How Lithium Prices Influence ESS-Grade LFP Cell Costs

Introduction

How Lithium Prices Influence ESS-Grade LFP Cell Costs Lithium iron phosphate (LiFePO₄ or LFP) is the chemistry of choice for stationary energy storage systems (ESS) thanks to its safety, cycle life, and cost stability.
But battery-grade lithium carbonate (Li₂CO₃) prices can move sharply. The big question: does this heavily impact the final cost of an ESS battery?
The answer: it has a surprisingly small effect — even when prices double.

1. Real-World LFP Cell Examples

Two widely used prismatic LiFePO₄ cells from EVE Energy are great case studies:

  • EVE MB31 – 314 Ah large-format cell (~1 kWh, ~5.6 kg)
  • EVE LF100LA – 100 Ah cell (~0.326 kWh, ~1.98 kg)

Exact lithium content is proprietary, but we can calculate it closely using LiFePO₄’s chemistry.

2. Lithium Carbonate Content in LFP Cells

Lithium makes up about 4.4% of LiFePO₄’s cathode mass, and lithium carbonate is 18.8% lithium by weight.

From this, manufacturing each 1 kWh of LFP storage capacity needs ~0.47 kg of lithium carbonate.

This means:

  • MB31 (≈1 kWh) → ~0.47 kg Li₂CO₃ per cell
  • LF100LA (≈0.326 kWh) → ~0.153 kg Li₂CO₃ per cell

3. Price Change: USD $10,000/t → USD $20,000/t

Let’s compare the impact of lithium carbonate doubling from USD $10/kg to USD $20/kg.

Per cell:

  • MB31 314 Ah:
    • $10/kg → USD $4.70 lithium cost
    • $20/kg → USD $9.40 lithium cost
    • Increase: USD $4.70 (~AUD $7)
  • LF100LA 100 Ah:
    • $10/kg → USD $1.53 lithium cost
    • $20/kg → USD $3.06 lithium cost
    • Increase: USD $1.53 (~AUD $2.30)

4. Effect on a 51.2 V Battery Pack (16 Cells)

Most 51.2 V ESS batteries are built from 16 cells in series:

  • Using MB31 cells (314 Ah / ~1 kWh each):
    • 16 × USD $4.70 increase = USD $75.20 (~AUD $112) more if Li₂CO₃ doubles in price.
  • Using LF100LA cells (100 Ah / ~0.326 kWh each):
    • 16 × USD $1.53 increase = USD $24.48 (~AUD $36) more if Li₂CO₃ doubles in price.

5. Why the Impact Is So Small

Even a 100% jump in lithium carbonate prices adds less than AUD $120 to a large 51.2 V / 314 Ah battery, and under AUD $40 to a smaller 100 Ah version.

That’s because:

  • Lithium carbonate is only a small fraction of the cell’s mass.
  • The rest of the cost comes from iron, phosphorus, graphite, copper, aluminium, electrolyte, casings, BMS, labour, testing, logistics, and installation.

6. Key Takeaways

  • Doubling lithium carbonate from USD $10k/t → USD $20k/t adds:
    • ~USD $75 (~AUD $112) to a large 51.2 V 314 Ah pack
    • ~USD $24.50 (~AUD $36) to a smaller 51.2 V 100 Ah pack
  • Other materials, manufacturing, and installation dominate ESS battery costs.
  • Lithium price swings are important, but they don’t make or break ESS battery affordability.

Sources:

EVE datasheets of 100ah and 314ah cells.

  • Lithium content calculations based on LiFePO₄ molecular composition.