Life Cycle Assessment of Lithium-ion Batteries: A Critical Review

Lithium-ion Batteries

Recent projections suggest that the global production of lithium-ion batteries will skyrocket to 2,857 GWh by 2030. The frequent use of lithium-ion batteries in various systems has necessitated an in-depth understanding of their environmental impacts. 

Life Cycle Assessment (LCA) is a tool that offers a systematic approach to estimating the environmental burdens of a battery’s life cycle.

As per the LCA assessment by Arshad et al., 2022, It is estimated that the production of 1 kWh of lithium-ion batteries capacity results in approximately 150-200 kg of CO2 equivalent emissions.

Further, the extraction of lithium, cobalt, and nickel—key components of lithium-ion batteries—contributes to substantial ecological degradation and resource depletion. 

The manufacturing phase of lithium-ion batteries is particularly energy-intensive; for instance, the cathode production alone accounts for nearly 40% of the total energy consumption. 

Let us now review some existing LCA studies on lithium-ion batteries, highlighting their key findings, methodological approaches, and identified gaps. 

Researches Conducted in Life Cycle Assessment for Lithium-Ion Batteries

Numerous studies have been conducted to understand the impacts of these batteries. Here are some notable research efforts:

1. Application of LCA to Lithium-Ion Batteries in the Automotive Sector

  • Study Overview: This study, conducted by researchers at the University of Salerno, critically reviews the application of LCA to lithium-ion batteries in the automotive sector. 

The authors outline a structured LCA framework, adhering to ISO standards (ISO 14040 and ISO 14044), which includes goal and scope definition, inventory analysis, life cycle impact assessment (LCIA), and interpretation of results.

  • Key Findings: This study explores the application of LCA to evaluate the environmental impacts of these batteries used in electric vehicles. LCA helps identify hotspots in battery production, usage, and disposal, guiding manufacturers toward more sustainable choices. 

The authors discuss practical and methodological aspects of LCA, emphasizing goal and scope definition, inventory analysis, life cycle impact assessment, and interpretation.

By systematically assessing various impact categories, LCA enables stakeholders to reduce the ecological footprint of lithium-ion batteries throughout their life cycle, contributing to the sustainability of electric mobility.

2. In-depth LCA of Lithium-Ion Batteries for Climate Impact Mitigation

  • Study Overview: Researchers from the University of Surrey and Reliagen Holdings Ltd. conducted a rigorous LCA to demonstrate the life cycle environmental impact hotspots of these batteries and ways to improve them.

    The research highlights the significant role of Battery Energy Storage Systems (BESS) in renewable electricity infrastructure, which is essential for mitigating climate change.
  • Key Findings: Key findings include the identification of the lithium-ion cathode as a major global warming potential (GWP) hotspot due to the resource-intensive production of lithium hexafluorophosphate. 

The study quantifies the GWP of these batteries in different scenarios, showing values of 1.7, 6.7, and 8.1 kg CO2-equivalent per kg of battery, depending on the inclusion of recycling credits.

In order to reduce the GWP of BESS, the study suggests several strategies: reducing emissions from material production processes, increasing energy density and lifespan, enhancing recyclability, and utilizing waste resources for battery components. 

These improvements are crucial for making lithium-ion batteries competitive with renewable energy systems.

3. Methodological Approaches to End-of-Life Modelling in LCA Studies

  • Study Overview: This study reviews how the end-of-life (EOL) stage is modeled in LCA studies of lithium-ion batteries. It analyzes 25 peer-reviewed journal and conference papers that consider the whole lithium-ion battery life cycle.
  • Key Findings: The study categorizes the EOL modeling into two main approaches: the cutoff approach (no material recovery, possibly secondary material input) and the EOL recycling approach (material recovery, only primary material input).

It finds that 19 studies follow the EOL recycling approach, while 6 use the cutoff approach. Additionally, some studies employ hybrid approaches, which may lead to double counting of recycling benefits, thus over- or underestimating environmental impacts.

Key findings include the need for well-documented and motivated modeling choices to avoid inaccuracies. The study also notes that 21 of the reviewed studies model hydrometallurgical treatment, while 17 omit waste collection entirely. 

The research highlights  the importance of standardized EOL modeling methods to improve the reliability and comparability of LCA results for lithium-ion batteries.

4. LCA of Lithium-Ion Batteries with Nanoscale Technology

  • Study Overview: Conducted by the U.S. Environmental Protection Agency (EPA), this study assesses the environmental impacts of lithium-ion batteries used in electric and plug-in hybrid electric vehicles, including next-generation technologies involving single-walled carbon nanotubes (SWCNTs).
  • Key Findings: Key findings highlight that the choice of battery chemistry significantly influences environmental impacts, particularly in categories like global warming potential, acidification, and human toxicity. 

For instance, the Li-NCM (Lithium Nickel Cobalt Manganese Oxide) chemistry shows higher potential for toxicity due to the use of cobalt and nickel, compared to chemistries like LiMnO2 (Lithium Manganese Oxide) and LiFePO4 (Lithium Iron Phosphate), which use less toxic metals.

The study emphasizes the importance of the cathode in contributing to upstream and manufacturing impacts, with energy use being a major factor. 

It also notes that solvent-less manufacturing methods can reduce energy consumption and associated environmental impacts.

Advancements in LCA of Lithium-Ion Batteries

The advancements in LCA for these batteries reflect a growing recognition of the need for sustainable practices in technology development. Some of these developments are:

Innovations in Battery Chemistry and Design

Recent innovations in battery chemistry, such as the development of silicon-based anodes and solid-state batteries, have the potential to enhance the performance and sustainability of lithium-ion batteries. 

These advancements not only improve energy density but also reduce reliance on critical materials like cobalt, which has significant environmental and ethical concerns associated with its extraction.

Impact of New Technologies on LCA Outcomes

The introduction of advanced LCA tools and models has improved the accuracy and efficiency of environmental assessments for lithium-ion batteries. 

Tools like SimaPro and GaBi facilitate more comprehensive analyses by allowing for dynamic modeling of various scenarios and technologies. These advancements also open up patent opportunities as companies innovate to meet sustainability goals, leading to a competitive advantage in a market increasingly focused on environmental responsibility.

HiQ-LCA Project

The HiQ-LCA project involves twelve well-known companies and research institutions collaborating to build a high-quality LCA database for batteries. This initiative aims to provide reliable data for companies to determine the carbon footprint of their processes and products.

The project supports companies along the battery value chain in making informed decisions to enhance sustainability and comply with new regulations. As part of the project’s research measurements, the University of Bordeaux, a HiQ-LCA partner, and the CyVi Group first organized a one-day hybrid LCA training in Bordeaux. 

End Note

The life cycle assessment of lithium-ion batteries highlights the need for sustainability improvements across all stages, from material extraction to end-of-life management. Future suggestions include adopting cleaner technologies, enhancing recycling efficiency, and developing alternative materials with lower environmental impacts. 

Advancements in battery chemistry and design, such as silicon-based anodes and solid-state batteries, hold promise for reducing reliance on critical materials like cobalt. As the demand for lithium-ion batteries grows, sustainable innovation must be prioritized to mitigate ecological impacts.