Storage of Electrical Energy by a Redox Flow Battery Based on Cobalt and Iron Complexes with Amino-Alcohol Ligands in Strongly Alkaline Electrolyte

Physical Sciences : Materials and Compounds

Available for licensing


  • Allen Bard, Ph.D. , Chemistry and Biochemistry
  • Netz Arroyo , University of Texas at Austin

Background/unmet need

To further integrate renewable energy technologies, such as solar, wind and tide, to the current electrical grid and to provide demand response and other services to increase the reliability of the grid, there is a demand for electrical energy storage (EES) technologies that could regulate fluctuations in electricity supply and demand. 

Among the different EES alternatives, redox flow battery (RFB) are considered as a suitable technology to address this issue at both large scale and the domestic market. However, all the RFB technologies currently available suffer from technical and/or environmental issues that limit their applicability at a commercial scale.

Invention Description

UT Austin researchers have come up with a completely original idea of making an alkaline RFB, instead of the conventional acidic design. This alkaline system boasts better electrolyte stability and shelf life, less corrosion to cell components, and a simpler manufacturing process, while maintaining conductivity and voltage output comparable to commercially available acidic systems. 


  • No evolution of gases during charging/discharging electrodes
  • After 25 charge/discharge cycles, only 3% loss in capacity
  • Cost of electrolyte equal to or less than that of current vanadium-based technology


  • High concentration alkaline electrolyte
  • Chemically stable metal-organic complexes
  • One-step process to prepare the active redox species 

Market potential/applications

Utility scale electrical energy storage systems (WW TAM ~$200mm, projected to grow to $10.4B by 2017)

Development Stage

Lab/bench prototype

IP Status