Technology

Agora’s technology

Technology

Agora owns the world-wide intellectual property for its unique flow battery technology, namely, the CO2 redox flow battery (CRB).

Agora’s battery system answers two of the most stringent priorities faced by our society: anthropogenic CO2 emissions and energy storage problems.

Our core technology enables the development of a low-cost, high-performance, long-lasting, temperature tolerant battery that uses large amounts of CO2 and converts it efficiently to energy.

WHAT is the CO2 REDOX FLOW BATTERY

Redox flow batteries are a class of electrochemical energy storage devices where chemical reduction and oxidation reactions (hence the name ‘redox’) that take place in the device enable the storage of energy. The name ‘flow’ refers to the fact that the electrolyte solutions are stored externally in separate tanks and flow continuously through a stack of electrochemical cells during operation.

One of the unique features of the CRB in the landscape of redox flow batteries is that, at battery negative electrode, the redox couple is CO2 and its organic carbonaceous derivatives.

HOW DOES THE CRB WORK?

The battery operates in successive cycling between a charging (storage) and discharging (electricity generation) states. In the charging cycle, electricity from renewable sources is supplied to the battery. At the cathode side of the battery, electrons are accepted via a reduction reaction and convert CO2 to a product which is the chemical storage medium for the battery. On the anode side of the battery, another redox couple release electrons and an oxidation reaction takes place producing a different chemical product. This movement of electrons closes the circuit in the storage stage of the battery. During the discharge cycle, i.e., the energy generation cycle, the direction of the current reactions and flows are reversed.

The CRB takes advantage of typical flow battery characteristics resulting from decoupling the battery pack containing the electrodes and separators from the active materials that are stored in separate containers.

Key Advantages

  • 100% depth of discharge is possible without damaging the electrodes
  • Fast and easy emergency shut-down without damage to the electrodes
  • Straightforward scale-up from kWh to MWh energy storage and generation
  • Minimal self-discharge on stand-by
  • Long service life
  • Low cost

FIGURES OF MERIT

Net Renewable Energy
Stored by the Battery
0.81 MWh/metric
ton CO2
Charge Current Density 2000 A/m2
Battery Charge Voltage 1.9 V
Discharge Current Density 3000 A/m2
Battery Discharge Voltage 0.75 V
Theoretical Energy Density
Wh/kg
550
Practical Energy Density
Wh/kg
500
Cycle Life
(Charge-Discharge)
>12,000
Price for negative electrode active material
USD/kg
CO2=0.02