Battery costs and especially battery prices have been declining steadily for years at a rate that no one had predicted and that is more drastic than experts had expected. Experts have long been in agreement that the strong expansion of capacities, for example in China, will lead to an excess of capacity and therefore will contribute to further price erosions.
At odds with this trend is the observation that the prices for electrolytes, which make up about 10 % of cell costs, are rising significantly. What is causing the prices for electrolytes to increase and is this an indication that there will be a pause in the downward trend in battery cell prices in general?
Liquid electrolytes are currently most often used in lithium-ion batteries. These contain a mixture of the following components:
- Electrolyte solvent (often a mixture of two to three organic carbonates)
- Electrolyte salt (primarily LiPF6)
- Electrolyte additive (often a “grab bag” of three to ten “magic ingredients”)
The electrolyte solvents are generally linear or cyclical carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), ethylene carbonate (EC) and many more. These are largely industrial chemicals that are produced, besides their use as battery electrolytes, for a number of applications in the production of intermediate products and polymers, known as commodities. For use in batteries, a small amount “only” has to be purified. The price for this electrolyte solvent has remained stable or had a slightly downward tendency.
It’s a very different picture for electrolyte additives, which on the one hand are only used in small amounts as high-performance special chemicals but on the other hand already account for more than 20 % of the cost of electrolytes, with an upward tendency.
The cost of the salt lithium hexafluorophosphate (LiPF6) is tied to the prices of LCE (lithium carbonate equivalent), which has increased by almost 500 % in the last ten years and is currently at an all-time high. This price increase is having a strong effect on finished electrolytes and cathode materials.