In Situ Dendrite Suppression Study of Nanolayer Encapsulated Li Metal Enabled by Zirconia Atomic Layer Deposition

Abstract

Progressing toward the emerging era of high-energy-density batteries, stable and safe employment of lithium (Li) metal anodes is highly desired. The primary concern with Li metal anodes is their uncontrollable dendrites growth and extreme sensitivity to parasitic degradation reactions, raising the alarms for battery safety and shelf life. Nanolayer protection encapsulation, which is conformal and ionically conductive with a high-κ dielectric property, can suppress the degradation and empower stabilization of Li metal. In this work, engineering of a zirconia (ZrO) encapsulation layer on Li metal enabled by atomic layer deposition (ALD) was employed and investigated for surface-enhanced dendrite suppression properties using in situ optical observations and electrochemical cycling. The ALD process involved a combination of plasma subcycle activation and thermal subcycle activation in increasing the surface functionalization and chemisorption sites for precursors to obtain highly dense and conformal deposition. The encapsulation of Li with ZrO ALD nanolayer further demonstrated excellent tolerance to atmospheric exposure for at least 1-5 h because of a conformal physical barrier, and excellent heat tolerance up-to 170-180 °C (close to Li melting point) and high rate capability due to thermal resistive property and high ionic transport property, respectively, of the ZrO ceramic. The results establish a technology transferable to other metal anode chemistries and offer a potential insight into carrying out solid-state electrolyte multilayer coatings with high processing temperature flexibility and thereby providing a leap in the advancing of a range of high energy density all-solid-state batteries.

Facile Generation of Polymer–Alloy Hybrid Layers for Dendrite‐Free Lithium‐Metal Anodes with Improved Moisture Stability

“…Besides, practical applications of LMAs are also limited by their strict assembly conditions (O 2 <1 ppm, H 2 O<1 ppm). Atomic layer deposition (ALD) technology has been employed to improve the air stability of lithium metal, such as with coatings of Al 2 O 3 and ZrO 2 . However, its high cost, the rather sophisticated process, and its poor ability to transport lithium ions hinder its large‐scale application and further development …”

“…Atomic layer deposition (ALD) technology has been employed to improve the air stability of lithium metal, such as with coatings of Al 2 O 3 [16] and ZrO 2 . [17] However,i ts high cost, the rather sophisticated process,a nd its poor ability to transport lithium ions hinder its large-scale application and further development. [18] Herein, we report afacile method to construct apolymeralloy hybrid layer on the Li metal surface (denoted as treated Li)t oi mprove performance and moisture stability.T his process simply involves dipping lithium metal into asolution of 0.1m SnCl 4 in tetrahydrofuran (THF), in which as imple chemical reaction occurs between Li metal and SnCl 4 to form the hybrid layer on the lithium metal surface.…”

Lithium metal anodes: Present and future

“…The atomic-layer deposition (ALD) and molecular-layer deposition (MLD) are also important methods in the preparation of artificial protective layers [80][81][82][83] . Cho and co-workers engineered a zirconia (ZrO 2 ) encapsulation layer, which has a high-κ dielectric property, on Li metal anode with ALD [84] . Dasgupta and co-workers proved that the deposition of ultrathin ZnO layer on the current collector by ALD can facilitate the initial Li nucleation, which controls the morphology and reversibility of subsequent cycling [85] .…”

Waterproof lithium metal anode enabled by cross-linking encapsulation

“…In this regard, many protective approaches have recently been proposed with a great progress achieved [21]. As a thickness-controllable film-forming technique, atomic layer deposition and extended molecular layer deposition have been corroborated to deposit conformal and compact thin coatings to efficiently block damp air [22][23][24]. In view of the actual production demands, functional polymer [25][26][27][28][29], alloys [30,31], inorganics [32][33][34], and composite encapsulation layers [35] are enormously prepared by directly coating via a facile solution-casting method or utilizing the in-situ reaction between the precursors and lithium metal [36].…”