The energy intensity of lithium-ion batteries—defined as the amount of energy required to manufacture them per unit of energy capacity (kWh)—has a significant impact on their overall cost and environmental footprint.
Energy Intensity and Its Cost Implications
- Manufacturing 1 kWh of lithium-ion battery capacity currently requires about 175 kWh of useful energy input, which translates to substantial upfront energy and CO2 emissions (approximately 100 kg CO2 per kWh of battery capacity). For a typical electric vehicle battery pack of 70 kWh, this means 12 MWh of energy expended and around 7 tons of CO2 emitted during production.
- This substantial energy input contributes to the embodied cost within the battery’s price. However, technological advances such as transitioning to a dry manufacturing process for electrodes have the potential to reduce this energy intensity further, thereby lowering production costs.
- The high initial energy and CO2 cost are generally recovered over the battery’s lifecycle, especially when used in electric vehicles which save roughly 10 times more CO2 during operation than was emitted in manufacturing. This lifecycle energy efficiency indirectly affects the economic value proposition of the battery.
Relationship Between Energy Intensity, Energy Density, and Cost
- Improvements in energy density—the amount of energy stored per unit volume or mass—also influence cost. Increasing energy density means more energy capacity in a smaller or lighter battery, which can reduce both materials and production energy intensity per kWh of storage.
- Since lithium-ion batteries have seen a 3.4-fold increase in energy density since 1991 (from about 200 Wh/L to over 700 Wh/L), this improvement has contributed to a substantial drop in the cost per kWh of energy stored.
Cost Trends and Energy Intensity
- Lithium-ion battery pack prices have fallen dramatically, reaching a record low of $139 per kWh in late 2023, a 14% drop recently and roughly 97% decline since commercial introduction in 1991.
- This cost decline is associated with both increased manufacturing scale (learning curve effects leading to roughly 19% price decline per doubling of capacity) and technological advancements that improve energy density and reduce energy intensity.
Summary Table
| Factor | Effect on Cost | Explanation |
|---|---|---|
| High Energy Intensity | Increases upfront manufacturing cost | High energy use increases embodied cost and emissions |
| Reduction in Energy Intensity | Lowers manufacturing cost over time | More efficient processes (e.g., dry electrode processing) reduce energy input needed |
| Increased Energy Density | Lowers cost per kWh stored | More energy in less material reduces cost per unit energy |
| Scale/Manufacturing Learning | Significant cost decreases with production scale | Learning rate ~19% price reduction per doubling of capacity |
In conclusion, the energy intensity of lithium-ion batteries directly affects their manufacturing cost by dictating the amount of energy and materials required per kWh of capacity. Reducing this energy intensity through improved processes and materials enhances cost competitiveness. Coupled with rising energy density and economies of scale, these factors drive down the overall cost of lithium-ion batteries significantly over time.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-energy-intensity-of-lithium-ion-batteries-affect-their-overall-cost/
