificial lithium metal/electrolyte interphase by treating the lithium anode with a tin-containing electrolyte. As a result, an artificial solid electrolyte interphase composed of lithium fluoride, tin, and the tin-lithium alloy is formed, which not only ensures fast lithium-ion diffusion and suppresses lithium dendrite growth but also brings a synergistic effect of storing lithium via a reversible tin-lithium alloy formation and enabling lithium plating underneath it. With such an artificial solid electrolyte interphase, lithium symmetrical cells show outstanding plating/stripping cycles, and the full cell exhibits remarkably better cycling stability and capacity retention as well as capacity utilization at high rates compared to bare lithium.

Electrochemically Active Red P/BaTiO3‐Based Protective Layers Suppressing Li Dendrite Growth for Li Metal Batteries

“…The impedance spectra were fitted using an equivalent circuit model in the inset of Figure 4e to estimate the values of R SEI and R ct . [ 11b ] The fitted values of R SEI and R ct were presented in Table S1 (Supporting Information).…”

“…[ 9 ] In particular, physical protective layers have been intensively explored as one of artificial SEI layers to stabilize Li metal. Various physical protective layers were prepared using organic polymers, [ 10 ] inorganic materials, [ 11 ] and their mixture forms, such as composite protective layers. [ 12 ] In the case of composite protective layers, electrochemically inactive ZrO 2 , [ 12a ] LiF, [ 12b ] and Al 2 O 3 [ 12c ] were conventionally used as inorganic fillers to improve the mechanical strength of protective layers.…”

In Situ Construction of a LiF‐Enriched Interface for Stable All‐Solid‐State Batteries and its Origin Revealed by Cryo‐TEM

“…The increase in R ct is due to possible side reactions at the interface that destroy the Li metal and SPE, and lead to the formation of unstable SEI. [41,58,59] When Li 2 S existed in the SPE, the R ct was smaller than that of the pure PEO-LiTFSI electrolyte both before and after circulation, which originated from the improved solid-solid interfacial contact, the effective control of side reactions, and the stabilized LiF-rich SEI. [60,61] In addition, the R ct of PEO-LiTFSI-Li 2 S batteries gradually increased in the initial cycles (190 Ω for 10 cycles) and declined in the following cycles (Figure 7f).…”

“…The following decrease of R ct can be contributed to high ion conductivity, low diffusion barrier, and high surface energy of LiF-rich interface, which can allow sufficient Li + transport and decrease the R ct . [58,62,63] In general, the strategy of introducing Li 2 S can effectively engineer the stable interface and boost the performance of electrochemical operation. The obviously improved performances of PEO-LiTFSI-Li 2 S based battery were attributed to the favorable interfacial stability of Li/PEO in battery.…”

Progress and Perspective of Constructing Solid Electrolyte Interphase on Stable Lithium Metal Anode

“…In addition, by controlling gas pressure and reaction temperature, the LiF film with a controllable thickness can be achieved. Recently, Pathak et al (2020) have reported an artificial SEI composed of LiF, Sn, and the Sn-Li alloy with the thickness of 25 µm on the Li surface by treating the Li metal with a SnF 2 -containing electrolyte. This hybrid SEI layer facilitates the Li ion diffusion and Li storage via FIGURE 2 | (A) Schematic diagram of lithium surface with a pinhole-free and tightly connected Li 3 N film , adapted with permission from American Chemical Society (B) Schematic diagram and synthesis process of lithiophilic-lithiophobic gradient CNT interfacial layer (Zhang et al, 2018), adapted with permission from Nature Publishing Group.…”