Next-Generation Lithium Metal Anode Engineering via Atomic Layer Deposition

Abstract

Lithium metal is considered to be the most promising anode for next-generation batteries due to its high energy density of 3840 mAh g(-1). However, the extreme reactivity of the Li surface can induce parasitic reactions with solvents, contamination, and shuttled active species in the electrolyte, reducing the performance of batteries employing Li metal anodes. One promising solution to this issue is application of thin chemical protection layers to the Li metal surface. Using a custom-made ultrahigh vacuum integrated deposition and characterization system, we demonstrate atomic layer deposition (ALD) of protection layers directly on Li metal with exquisite thickness control. We demonstrate as a proof-of-concept that a 14 nm thick ALD Al2O3 layer can protect the Li surface from corrosion due to atmosphere, sulfur, and electrolyte exposure. Using Li-S battery cells as a test system, we demonstrate an improved capacity retention using ALD-protected anodes over cells assembled with bare Li metal anodes for up to 100 cycles.

Electrochemically Stable Coating Materials for Li, Na, and Mg Metal Anodes in Durable High Energy Batteries

“…The compound that is nearest in composition to Na-beta alumina in the OQMD is Al 2 O 3 , which did not pass our screens. However, we did identify four ternary Na-Al-O compounds that passed the screens, including NaAlO 2 , Na 7 Al 3 O 8 , Na 5 AlO 4 , and Na 17 Al 15 O 16 . This finding of Na-Al-O coatings for Na anodes differed from our finding for Li anodes, where no ternary Li-Al-O compounds passed our screens.…”

“…These coatings typically range between one nanometer and one micrometer in thickness. [14][15][16][17] Similar to passivation layers, these coatings should be durable and electronically insulating to block transfer of electrons. Unlike passivation layers, these coatings can be deposited at elevated temperatures from a variety of precursors, allowing for greater control of coating characteristics.…”

Electrolytes for electrochemical energy storage

“…Surprisingly, compared to the active and dynamic research on electrode materials, research on electrolytes received relatively less attention. [13][14][15][16][17][18] Electrolyte is an indispensable constituent, liquid in most cases, in all types of EES devices and helps conduct electricity by means of the transportation of ions, but not electrons. Because the electrolyte is placed between, and in close interaction with the positive electrode (positrode) and…”

Structural Design of Lithium–Sulfur Batteries: From Fundamental Research to Practical Application

“…One of the most effective and widely used methods to protect the lithium metal is to coat a protective layer on the surface to act as a physical barrier to against lithium dendrite formation and dissolved polysulfides [202,[300][301][302][303][304]. Porous Al 2 O 3 with 0.23, 0.58 and 0.73 mg cm −2 coating layers were fabricated to suppress the side reactions between the Li anode and PS species by using a spin-coating method.…”

“…In this regard, the Li-S batteries assembled with ALD-coated anodes showed a high discharge capacity retention of around 90% over 100 cycles (calculated based on the initial discharge capacity of ~ 1200 mA h g ), while only 50% discharge capacity was retained for the unprotected Li. Unfortunately, when the sulfur loading further increased to 5 mg cm −2 , the Li-S cells with ALD-coated Li anode lost nearly 40% of their 4th cycle capacity after 100 cycles [202].…”