Hydrophobic lithium diffusion-accelerating layers enables long-life moisture-resistant metallic lithium anodes in practical harsh environments

Toward Dendrite-Free Metallic Lithium Anodes: From Structural Design to Optimal Electrochemical Diffusion Kinetics

“…Figure 10F displays the dense moist-air-stable polymer-LiF-alloy hybrid layer on the metallic Li (MASPLA-Li) through optimizing the upper thickness of PVDF-HFP layer. 15 As revealed by SFG, the hybrid MASPLA layer stabilized for more than 4 h under the humidity of ∼50 RH. Even after exposure for various times, the MASPLA-Li showed extended lifespan and lower overpotentials.…”

“…The surface chemical properties are important factors that affects the surface wettability. 6,15,146,147 Thus, recent studies have focused on the introduction of more lithiophilic sites on the carbon matrix, including the addition of metal oxide, metal particles and polymers. According to the Wenzel model, reasonable materials (Al, Cu, CNT, and NiO) with strong binding energy between molten Li and matrix materials may improve wettability.…”

“…Even though porous carbon materials have the advantages of structural diversity and tunable pore sizes, the number of lithiophilic sites in current collectors made from pure carbon materials are unsatisfactory since the lithium dendrite usually forms at the edges after several stripping/plating cycles. The surface chemical properties are important factors that affects the surface wettability. ,,, Thus, recent studies have focused on the introduction of more lithiophilic sites on the carbon matrix, including the addition of metal oxide, metal particles and polymers. According to the Wenzel model, reasonable materials (Al, Cu, CNT, and NiO) with strong binding energy between molten Li and matrix materials may improve wettability .…”

“…The ever-increasing dependency and demands on consumable electronics, electric vehicles (EVs), and smart grid storages have stimulated the rising demands for high-energy-density rechargeable batteries. − Although lithium-ion batteries dominate the current consumer markets, the capacities of cathodes and graphitic anodes have both reached bottlenecks. − Fortunately, the lithium metal anode has been regarded as the “Holy Grail” for high-energy-density batteries due to its unrivaled theoretical specific capacity (∼3860 mA h g –1 ), nearly 10 times higher than that of a graphite anode (∼372 mA h g –1 ), and lower electrochemical potential (∼−3.04 V) relative to the standard hydrogen electrode (SHE). − More importantly, the utilization of a Li metal anode broadens the range of applicable cathode materials, from lithium-rich intercalated cathodes (e.g., LiFePO 4 , LiCoO 2 , and LiNi x Co y Mn 1– x – y O 2 ) to lithium-free conversion cathodes (e.g., sulfur and air), for the realization of differing types of lithium batteries with higher energy densities (Figure A). − Due to these advantageous electrochemical properties, lithium metal batteries (LMBs) have the potential to reach the energy density milestone of 500 Wh kg –1 in the next few years to satisfy industrial goals and practical utilizations in EVs and grid energy storage. − …”

“…As detailed in Figure B, the localized electric field, the heterogeneous interfacial affinity, and the high desolvation barriers are responsible for the failure of the Li metal anodes. , Such a failure may cause low Coulombic efficiency (CE), shortened life-span, and even safety risks of fire and explosion in LMBs. ,− During the multistep lithium plating (Figure B), the lithium ion/atom has to overcome the sluggish kinetics due to the high barriers of desolvation, nucleation and diffusion, ,, which are the main causes of the random plating, dendrite growth and SEI failure . Currently, there is a lack of methods for manipulating the intrinsic nucleation and diffusion kinetics toward lateral growth of Li deposition.…”