Introduction

Against the dangers of climate change, batteries power our clean energy dreams. But at the same time, they come with a hidden environmental cost. It’s time to address this before it undermines our progress.

For instance, it is estimated that each kilowatt-hour (kWh) of batteries produced generates between 150 to 200 kilograms of CO₂. 

Furthermore, the production of batteries for electric vehicles (EVs) alone is projected to result in the mining of over 10 million tons of lithium, cobalt, nickel, and manganese between 2021 and 2030.

The lifetime of a battery, defined as the total number of charge/discharge cycles it can undergo before losing capacity or failing, also contributes to battery environmental impact. 

Typically, a battery’s lifespan ends when its capacity reaches 80% of its initial maximum capacity.

As a result, understanding this aspect is important as it directly influences the frequency of battery replacement and, consequently, the battery environmental impact.

Environmental Impact of Batteries: A Brief Overview

Batteries are essential for storing clean energy, yet their production carries a significant environmental cost.  Here’s a breakdown of the key factors:

• Dependence on Fossil Fuel: 50-70% of the world’s electricity still comes from fossil fuels like coal and gas. This high-carbon energy source powers battery manufacturing, resulting in substantial CO2 emissions during production.
• Global Impact: Battery manufacturing is emissions-intensive, with China (45%), Australia (9%), and Indonesia (13%) currently the top contributors. However, the expected shift towards cleaner energy sources could reduce emissions by up to 38% by 2050.
• Material Sourcing: Mining the raw materials for batteries, such as lithium, cobalt, and nickel, has its own environmental impact. For example, due to limited domestic lithium resources, India relies heavily on battery imports from China.
• Emissions Comparison: A 2021 study found that the production process itself accounts for 46% of total carbon emissions associated with Electric Vehicles (EVs). This underscores the need for cleaner manufacturing practices.
  

As a result, it’s vital to address the battery environmental impact during production. This involves shifting towards renewable energy sources for manufacturing, ensuring responsible material sourcing, and investing in efficient battery recycling and reuse systems.

Minimizing Environmental Impact of Batteries: Existing Research

Some of the existing research that minimizes the battery environmental impact are:

1. Efficient Lithium-Ion Batteries Recycling

A study by Xiaolu Yu et al. 2022, discussed the urgent need for lithium-ion battery (LIB) recycling due to the rapid growth of the electric vehicle (EV) industry. The study established a multilevel index evaluation system based on environmental battery characteristics and developed the life cycle assessment method and the entropy weight approach to evaluate environmental load. 

Key Findings:

• Battery Performance:   Li-B batteries were found to have the least environmental impact during their usage phase. 
• Regional Differences: China’s current power structure results in a notably higher carbon footprint and other environmental impacts, including ecological footprint, acidification potential, eutrophication potential, and human toxicity – carcinogenic and non-carcinogenic.
• The Path to Improvement: The study concluded that although the current power structure in China could be more conducive to the sustainable development of EVs, the optimization of the power structure is expected to allow electric vehicles to achieve clean driving in China.

2. Environmental Impact Assessment of Battery Boxes 

A 2024 study by Xinyu Li et al. investigated the environmental benefits of replacing traditional steel battery boxes with lightweight alternatives.  Using GaBi software for life cycle modeling and the CML2001 method for assessment, the researchers found significant advantages for lightweight options.

Key Findings:

• Reduced Impact: Overall, lightweight materials demonstrated a reduced environmental impact compared to conventional steel boxes.
• Top Performers: Carbon fiber sheet molding compound (CF-SMC) and aluminum alloy boxes showed the most notable reductions in environmental effects.
• Practical Considerations: While composite materials offer great potential, aluminum alloy remains an excellent choice for minimizing the life cycle environmental impact of battery boxes, especially where widespread recycling for composites is not yet available.

3. Estimating the Environmental Impacts of Global Lithium-Ion Battery Supply Chain:

This study examined the energy use and greenhouse gas emissions of both current and potential future battery technologies, specifically those using nickel-manganese-cobalt (NMC) and lithium-iron-phosphate (LFP) chemistries.  

The analysis considered the entire supply chain and predicted the effects of decarbonizing the electrical grid in relevant countries.

Key Finding:

• The Potential of LFP: The study revealed that transitioning to LFP-based battery chemistry could result in significant emission reductions, estimated at approximately 1.5 GtCO2eq (gigatons of carbon dioxide equivalent).

Reducing Battery Environmental Impact: Techniques and Technologies

Some of the techniques that can help reduce the battery environmental impact include the following:

1. Lithium-Ion Battery Recycling Techniques: 

A study published in ACS Energy Letters discussed the urgent need for lithium-ion battery (LIB) recycling due to the rapid growth of the EV industry. It discussed three main recycling techniques for lithium-ion batteries: direct recycling, pyrometallurgy, and hydrometallurgy. 

1. Direct recycling: It involves disassembling the battery and reusing the cathode material. 
2. Pyrometallurgy: This uses high temperatures to convert the battery’s metal oxides into metal or metal compounds. 
3. Hydrometallurgy: It relies on aqueous solutions to dissolve the battery’s components. 

With a reduction in greenhouse gas emissions of 61, 51, and 17%, respectively, hydrometallurgical and pyrometallurgical processes are next in line with direct recycling, which has the least battery environmental impact. 

2. Battery Innovation in Clean Energy Transition: 

A collaborative study by the International Energy Agency and the European Patent Office analyzed the surge in battery-related patents filed since 2000.  With over 65,000 international patent families examined, the key findings reveal:

• Rapid Growth: Between 2005 and 2018, the average annual growth rate in battery and power storage patents was 14% – four times higher than the average across all technology fields.
• Battery Dominance: Nearly 90% of patents in electricity storage are directly related to batteries.
• Driving Force: Advances in rechargeable lithium-ion batteries, widely used in consumer electronics and electric vehicles, are the primary catalyst for this innovation boom.

3. Battery Recycling Technologies: 

The study discussed various recycling techniques, including the following:

• Mechanical preprocessing involves shredding and sieving to facilitate the separation and sorting of battery components.
• Magnetic separation and density separation are used to target specific materials further.
• Biohydrometallurgy uses microbes to extract metals in a cleaner and more targeted way.
• Electrochemical methods are also becoming increasingly important for separations.

4. Sustainability of Technologies to Recycle Spent Lithium-Ion Batteries: 

This paper discussed the sustainability of 33 different technologies for LIBs recovery, even if developed only at the laboratory level. These technologies, some still at the laboratory level, were evaluated using a preliminary screening approach to Life Cycle Analysis (LCA). 

The evaluation tool used was ESCAPE (Evaluation of Sustainability of Material Substitute using Carbon Footprint by a Simplified Approach), which calculated embodied energy and carbon footprint. 

The ESCAPE analysis results showed that the sustainability of these technologies was affected by parameters such as thermal and mechanical treatments and chemicals and water use. 

Final Note

Addressing the battery environmental impact is paramount for sustainable energy transitions. Research efforts like efficient lithium-ion battery recycling, lightweight material substitution in battery boxes, and advancements in battery chemistry contribute to mitigating environmental burdens. 

Patents related to lithium-ion battery recycling techniques and innovations in clean energy storage underscore a global commitment to eco-friendly solutions. These studies can inform global and regional clean energy strategies to boost technology innovations, decarbonize the electricity grid, and optimize the global supply chain toward a net-zero future.