A Highly Reversible, Dendrite‐Free Lithium Metal Anode Enabled by a Lithium‐Fluoride‐Enriched Interphase

Abstract

Metallic lithium is the most competitive anode material for next‐generation lithium (Li)‐ion batteries. However, one of its major issues is Li dendrite growth and detachment, which not only causes safety issues, but also continuously consumes electrolyte and Li, leading to low coulombic efficiency (CE) and short cycle life for Li metal batteries. Herein, the Li dendrite growth of metallic lithium anode is suppressed by forming a lithium fluoride (LiF)‐enriched solid electrolyte interphase (SEI) through the lithiation of surface‐fluorinated mesocarbon microbeads (MCMB‐F) anodes. The robust LiF‐enriched SEI with high interfacial energy to Li metal effectively promotes planar growth of Li metal on the Li surface and meanwhile prevents its vertical penetration into the LiF‐enriched SEI from forming Li dendrites. At a discharge capacity of 1.2 mAh cm−2, a high CE of >99.2% for Li plating/stripping in FEC‐based electrolyte is achieved within 25 cycles. Coupling the pre‐lithiated MCMB‐F (Li@MCMB‐F) anode with a commercial LiFePO4 cathode at the positive/negative (P/N) capacity ratio of 1:1, the LiFePO4//Li@MCMB‐F cells can be charged/discharged at a high areal capacity of 2.4 mAh cm−2 for 110 times at a negligible capacity decay of 0.01% per cycle.

Electrolytes Enriched by Crown Ethers for Lithium Metal Batteries

“…LiF is considered to be most effectively components for performance enhancement of Li metal battery. [ 37,38 ] Compared to other electrolyte systems, LiF is the largest component of Li salt in the SEI films with 15‐C‐5 contained electrolyte system (Figure S6b, Supporting Information). From these characteristics, it can be inferred that the 15‐C‐5 additive was not only beneficial to form smooth and dense SEI films, but also improve the content of LiF in SEI films, which are the major factor to improve long‐term performance of LMBs.…”

Advances in the Design of 3D‐Structured Electrode Materials for Lithium‐Metal Anodes

“…In view of their high energy densities, absence of memory effects, and high round‐trip energy efficiencies, conventional lithium‐ion batteries (LIBs) are widely used on scales ranging from compact electronic devices to grid systems [ 8,9 ] but are currently reaching their maximal capacity, as their specific/volumetric energy densities are limited by the use of heavy metal‐based active host materials. [ 10,11 ] The use of Li as a high‐energy active anode material is a possible solution to this problem, as this metal exhibits a high theoretical capacity of ≈3860 mAh g −1 and a low redox potential (−3.040 V vs the standard hydrogen electrode).…”

Rational Design of Multifunctional Integrated Host Configuration with Lithiophilicity‐Sulfiphilicity toward High‐Performance Li–S Full Batteries

“…[10,11] Taking account of the aforementioned issues in Li-S batteries, various strategies have been conducted in recent years. For the sake of solving the Li-dendrite problem on the anode, considerable efforts have been employed, such as electrolyte additives, [12] designing of stable artificial SEI, [13,14] and engineering excellent Li hosts to guide Li deposition. [15,16] Among these approaches, Li hosts with large surface areas and lithiophilic properties are expected to suppress the growth of Li-dendrite and endure the volumetric variation of the electrode.…”