Ultrathin and Air‐Stable Lithium Metal Anodes with Superlong Cycling Life in Ether/Ester‐Based Electrolytes

Abstract

Ultrathin and air‐stable Li metal anodes hold great promise toward high‐energy and high‐safety Li metal batteries (LMBs). However, the application of LMBs is technically impeded by existing Li metal anodes with large thickness, high reactivity, and poor performance. Here, we developed a novel and scalable approach for the construction of a 10‐μm‐thick flexible and air‐stable Li metal anode by conformally encapsulating Li within a multifunctional VN film. Specifically, the highly lithiophilic VN layer guides a uniform deposition of Li, while abundant and multilevel pores arising from assembly of ultrathin nanosheets enable a spatially confined immersion of metallic Li, thus ensuring an ultrathin and sandwiched Li anode. More impressively, the strong hydrophobicity of VN surface can effectively improve the stability of anode to humid air, whereas the highly conductive framework greatly boosts charge transfer dynamics and enhances Li utilization and high‐rate capability. Benefiting from such fascinating features, the constructed Li‐VN anode exhibits ultrastable cycling stability in both ether (2500 h) and carbonate (900 h) electrolytes, respectively. Moreover, even exposed to ambient air for 12 h, the anode still can retain ~78% capacity, demonstrating excellent air‐defendable capability. This work affords a promising strategy for fabricating high‐performance, high‐safety, and low‐cost LMBs.

Ultrathin Composite Li Electrode for High‐Performance Li Metal Batteries: A Review from Synthetic Chemistry

“…constructed an ultrathin and air‐stable composite Li electrode (≈10 µm) by conformally encapsulating Li metal in a multifunctional VN film (Figure 12c). [ 56 ] The highly lipophilic VN can contribute to the uniform Li deposition, meanwhile, the abundant pore structure from the assembly process of ultrathin nanosheets offers limited space for the Li metal to soak, thus achieving the ultrathin and filled composite Li electrode. More importantly, the intrinsic hydrophobicity of the VN surface effectively ensured the air stability of composite Li electrode.…”

“…Reproduced with permission. [ 56 ] Copyright 2022, Wiley‐VCH GmbH. d) Schematic of the fabrication process of ultrathin composite Li electrode with eGF host.…”

“…c) Schematic illustration of the preparation process of the ultrathin and air-stable composite Li electrode with VN host. Reproduced with permission [56]. Copyright 2022, Wiley-VCH GmbH.…”

Bidirectional Interphase Modulation of Phosphate Electrolyte Enables Intrinsic Safety and Superior Stability for High-Voltage Lithium–Metal Batteries

“…The ever-growing energy demand for electric transport stimulates the exploration of advanced battery technologies with high energy density and intrinsic safety. Owing to the highest theoretical capacity (3860 mAh g –1 ), lowest redox potential (−3.04 V vs SHE), and tiny density of 0.534 g cm –3 , the lithium metal anode (LMA) has been recognized as the ultimate anode for next-generation energy storage systems. − Particularly, developing high-voltage lithium metal batteries (LMBs) by pairing LMAs with high-voltage cathodes can dramatically improve the energy density up to 500 Wh/kg, which has been the aggressive goal of electric vehicle batteries . However, the serious safety concerns stemming from the poor thermal stability, easy flammability of conventional carbonate-based organic solvents, and inferior cycling stability resulting from the poor compatibility of commercial electrolytes toward both the highly reactive Li anode and high-voltage cathodes unavoidably impede the practical applications of high-voltage LMBs.…”

Air-Stable Lithium Metal Anodes: A Perspective of Surface Engineering from Different Dimensions

“…Despite the aforementioned progress, there is still an urgent issue that needs to be addressed for Li metal anodes to be suitable for practical applications: that is, air stability. − In other words, how to obtain an air-stable Li metal anode and ensure that its chemical/​electrochemical properties remain unchanged under short-term exposure to air, which is highly required and determines the practical possibilities of Li metal anodes, meaning stronger operability, but this has received much little attention. When exposed to ambient air, Li metal anodes suffer from severe atmospheric corrosion, especially the reaction with H 2 O, forming a thick passivation layer on the electrode surface, which not only hinders the development of Li–air batteries with high energy density but also leads to serious safety hazards and can even cause explosions, especially for high-capacity pouch cells .…”