Halogenation of para-aminophenol and polymerization of the halogenation product results in electro-conductive redox polymer. For example, the para-aminophenol is chlorinated or brominated in an acidic solution, and the halogenation product is polymerized upon increasing the pH and upon oxidation. The halogenation product can be polymerized during electro-deposition of a thin film upon an anode current collector from an electrolyte solution to produce a sensor electrode, and the halogenation product can be mixed with electro-conductive carbon material to produce electrode-active material for storage battery electrodes. For example, the sensor electrode has an electrochemical reduction potential and a charge-discharge cycle period inversely proportional to pH, and the storage battery electrodes are positive electrodes in a storage battery having zinc negative electrodes in a zinc salt electrolyte solution.

Provided are a positive electrode for a ZnBr battery, a ZnBr battery including the same, and a method of manufacturing the positive electrode for a ZnBr battery. The positive electrode for a ZnBr battery includes a carbon body doped with pyridinic nitrogen. The ZnBr battery includes a negative electrode including a transition metal coated with zinc, the positive electrode; and an electrolyte. A pH of the electrolyte is in a range of 1.5 to 5.

An energy storage system comprises a plurality of electrochemical cells. The electrochemical cells include a pair of electrodes including an anode and a cathode. An electrolyte in communication with the pair of electrodes. A flow shaping baffle is situated between the pair of electrodes. The flow shaping baffle includes a plurality of channels extending from a first end proximate the cathode to a second end proximate the anode along an axis substantially perpendicular to the electrodes. The first end has a first diameter and the second end has a second diameter. The first diameter is greater than the second diameter. The disclosed energy storage system does not require expensive pumps or ion exchange membranes and can operate efficiently over a long service life.

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.

Bipolar electrodes comprising a carbon felt loaded with a polymer material and a nanocarbon material are described herein. The bipolar electrodes are useful in electrochemical cells. In particular, the loaded carbon felt can be used in bipolar electrodes of zinc-halide electrolyte batteries. Processes for manufacturing the loaded carbon felt are also described, involving contacting (e.g., dipping) a carbon felt in a mixture of solvent, polymer material and nanocarbon material.

Disclosed in the invention is a zinc-iodine battery structure, which includes a housing, a cavity is formed in the housing, and a cation exchange membrane for dividing the cavity into two parts is disposed in a middle of the cavity; a glass fiber component for protecting the cation exchange membrane is disposed at a negative output end; a graphite felt impregnated with a ZnI.sub.2 solution is disposed on an outside of the glass fiber component; and the graphite felt of the negative output end is coated with Bi powder, and a graphite felt of a positive output end is coated with Sm powder. Carbon plates serving as current leading-out channels of a battery are disposed on outsides of the graphite felts; and a return flow channel is disposed between the two graphite felts. By using a homogeneous cation exchange membrane with a low electrical resistance, a problem of serious self-discharging is overcome; and by using a flow battery with an open flow system, a problem of a change in pressure caused by a change in volume during charging and discharging is effectively solved. By disposing glass fiber products on two sides of the cation exchange membrane, a dendritic crystal generated during charging is unable to reach a separator, so that short circuit caused by puncture of the separator is avoided.

Provided is a layered double hydroxide (LDH) separator comprising a porous substrate made of a polymeric material; and a LDH with which pores of the porous substrate are plugged. A central region along the thickness of the LDH separator has a lower mean porosity than peripheral regions along the thickness of the LDH separator.

Provided is a layered double hydroxide (LDH) separator including a porous substrate made of a polymeric material, and LDH with which pores of the porous substrate are plugged. The LDH separator has a plurality of remaining flattened pores, longitudinal directions of the pores being non-parallel to a thickness direction of the LDH separator.

Redox active polycyclic compounds and related electrode material, electrode chemical cell battery, methods and systems are described. In particular, tricyclic compounds having a redox potential of 0.20 V to 2.0 V with reference to Zn/Zn2+ electrode potential under standard conditions are described. More particularly, redox active monomers, dimers, and polymers in which each monomeric unit contains a tricyclic heterocyclic structure are provided as electrode material of a cathode for an electrochemical cell further containing a zinc anode and an aqueous electrolyte.

A chambered frame insert (2) for an electrolyte chamber of a battery (200) includes a plurality of ribs (4) laterally and defining a plurality of chambers (6), and a plurality of voids (8) each formed in a corresponding rib and configured to allow gas to travel between the plurality of chambers. The plurality of ribs are angled with respect to a horizontal lateral axis (H) of the frame insert.