The energy used to make a battery is an interesting topic as the whole premise is that it is a “green” product.
Yuan et al [1] looked at the LMO/Graphite based 24kWh pack in the Nissan Leaf and came to a total energy requirement per kWh of cell capacity of 679kWh/kWh. These energy figures are based on a pilot line scale and hence are high.
This also gave an interesting breakdown of the energy required for each step in the process. The highest energy use is in the drying and solvent recovery and the energy required to operate the dry room.
Romare and Dahllöf [3] conclude with a larger number and bigger range for cell manufacturing energy requirement of 97 to 180kWh/kWh.
Simon Davidsson Kurland [2] has summarised a number of studies and looks at the Northvolt and Tesla Gigafactories to get a range of 50 to 65kWh/kWh. This is the first reference to look at the energy use of the large cell manufacturing plants, good data points as this scale of plant dominates the cell manufacturing landscape.
Jinasena et al [4] give an in-depth breakdown of the studies that have been done to date, from this they build a model and present some interesting data. They conclude that the energy required to make a variety of chemistries is 47.23 ± 13.03 kWh/kWh for a 2GWh plant.
The breakdown shows that anode drying, cathode drying and the dry room account for 96% of the overall energy use.
They also show little variation based on cell chemistry, except the LTO based anode cells that require NMP to be used in the anode process and hence brings the anode energy requirement up to that of the normal cathodes.
The cell manufacturing process requires ~50kWh/kWh when produced at GWh/year scale.
Note: this number does not include the energy required to mine, refine or process the raw materials before they go into the cell manufacturing plant.
References
- Yuan, Chris, Deng, Yelin, Li, Tonghui, and Yang, Fan. Manufacturing energy analysis of lithium ion battery pack for electric vehicles. United Kingdom: N. p., 2017.
- Simon Davidsson Kurland, Energy use for GWh-scale lithium-ion battery production, Environmental Research Communications
- Mia Romare, Lisbeth Dahllöf, The Life Cycle Energy Consumption and Greenhouse Gas Emissions from Lithium-Ion Batteries, IVL Swedish Environmental Research Institute 2017
- Jinasena, A.; Burheim, O.S.; Strømman, A.H., A Flexible Model for Benchmarking the Energy Usage of Automotive Lithium-Ion Battery Cell Manufacturing. Batteries 2021, 7, 14
Cell Manufacturing Process
In order to engineer a battery pack it is important to understand the fundamental building blocks, including the battery cell manufacturing process. This will allow you to understand some of the limitations of the cells and differences between batches of cells. Or at least understand where these may arise.