Low-Cost Manufacturing of Safe, Long-Life Battery Materials Using Atomic Layer Deposition
Authors: King David M , Trevey James E , Lichty Paul R , Cho Sung-Jin , Dahlberg Kevin , Albano Fabio 
Published: February 2020

The benefits of producing particles with tailored interfaces using the atomic layer deposition (ALD) technique have been widely demonstrated in the field of energy storage. As mobility and portability requirements grow, so does the need for higher energy density materials, higher power density systems, and enhanced lifecycles of devices, all of which create additional stresses at interfaces within energy storage modules such as lithium-ion batteries, fuel cells, and supercapacitors.  It is now widely accepted that the interfaces of lithium-ion battery electrode materials can be highly dynamic in nature, and are the source of detrimental effects such as electrolyte decomposition, particle fracturing, crystal phase transformations and other causes of performance fade.  The next generation of energy storage devices will be designed and engineered with tailored interfaces, and the cost of ALD on particles has fallen to a price point that is compelling enough to be adopted into product development cycles for mobile and stationary power applications.

Here, we will discuss ALD methodologies and best-suited applications in an effort to clarify the most appropriate steps towards the industrialization of an ALD-enabled energy storage future.  There are many metrics with which to evaluate the adoption of ALD-enabled particles into any technology, however all can be distilled down to a cost per relevant unit basis. Typically a significant amount of technological input is required from the value chain to formulate the ALD value proposition in an unbiased manner.  In the case of energy storage applications, the final product must have a justifiably lower cost per energy unit per charge/discharge cycle, or $/Wh/cycle. For batteries, in order to arrive at the cost savings attributable to tailored interfaces, consideration must be given to the following three stages of ALD development:

Discovery and Demonstration - Determining the optimal ALD method and/or chemistry in coin and/or small pouch cells, and validating performance in cells of appropriate size and format for the market segment.

Pack/Module Performance – Comparing ALD-enabled battery performance to its base competitor battery

Manufacturing Considerations – Quantifying materials, labor and capital costs required to implement the optimized ALD process into a battery manufacturing line and manufacturing risks associated with how the ALD process is implemented

Ultimately the scientific and industrial community alike have still only scratched the surface of the ALD-enabled energy storage story.  Conventional ALD coatings such as Al2O3, TiO2 and ZnO have shown tremendous promise, while next generation coatings that have atomically-precise tailored compositions or morphologies remain under development.  Next generation coatings that can deliver higher conductivities suitable for advanced batteries can remove the perceived tradeoff between barrier coatings and performance.  ALD is a means to engineer an energy storage future on an atomic level, with the potential for revolutionizing the battery as we know it, and having the potential to significantly impact other energy storage and generation systems.