Electrochemical Additive Manufacturing of Battery Electrodes and Surfaces with Spatially Controlled Wettability

• Justin kim, Biochemistry, University of Delaware

• Rachel Davidson, Chemistry and Biochemistry, University of Delaware

Our group is working to develop the idea of electrochemical additive manufacturing which leverages scanning electrochemical probe techniques to synthesize nanomaterials with spatial control for applications as rechargeable battery electrodes and to create surfaces with spatially controlled wettability for fog capture. 

Continued improvements in battery charging rates and lifespan are crucial towards continued growth of the electric vehicle market. Ion transport and the rate of (de)intercalation during (dis)charge play key roles in determining the practical limitations in charge rate which can be applied for a given battery system. Our goal is to 3D print cathode materials through electrocrystallization using scanning electrochemical cell microscopy (SECCM). Through this approach we aim to deposit crystalline cathode materials in defined geometries directly onto current collectors. This will allow us to define and minimize the diffusional pathways for ion transport. Current efforts have focused on developing bulk electrochemical pathways to synthesize crystalline cathode materials, given that traditional approaches have typically required high temperatures and pressures which is generally incompatible with scanning electrochemical probe methods. We have developed methods to synthesize MnxOy and VxOy structures and are working to translate these syntheses to the nanoscale in SECCM. 

We are also working  to design and fabricate a passive fog harvesting device that utilizes spatially controlled wettability to capture and direct the flow of fog droplets. The increasing need for freshwater, driven by population growth and increasing water pollution , calls for the development of efficient and sustainable water harvesting techniques. Current methods of producing freshwater include desalination, municipal wastewater treatment, and solar water purification . These methods require large amounts of energy, resources, and monetary investment. 

This device would operate using microfluidic channels that combine gradients in  Laplace pressure as well as wettability to passively harvest water from fog. The use of SECCM for the electrodeposition of channels, allows precise control over the electrodeposition of wettability patterns onto durable substrates like stainless steel and copper. This device, therefore, aims to provide a sustainable and durable solution to the global concern over freshwater water scarcity. Thus far we have developed bulk electrochemical pathways for growth of tetraethyl orthosilicate films with tunable wettability and are working to print these using SECCM.