Emerging Applications of Atomic Layer Deposition for Lithium‐Ion Battery Studies

Abstract

Lithium-ion batteries (LIBs) are used widely in today's consumer electronics and offer great potential for hybrid electric vehicles (HEVs), plug-in HEVs, pure EVs, and also in smart grids as future energy-storage devices. However, many challenges must be addressed before these future applications of LIBs are realized, such as the energy and power density of LIBs, their cycle and calendar life, safety characteristics, and costs. Recently, a technique called atomic layer deposition (ALD) attracted great interest as a novel tool and approach for resolving these issues. In this article, recent advances in using ALD for LIB studies are thoroughly reviewed, covering two technical routes: 1) ALD for designing and synthesizing new LIB components, i.e., anodes, cathodes, and solid electrolytes, and; 2) ALD used in modifying electrode properties via surface coating. This review will hopefully stimulate more extensive and insightful studies on using ALD for developing high-performance LIBs.

Review—Multifunctional Materials for Enhanced Li-Ion Batteries Durability: A Brief Review of Practical Options

“…For example, the Mn dissolution rate from LMO is greater at high potentials (above 4 V vs. Li/Li + ) than at lower potentials (below 4 V vs. Li/Li + ), a fact which is inconsistent with the disproportionation concept, since the fraction of Mn 4+ cations in the LMO lattice increases with increasing potential. 13,17 While a very large number of studies in the literature report a variety of results on the oxidation state of Mn species in the negative or positive electrodes of cycled LMO-graphite cells, 11,[18][19][20][21] Mitigation measures for Mn dissolution.-Several mitigation measures for the dissolution of Mn ions and its consequences were proposed in the literature over the past two decades: electrolyte optimization by a judicious choice of additives; [26][27][28][29][30][31][32][33] elemental substitutions in the LMO lattice, 7,13,17,34,35 in order to increase the average oxidation state of the Mn ions; surface coatings on the active material powder or electrodes, in order to avoid direct contacts between electrode and electrolyte solution, and thus prevent HF and other acid attack on the active material; [36][37][38][39][40][41][42] chemically active binders; [43][44][45][46][47][48][49][50] an inorganic Mn ions scavenging barrier layer such as lithium titanate 51 or a solid Li-ion conducting and Mn ions blocking membrane 52 placed in the inter-electrode space; and the utilization of chemically activ...…”

“…[36][37][38][39][40][41][42] The role of the coating is to prevent direct contact between the active material particles and the electrolyte solution, and thus eliminate or at least impede HF and other acid species' attack on LMO. Besides preventing acid attack, surface oxide coatings may also impart structural stability to the spinel through the formation of solid solution layers.…”

Growth of crystalline Al2O3 via thermal atomic layer deposition: Nanomaterial phase stabilization

“…Since some of the uses for ALD Al 2 O 3 films include gate oxide for electronics, 3,4 protective barriers, 5 as well as potential coatings in energy materials, [6][7][8][9][10] it is critical to characterize these coatings on the nanoscale. For example, in the case of energy materials, there are recent reports of enhanced stability and extended cycling of Li-ion battery nanomaterials coated with ALD Al 2 O 3 thin films, [6][7][8][9][10] 9 This work assumes that the Al 2 O 3 coating is amorphous, as would be expected. However, it has also been noted that since the Al 2 O 3 coating should be insulating, there is an issue with the Li atom and electron diffusion, which should degrade the performance, in contradiction of the reported results.…”

Novel Surface Coating Strategies for Better Battery Materials

“…ALD is a surface-controlled process, in which the deposition of films is dictated by alternative selfterminating and gas-solid surface reactions. 29 By the ALD method, atomic scale ultrathin coatings (usually in several nanometers) with excellent uniformity, flexibility and conformity can be easily obtained. The thickness of the deposited layer can be controlled by adjusting the ALD cycles.…”