Lightweight, Efficient, and Flexible Expeditionary Freshwater Production Enabled by Intercalative Fa
Abstract
Approved for Public ReleaseFaradaic deionization (FDI) using flow-through electrodes containing redox-active cation intercalation ma,terials (CIMs) has demonstrated desalination of brackish water salinity with only 25% more energy consumption than thermodynamic min,imum, thus showing promise for desalination by expeditionary units where fuel demands commensurate with energy use could inhibit ope,rational readiness. However, present FDI demonstrations showing seawater desalination lacked continuous flow. While the PI?s past an,d preliminary work has shown that state-of-charge gradients caused by flowing electrochemistry can be minimized by using fluid recir,culation and that reactors of increased size can facilitate seawater desalination with continuous flow, the energy consumed to pump,feedwater through homogeneous electrodes results in impractically low energy efficiency. This barrier to scale-up motivates Objectiv,e 1 to investigate microchannel networks to enhance hydraulic permeability by >100X and to enhance salt diffusion by 10X-100X. To de,salinate seawater and brackish water, as motivated by expeditionary needs, requires CIMs to intercalate Na, Mg, Ca, and K ions, thou,gh CIMs for Na and K have been most readily used to date. This barrier to source flexibility motivates Objective 2 to produce resili,ent multivalent intercalation using a suite of inorganic and organic CIMs and inactive additives. Current FDI architectures that use, a single cell pair exhibit more than 100X increased mass relative to CIMs alone due to current collectors, end plates, and bolts th,at are used to package them. This barrier to lightweight systems motivates Objective 3 to integrate electrodes in vertical stacks to, scale-up water production capacity in 3D.We will use physics-based modeling to design microchannel networks with maximal hydraulic,permeability and facile salt diffusion. In concert experimental fabrication of such microchannels will result in manufacturing-aware, designs that push the limits of resolution and performance, culminating in experiments to quantify energy consumption and salt remo,val. CIMs ,scopic inactive materials will be incorporated into CIM synthesis processes and into electrode fabrication processes to facilitate e,fficient electron conduction and reversible multivalent intercalation. Cation-selective polymeric coatings will be used to suppress,side reactions, after which desalination experiments will be performed using simulated seawater and brackish water to characterize t,he impact of ion selectivity on desalinated water quality. Physics-based analysis will also be used to design vertically integrated,stacks to distribute water to individual electrodes and to suppress shunt currents within manifolds. Stack assembly will be done in,conjunction with impedance and flow testing to assure adequate compression, contact, and sealing between components. Desalination of, seawater and brackish water will be performed using a ten-cell stack prototype, the results of which will be used to validate a mul,ti-scale electrochemical model that will later be used to quantify energy consumption and system mass up to and including expedition,odynamic energy efficiency >50% and with a 10X reduction in mass relative to unstacked reactors. This research will also create enab,ling concepts and rational design principles for low-dissipation, flow-through FDI electrodes in lightweight up-scaled systems for p,otable water generation. Multi-scale modeling will introduce novel methods for the optimization of flow fields. The advances made by,ation systems for DoD use.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 13, 2022
- Source ID
- N000142212577
Entities
People
- Kyle C Smith
Organizations
- Office of Naval Research
- United States Navy
- University of Illinois Urbana–Champaign