High temperatures and redox flow batteries
High temperatures can significantly impact the efficiency of redox flow batteries, particularly in terms of performance and longevity. Here’s a breakdown of the effects:
Efficiency and Performance
- Increased Voltage Efficiency: Higher temperatures typically enhance the kinetics of reactions within the battery, leading to improved voltage efficiency and peak power density. For example, increasing the temperature from 15°C to 55°C can boost voltage efficiency from about 86% to 90%.
- Improved Mass Transfer: Elevated temperatures enhance species mass transfer, which can improve battery performance by facilitating faster reactions.
- Reduced Viscosity and Pump Power: As temperatures rise, the viscosity of the electrolytes decreases, which reduces pressure drop and pump power consumption, making the system more efficient.
Negative Impacts
- Increased Activation Losses: High temperatures can increase activation losses, which negatively affect overall efficiency.
- Capacity Degradation: Higher temperatures accelerate capacity degradation and decrease coulombic efficiency. For instance, the coulombic efficiency might drop from about 96% to 94% when moving from lower to higher temperatures.
- Thermal Management: Managing heat is crucial as high temperatures can lead to overheating, especially during charging, and affect the stability and lifespan of the batteries.
Optimal Operating Range
To balance these factors, maintaining the operating temperature within a specific range (often between 10°C to 40°C) is recommended to ensure high efficiency, stability, and longevity while minimizing side reactions and electrolyte degradation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-high-temperatures-impact-the-efficiency-of-redox-flow-batteries/
