The Life Cycle Energy Consumption and Greenhouse Gas Emissions from Lithium-Ion Batteries

This report presents the findings from the Swedish Energy Agency and the Swedish Transport Administration commissioned study on the Life Cycle energy consumption and greenhouse gas emissions from lithium-ion batteries. It does not include the use phase of the batteries.

Summary

The study consists of a review of available life cycle assessments on lithium-ion batteries for light-duty vehicles, and the results from the review are used to draw conclusions on how the production stage impacts the greenhouse gas emissions. The report also focuses on the emissions from each individual stage of the battery production, including; mining, material refining, refining to battery grade, and assembly of components and battery.

The report is largely structured based on a number of questions. The questions are divided in two parts, one focusing on short-term questions and the second on more long-term questions. To sum up the results of this review of life cycle assessments of lithium-ion batteries we used the questions as base.

Part 1 – Review the iteratively specified chemistries and answer the following short-term questions related to the battery production: How large are the energy use and greenhouse emissions related to the production of lithium-ion batteries? How large are the greenhouse gas emissions related to different production steps including mining, processing and assembly/manufacturing? What differences are there in greenhouse gas emissions between different production locations? Do emissions scale with the battery weight and kWh in a linear or non-linear fashion?

Part 2 – To answer more long-term questions related to opportunities to reduce the energy use and greenhouse gas emissions from battery production. a) What opportunities exist to improve the emissions from the current lithium-ion battery chemistries by means of novel production methods? b) What demands are placed on vehicle recycling today? c) How many of the lithium-ion batteries are recycled today and in what way? d) What materials are economically and technically recoverable from the batteries today? e) What recycling techniques are being developed today and what potential do they have to reduce greenhouse gas emissions? f) How much of the production emissions can be allocated to the vehicle?

Based on the assessment of the posed questions, our conclusions are that the currently available data are usually not transparent enough to draw detailed conclusions about the battery’s production emissions. There is, regardless, a good indication of the total emissions from the production, but this should be viewed in light of there being a small number of electric vehicles being produced compared to the total number of vehicles. The potential effects of scale up are not included in the assessments. Primary data for production, especially production of different pack sizes, is therefore interesting for future work.

This report also concludes that there is no fixed answer to the question of the battery’s environmental impact. There is great potential to influence the future impact by legislative actions, especially in the area of recycling. Today there is no economic incentive for recycling of lithium-ion batteries, but by placing the correct requirements on the end of life handling we can create this incentive. Coupling this type of actions with support for technology development both in battery production processes and battery recycling can ensure a sustainable electric vehicle fleet.

The review of the available life cycle assessments also highlighted that there is a need for improving the primary data used in the studies, as there is little new data being presented. Additionally, the studies are often not transparent in their data choices and modelling assumptions, leading to a situation where comparing results becomes very difficult. Regardless of this, the review found a number of critical factors for determining differences in the results. The assumptions regarding manufacturing were shown to have the greatest variation and impact on the total result. In order to improve our understanding of the environmental impact of the battery production we need more than LCA results. We need more clear technical descriptions of each production step and where they are performed so that the emissions found in the reviewed life cycles assessments can be defined into different stages. Not until we have a clear definition of stages can we assess where the energy consumption and emissions are largest, or what actions that can help lower the impact.

Coworkers: Mia Romare, Lisbeth Dahllöf

Year: 2017.0

Report number: C243

Authors: Mia Romare, Lisbeth Dahllöf

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