3D Printed Electrodes for Efficient Membrane Capacitive Deionization
There is an increasing interest for cost-effective and energy-efficient technologies for desalination of salt water. However, scalability of suitable compositions’ electrodes has greatly hindered the development of Capacitive deionization (CDI) as a promising technology in desalination of brackish water. Herein, we introduce a 3D printing technology as a new route to fabricate electrodes with adjustable composition which enables large-scale applications as free-standing, binder free, and robust electrodes. The 3D printed electrodes are designed with ordered macro-channels which facilitate the effective ions diffusion. The high salt removal capacity of 75 mg g-1 was achieved for Membrane Capacitive Deionization (MCDI) using 3D printed Nitrogen-doped graphene oxide/ Carbon nanotube electrodes. The improved mechanical stability and strong bonding of the chemical components in the electrodes allow a long cycle lifetime for the MCDI devices. The adjusted operational mode (current density) enables low energy consumption of 0.331 Whg-1 and high energy recovery of ~ 27%. Furthermore, the results from finite element simulations of the ions diffusion behavior quantified the structure-function relationships of CDI electrodes.