Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

High energy density redox flow device

A large stack redox flow battery system provides a solution to the energy storage challenge of many types of renewable energy systems. Independent reaction cells arranged in a cascade configuration are configured according to state of charge conditions expected in each cell. The large stack redox flow battery system can support multi-megawatt implementations suitable for use with power grid applications. Thermal integration with energy generating systems, such as fuel cell, wind and solar systems, further maximize total energy efficiency. The redox flow battery system can also be scaled down to smaller applications, such as a gravity feed system suitable for small and remote site applications.

Redox flow battery system for distributed energy storage

An automotive or other power system including a flow cell, in which the stack that provides power is readily isolated from the storage vessels holding the cathode slurry and anode slurry (alternatively called “fuel”) is described. A method of use is also provided, in which the “fuel” tanks are removable and are separately charged in a charging station, and the charged fuel, plus tanks, are placed back in the vehicle or other power system, allowing fast refueling. The technology also provides a charging system in which discharged fuel is charged. The charged fuel can be placed into storage tanks at the power source or returned to the vehicle. In some embodiments, the charged fuel in the storage tanks can be used at a later date. The charged fuel can be transported or stored for use in a different place or time.

Fuel system using redox flow battery

A reduction/oxidation (“redox”) flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

Cascade redox flow battery systems

A redox flow battery. A metal-ligand coordination compound including an aromatic ligand that contains an electron withdrawing group is used as the catholyte and/or the anolyte so that a redox flow battery having high energy density and excellent charge/discharge efficiency may be provided.

Redox flow battery

The present invention describes an improved membrane for Redox Flow Batteries, in particular for Vanadium Redox Batteries and energy storage systems and applications employing the Vanadium Redox Cells and Batteries. Redox Flow Batteries involve the use of two redox couple electrolytes separated by an ion exchange membrane that is the most important cell component.

Kazacos Nicholas Michael

Papers

Perfluorinated membranes and improved electrolytes for redox cells and batteries