Textile-based cathodes for lithium-ion batteries

Although much research into improving the energy density of lithium-ion batteries has been focused on anodes and high-voltage cathodes, less attention has been paid to designing electrodes with high surface areas, which is particularly important for practical storage devices.

Nam et al. report a technique for producing textile-based electrodes that are flexible, have a high surface area, and possess excellent electrical properties. In the past, this type of electrode has exhibited limited efficiency because of low mass loading.

The investigators used a layer-by-layer assembly method to create metal nanoparticle seeds. Polyester textile fibers were coated with these nanoparticles using a repetitive ligand exchange method. The composite was electroplated first with nickel and then aluminum to form aluminum-electroplated textiles, Al-ETs. The result was the first aluminum textile-based cathode.

“The aluminum electroplating step was conducted using an ionic liquid rather than an aqueous solution, because metals with a low standard reduction potential, such as aluminum, tend to react strongly with water to form a passivating oxide layer on the surface,” author Donghyeon Nam said.

The Al-ETs produced in this work had electrical conductivities that outperformed other available textile-type electrodes. The existence of both the layer-by-layer-assembled metal nanoparticle multilayer and the nickel layer with aluminum coating preserved the original structure of the 3D porous textile substrate even after electroplating. This allows for a high surface area containing many active sites and a high conductivity.

The highly flexible materials could be folded multiple times, achieving a high areal capacity, which is the area-normalized specific capacity. In addition, the investigators were able to create a similar type of anode and produce a functioning full-cell battery built entirely from electroplated textiles.

Source: “Aluminum textile-based binder-free nanostructured battery cathodes using a layer-by-layer assembly of metal/metal oxide nanoparticles,” by Donghyeon Nam, Minseong Kwon, Yongmin Ko, June Huh, Seung Woo Lee, and Jinhan Cho, Applied Physics Reviews (2021) The article can be accessed at https://doi.org/10.1063/5.0039990 .