Disclosed are cathodes having electron-conductive high-surface-area materials, aqueous non-halide-containing electrolytes, secondary zinc-iodine energy storage devices using the same, and methods for assembling the same. The disclosed high-surface-area materials and the aqueous non-halide-containing electrolyte solutions can contribute together to the confinement of the active iodine species in the cathode and to the minimization of shuttle effects and self-discharging. The non-halide-containing electrolyte salts can facilitate preferential adsorption of the iodine species to the cathode material rather than dissolution in the aqueous electrolyte solution, thereby contributing to the confinement of the active iodine species.

A separator for a flowing electrolyte battery, and a method of forming such a separator, enable improved efficiency in a flowing electrolyte battery. The separator includes a sheet having a first surface and a second surface opposing the first surface. A first spacer element is disposed on the first surface, and a second spacer element is disposed on the second surface. The first spacer element is wider than the second spacer element in a direction that is both parallel to the first and second surfaces and perpendicular to longitudinal axes of the first and second spacer elements.

Zinc metal negative electrodes and aqueous electrolytes can be used in a rechargeable battery. The electrolyte can include zinc sulfate dissolved in water with a pH in the range of 0-7, and at least one additive for increasing ionic conductivity of the electrolyte, and/or buffering the pH of the electrolyte, and/or controlling morphology of a stripped/plated surface of the negative electrode. The electrolyte can decrease the likelihood of internal short circuits caused by volumetric expansion of the negative electrode and morphology changes after repeated cycling and penetration of zinc metal through a separator to a positive electrode.

Provided is a terminal assembly for an electrochemical battery comprising a terminal connector; a conductive flat-plate with an electrically conducting perimeter; an electrically insulating tape member; and a terminal bipolar electrode plate. The electrically insulating tape member is in between the conductive flat-plate and the terminal bipolar electrode plate such that the electrically insulating tape member does not cover the entire surface area of the conductive flat-plate. The electrically conducting perimeter enables bi-directional uniform current flow through the conductive flat-plate between the terminal connector and the terminal bipolar electrode plate. Also provided is a battery frame member for a static rechargeable battery comprising a liquid diversion system; a gutter; a sealing member; a gas channel; and a ventilation hole. Also provided is a static rechargeable electrochemical battery comprising a pair of terminal assemblies, at least one bipolar electrode interposed between the pair of terminal assemblies, and a battery frame member.

Provided is an electrolyte including a bromine complexing agent and a metal ion additive. The electrolyte is prepared by inputting zinc bromide (ZnBr.sub.2) salt, a bromine complexing agent, and a metal ion additive containing Mn to DI water. The bromine complexing agent prevents a crossover phenomenon by capturing bromine to alleviate self-discharge at a positive electrode, and the metal ion additive inhibits the formation of zinc dendrites on a negative electrode through an electrostatic shielding effect. Accordingly, battery performance may be improved by a synergistic effect generated in a positive electrode and a negative electrode by the bromine complexing agent and the metal ion additive.

The invention relates to a method of operating a zinc-bromine battery, especially at a high temperature, comprising adding 1-n-butyl-2-methyl-pyridinium bromide to the electrolyte of said battery, and charging or discharging said cell. Also provided is the use of 1-n-butyl-2-methyl-pyridinium bromide as an additive in a zinc-bromine battery operating at a temperature above 30 C., and an aqueous concentrate with high content of 1-n-butyl-2-methyl-pyridinium bromide.

Systems and methods pertain to minimal architecture zinc-bromine battery (MA-ZBB) designs which include a conductive carbon foam electrode disposed in a zinc-bromine electrolyte. The foam electrode generates and stores liquid bromine during a charging cycle of battery. A carbon cloth suspended in the electrolyte forms a zinc electrode. A self-discharge behavior of liquid bromine released from the foam electrode attacks any dendritic zinc creeping towards the foam electrode to create a self-discharging function for increased lifetime of the battery. The zinc-bromine battery does not include complexing agents, pumps and membranes, thus reducing cost and failure points and leading to a minimal architecture. Imaging techniques based on distinct colors associated with different concentrations of liquid bromine in the electrolyte are employed to detect battery operation and improve performance.

Disclosed herein is an electrolyte composition that includes zinc chloride, an alkali metal chloride, acetonitrile, and water.

The present invention provide a non-aqueous electrolyte for use in static or non-flowing rechargeable electrochemical cells or batteries, wherein the electrolyte comprises a first deep eutectic solvent comprises a zinc salt, a second deep eutectic solvent comprising one or more quaternary ammonium salts, and a hydrogen bond donor. Another aspect of the present invention also provides a non-flowing rechargeable electrochemical cell that employs the non-aqueous electrolyte of the present invention.

The present invention provides an aqueous electrolyte for use in rechargeable zinc-halide storage batteries that possesses improved stability and durability and improves zinc-halide battery performance (e.g., energy efficiency, Coulombic efficiency, and/or the like). One aspect of the present invention provides an electrolyte for use in a secondary zinc bromine electrochemical cell comprising from about 30 wt % to about 40 wt % of ZnBr.sub.2 by weight of the electrolyte; from about 5 wt % to about 15 wt % of KBr; from about 5 wt % to about 15 wt % of KCl; and one or more quaternary ammonium agents, wherein the electrolyte comprises from about 0.5 wt % to about 10 wt % of the one or more quaternary ammonium agents.