This invention relates to a cyclable laminar flow battery having flow-through porous electrodes along with a non-ion-perm-selective element called a “dispersion blocker” to inhibit local convection.
Laminar flow fuel cells are known in the prior art, which includes Ferrigno et al., J. Am. Chem. Soc., 2002, 124 (44), pp. 12930-12931; Choban et al., J. Power Sources 128, 54-60 (2004); Kjeang et al., US 2009/0092882; Peled et al., US 2012/0308907 and 2012/0308911; Braff, US/2012/0070766; and Cho et al., Journal of the Electrochemical Society, 2012. These cells are “membraneless” because laminar flow is used to keep reactants at one electrode from crossing over to the opposite electrode, without the use of a standard ion-perm-selective membrane barrier, as in most fuel cells and batteries.
These systems are mostly referred to as membraneless, laminar-flow “fuel cells” since they only support galvanic discharge operation and are not able to electrolytically recharge in closed-loop operation. Indeed, no prior flow battery system has been disclosed that can achieve stable closed-loop cycling with a membraneless laminar flow architecture. Most of the prior art also involves planar “flow-over” electrodes, although Cho discloses a flow-through cathode in a system with a solid ion exchange membrane. Most of the prior art also does not include attempts to control convection in the laminar flow channel, although Stroock et al., US 2008/0008911 and DaMota et al., Journal of the American Chemical Society 2012, disclose convection barriers in flow batteries that are not used with porous media or to inhibit dispersion.