IMDEA Materials has developed a method to produce highly conducting nanostructured fabrics for use as current collectors or scaffold for active materials in composite electrodes for energy storage and conversion. Integration of these fabrics reduces electrode weight, improves cyclability/durability and improves the mechanical properties. This is the gateway to demonstrate the performance of new materials for free form, flexible electrodes without metallic current collectors using scalable processing.
This technology spans from the synthesis of nanostructured fabrics to the integration of active materials to the assembly as electrodes in electrochemical devices. A semi-industrial process is used for the fabrication of continuous fabrics of carbon nanotubes [1]. The current production capacity is in the tens of kilometers per day, in formats ranging from non-woven fabrics to yarns to transparent electrodes [2] (see Fig. 1).
Through simple solvent infiltration or gas-phase deposition methods, these porous networks can be combined with a wide variety of active materials, including inorganic materials for photocatalysis [3], capacitive deionization [4], lithium-ion battery electrodes [5], zinc-air battery electrodes [6] and supercapacitors [7]. Transition metal dichalcogenides, nitrides and polymers can also be easily incorporated into these porous fabrics.
IMDEA Materials expertise includes chemical treatments to increase compatibility between the conducting fabrics and the active material [8], advanced characterization methods to evaluated charge transfer/transport properties and in-situ structural studies during electrochemical conversion reactions [9]. Methods for fabrication of pouch-cell type devices up to 100 cm2 have also been developed [10] (see Fig. 2).
[1] Mikhalchan A, Vila M, Arévalo L, Vilatela J J. Simultaneous improvements in conversion and properties of molecularly controlled CNT fibres. Carbon 179, 417 (2021)
[2] Senokos E, Rana M, Vila M, Fernandez-Cestau J, Costa R D, Marcilla R, et al. Transparent and flexible high-power supercapacitors based on carbon nanotube fibre aerogels. Nanoscale 32 (2020)
[3] Moya A, Barawi M, Alemán B, Zeller P, Amati M, Monreal-Bernal A, et al. Interfacial studies in CNT fibre/TiO2 photoelectrodes for efficient H2 production. Applied Catalysis B: Environmental 268, 118613 (2020)
[4] C. Santos, I. Rodriguez, J Lado, M. Vila, E. García, M. Anderson, J. Palma JJV. Low-energy consumption, free-form capacitive deionisation through nanostructured networks. Carbon 176, 390 (2021)
[5] Rana M, Sai Avvaru V, Boaretto N, de la Peña O’Shea VA, Marcilla R, Etacheri V, et al. High rate hybrid MnO2@CNT fabric anodes for Li-ion batteries: properties and a lithium storage mechanism study by in situ synchrotron X-ray scattering. Journal of Materials Chemistry A 46 (2019)
[6] Pendashteh A, Palma J, Anderson M, J. Vilatela J, Marcilla R. Doping of Self-Standing CNT Fibers: Promising Flexible Air-Cathodes for High-Energy-Density Structural Zn–Air Batteries. ACS Applied Energy Materials 1, 2434 (2018)
[7] Senokos E, Reguero V, Palma J, Vilatela J, MARCILLA R. Macroscopic Fibres of CNTs as Electrodes for Multifunctional Electric Double Layer Capacitors: from Quantum Capacitance to Device Performance. Nanoscale 8, 3620 (2016)
[8] Iglesias D, Senokos E, Alemán B, Cabana L, Navío C, Marcilla R, et al. Gas-Phase Functionalization of Macroscopic Carbon Nanotube Fiber Assemblies: Reaction Control, Electrochemical Properties, and Use for Flexible Supercapacitors. ACS Applied Materials and Interfaces 10, 5760 (2018)
[9] Boaretto N, Rana M, Marcilla R, Vilatela JJ. Revealing the Mechanism of Electrochemical Lithiation of Carbon Nanotube Fibers. ACS Applied Energy Materials 3, 8695 (2020)
[10] Senokos E, Reguero V, Cabana L, Palma J, Marcilla R, Vilatela JJ. Large-Area, All-Solid, and Flexible Electric Double Layer Capacitors Based on CNT Fiber Electrodes and Polymer Electrolytes. Advanced Materials Technologies 2, 1600290 (2017)
