Flow batteries and lithium-ion batteries differ significantly in cost and efficiency, making them suitable for different energy storage needs.
Cost Comparison
- Material Cost: Lithium-ion batteries have a higher material cost per kWh (about $200) compared to flow batteries ($150/kWh), meaning flow batteries use cheaper active materials.
- Installation and Maintenance: Flow batteries incur higher installation and maintenance costs—about 60% more for installation ($8,000 vs. $5,000) and 50% more for maintenance ($300 vs. $200)—than lithium-ion systems.
- Scaling Effects: Flow batteries become more cost-effective at larger scales because increasing capacity mainly involves expanding the electrolyte volume, which is relatively inexpensive. Lithium-ion batteries, in contrast, get more expensive as they scale since more costly cathode materials are needed.
Efficiency Comparison
- Energy Efficiency: Lithium-ion batteries typically have higher round-trip efficiencies, ranging from 85% to 95%, while flow batteries generally achieve about 70% to 85% efficiency. One quantitative analysis found lithium-ion batteries to be about 12.5% more efficient than flow batteries.
- Energy Density: Lithium-ion batteries provide much higher energy density (often >200 Wh/kg), making them more space efficient and suitable for mobile applications. Flow batteries have lower energy density, limiting their use mostly to stationary grid or large-scale storage where space is less of a constraint.
Lifespan and Durability
- Flow batteries excel in longevity with lifespans often exceeding 20 years and over 20,000 full charge-discharge cycles with minimal degradation. Lithium-ion batteries generally last around 10–15 years or about 10,000 cycles in stationary applications, with gradual capacity loss over time.
Summary Table
| Feature | Flow Batteries | Lithium-ion Batteries |
|---|---|---|
| Material Cost ($/kWh) | ~$150 | ~$200 |
| Installation Cost | Higher (~$8,000) | Lower (~$5,000) |
| Maintenance Cost | Higher (~$300) | Lower (~$200) |
| Efficiency (%) | 70–85 | 85–95 |
| Energy Density | Low | High (>200 Wh/kg) |
| Lifespan (years) | 20+ years, 20,000+ cycles | 10–15 years, ~10,000 cycles |
| Scaling Cost Trend | Becomes cheaper at larger sizes | Becomes more expensive when larger |
| Safety | Safer, low risk of thermal runaway | Higher risk of thermal runaway |
In essence, flow batteries tend to be more cost-effective and durable for large, long-duration stationary energy storage with moderate efficiency, while lithium-ion batteries offer superior efficiency and energy density at lower upfront installation and maintenance costs, favored in smaller-scale and mobile applications. The choice depends heavily on the specific use case, especially discharge duration and scale.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-flow-batteries-compare-to-lithium-ion-batteries-in-terms-of-cost-and-efficiency-2/
