Researchers at Argonne National Laboratory have conducted life cycle analyses (LCAs) for battery-grade lithium carbonate (Li₂CO₃) and lithium hydroxide monohydrate (LiOH•H₂O) produced from Chilean brines (Salar de Atacama) and Australian spodumene ores. An open-access paper on the study is published in the journal Resources, Conservation and Recycling.

The team also extended the LCA beyond the production of Li₂CO₃ and LiOH•H₂O to include battery cathode materials as well as full automotive traction batteries to observe the effect that the lithium production pathways had on these end products.

The LCA covers material, water, and energy flows associated with lithium acquisition; lithium concentration; production of lithium chemicals, battery cathode powders, and batteries; and associated transportation activities along the supply chain.

The researchers found that, based on battery cathode material, the difference in lithium source represents a difference of up to 20% for NMC811 cathode greenhouse gases (GHGs) and up to 45% for NMC622 cathode GHGs.

For full batteries, this represents a difference of up to 9% for NMC811 batteries and 20% for NMC622 batteries.

Cradle-to-gate life cycle GHG results for batteries by input and process with lithium from different sources. Kelly et al.

• Production of Li₂CO₃ from brine-based resources had less life cycle GHG emissions and freshwater consumption per tonne of Li₂CO₃ than Li₂CO₃ from ore-based resources.

• LiOH•H₂O produced from brine-based lithium also had less life cycle GHG emissions and freshwater consumption per tonne of LiOH•H₂O than LiOH•H₂O from ore-based resources.

The results show that concentrated lithium brine and its related end products can vary significantly in energy consumption, greenhouse gas emissions, sulfur dioxide emissions and water consumption depending upon the resource allocation method used.

This study establishes a baseline for current practices and shows us potential areas for improvement. With further research, it will be possible to use this information to help develop best practices for producing lithium in the most sustainable way.

—Argonne lifecycle analyst and lead author Jarod Kelly

In the study, the researchers used operational data supplied by SQM, one of the world’s leading producers of lithium. SQM initially approached Argonne last year about a collaboration in support of ambitious sustainability targets the company recently unveiled.

According to our sustainability plan, we want to look more closely at carbon emissions, water consumption and energy consumption in our lithium products, and see how it affects the rest of the value chain. This information will help us achieve our goal of being carbon neutral by 2030.

—Veronica Gautier, SQM’s head of innovation

The analysis will also help address an overarching question in the global trend toward the electrification of transportation with battery electric vehicles, said Michael Wang, director of the Systems Assessment Center at Argonne and a study co-author.

Often electrification is for the purpose of pursuing environmental sustainability. But we need to know more about lithium battery production before we can say we are truly on a sustainable path. This study provides crucial insights into the electric mobility value chain.

—Michael Wang

The formal analysis used Argonne’s open-source modeling tool, GREET (Greenhouse gases Regulated Emissions and Energy in Technologies), with detailed data and technical insight coming from SQM. In addition to the brine-based lithium extracted in Chile, the researchers augmented their data by modeling ore-based lithium extracted from spodumene ore in Western Australia.

Resources

• Jarod C. Kelly, Michael Wang, Qiang Dai, Olumide Winjobi (2021) “Energy, greenhouse gas, and water life cycle analysis of lithium carbonate and lithium hydroxide monohydrate from brine and ore resources and their use in lithium ion battery cathodes and lithium ion batteries,” Resources, Conservation and Recycling, Volume 174 doi: 10.1016/j.resconrec.2021.105762