Effect of Low-Temperature Al2O3 ALD Coating on Ni-Rich Layered Oxide Composite Cathode on the Long-Term Cycling Performance of Lithium-Ion Batteries

Abstract

Conformal coating of nm-thick Al 2 O 3 layers on electrode material is an effective strategy for improving the longevity of rechargeable batteries. However, solid understanding of how and why surface coatings work the way they do has yet to be established. In this article, we report on low-temperature atomic layer deposition (ALD) of Al 2 O 3 on practical, ready-to-use composite cathodes of NCM622 (60% Ni), a technologically important material for lithium-ion battery applications. Capacity retention and performance of Al 2 O 3 -coated cathodes (≤10 ALD growth cycles) are significantly improved over uncoated NCM622 reference cathodes, even under moderate cycling conditions. Notably, the Al 2 O 3 surface shell is preserved after cycling in full-cell configuration for 1400 cycles as revealed by advanced electron microscopy and elemental mapping. While there are no significant differences in terms of bulk lattice structure and transition-metal leaching among the coated and uncoated NCM622 materials, the surface of the latter is found to be corroded to a much greater extent. In particular, detachment of active material from the secondary particles and side reactions with the electrolyte appear to lower the electrochemical activity, thereby leading to accelerated capacity degradation.

Energy storage: The future enabled by nanomaterials

“…In this context, there are a few considerations that make nanomaterials important for advancing this technology. First, in case of the solid-state batteries with planar geometry, nanostructuring promises to control 2D interfaces between battery components by means of the incorporation of specifically designed interface layers with nanoscale thickness and the ability to suppress parasitic reactions between electrode and electrolyte or metal dendrite growth (23)(24)(25)(26)(27). Additionally, nanomaterials can be used to create specific battery components.…”

“…High-capacity conversion (sulfur and fluorides) and alloying (Si and Sn) materials undergo considerable structure changes and large volume expansion and contraction (19,20), which can cause mechanical and chemomechanical instability across the length scales of individual nanoparticles, electrodes, and full electrochemical cells (21,22). Coatings with nanoscale thickness obtained via atomic or molecular layer deposition may be needed to suppress parasitic interfacial reactions, including the growth of metal dendrites, and/or form an artificial solid-electrolyte interphase (SEI) layer leading to the improved stability of electrochemical cells (23)(24)(25)(26)(27). Achieving future advancements in this research area will require broadening the compositional chemistry of interfacial layers and developing nanotechnology approaches that would allow for pinhole-free coating of 3D architectures with varying porosity.…”

A highly efficient surface modified separator fabricated with atmospheric atomic layer deposition for high temperature lithium ion batteries

“…The process is quite different, unlike followed in hydroxyl group (‐OH)‐terminated inorganic substrates. First, the absorption of TMA takes place on the surface region of Celgard, which then reacts with H 2 O in the second step 27 . The reaction sequences of R2R‐ALD process to deposit single atomic layer is shown in Equations ) and ().…”

Surface Modification Strategies for Improving the Cycling Performance of Ni‐Rich Cathode Materials

“…Furthermore, oxide coatings can act both as HF barrier and scavenger . Typical examples include Al 2 O 3 ,, , TiO 2 , , and ZrO 2 , . Oxide coatings based on tungsten, boron, cobalt, silicon and tin have also been reported.…”