Applications and Advantages of Atomic Layer Deposition for Lithium-Ion Batteries Cathodes: Review

Abstract

Nowadays, lithium-ion batteries (LIBs) are one of the most convenient, reliable, and promising power sources for portable electronics, power tools, hybrid and electric vehicles. The characteristics of the positive electrode (cathode active material, CAM) significantly contribute to the battery’s functional properties. Applying various functional coatings is one of the productive ways to improve the work characteristics of lithium-ion batteries. Nowadays, there are many methods for depositing thin films on a material’s surface; among them, one of the most promising is atomic layer deposition (ALD). ALD allows for the formation of thin and uniform coatings on surfaces with complex geometric forms, including porous structures. This review is devoted to applying the ALD method in obtaining thin functional coatings for cathode materials and includes an overview of more than 100 publications. The most thoroughly investigated surface modifications are lithium cobalt oxide (LCO), lithium manganese spinel (LMO), lithium nickel-cobalt-manganese oxides (NCM), lithium-nickel-manganese spinel (LNMO), and lithium-manganese rich (LMR) cathode materials. The most studied processes of deposition are aluminum oxide (Al2O3), titanium dioxide (TiO2) and zirconium dioxide (ZrO2) films. The primary purposes of such studies are to find the synthesis parameters of films, to find the optimal coating thickness (e.g., ~1–2 nm for Al2O3, ~1 nm for ZrO2, <1 nm for TiO2, etc.), and to reveal the effect of the coating on the electrochemical parameters of batteries. The review summarizes synthesis conditions, investigation results of deposited films on CAMs and positive electrodes and some functional effects observed due to films obtained by ALD on cathodes.

Coating Effect of Various-Phase Alumina Nanoparticles on NCM811 Cathode for Enhancing Electrochemical Performance of Lithium-Ion Batteries

“…At the same time, the operation process is complex, and the coating preparation process requires to be carried out in multiple stages, as well as high requirements for operating parameters. In addition, the upper limit of deposition temperature is determined by the stability of other binders or reagents, which increases the requirement for reagent stability. − These issues all affect the wider application of the ALD technology in the modification of cathode materials. Therefore, we chose the high-energy ball milling method to obtain uniform alumina slurries and achieved alumina coating on the surface of the cathode material by simply mechanically mixing.…”

Atomic Layer Deposition Titanium Oxide Coating for C-Rate Improvement of Li-Ion Cathodes

“…1 At the same time, there are other ways of enhancing lithium-ion technology, namely modification of already available materials by doping the cathode structure with different metal atoms 3 or by applying thin protective layers on the electrode surfaces. 4 There are many methods for creating protective layers: the sol-gel method, chemical vapor deposition (CVD), atomic layer deposition (ALD), magnetron sputtering, etc. However, among all the presented methods, special attention should be paid to the ALD method.…”

“…However, among all the presented methods, special attention should be paid to the ALD method. 4,5 Compared to other methods, atomic layer deposition has many advantages, such as low synthesis temperatures, precise thickness control, coating composition and thickness uniformity. Synthesis cyclicality with self-limited reactions provide precisely set the coating thickness by controlling the number of ALD cycles, which makes it possible to monitor the trend of the film resistance change depending on its thickness.…”

“…The ALD application relevance in the LIB field is confirmed by already available studies of cathode synthesis and its coating by atomic layer deposition method; [5][6][7][8][9] our team also analyzed the literature about ALD application for cathode coating, which consider many compositions of coatings and regularities associated with their synthesis. 4 Based on the review, the titanium oxide protective coating, on par with aluminum oxide, has revealed its efficiency in preserving cathode capacity at elevated current strengths, high cycling potentials, elevated temperatures and long-term cycling. At the same time, the number of studies devoted to titanium oxide deposition is about 6 times fewer than those devoted to aluminum oxide.…”

“…For these reasons, a titanium oxide coating was chosen as the study object. 4 In particular, some scientific groups work with titanium oxide thin films [10][11][12][13][14][15][16][17][18] and complex films, which include titanium, 17,19 on cathode surfaces, but the presented works do not consider the temperature factor of applied coating, as well as its effect on the electrochemical characteristics of modified cathodes. Only the C.-T. Hsieh's and I. Bloom groups synthesized the titanium oxide coatings on the cathode surfaces at three (120, 150, and 180 °C) and two (100 and 150 °C) different temperatures, respectively, but did not describe the causes of the achieved effect and did not focus on it.…”