This article is contributed by Ascend Elements’ Chris Duhayon, Head of Non-Cathode R&D, Adrian Garaycochea, Life Cycle Assessment Analyst, and Emma Giddings, Life Cycle Assessment Analyst
The Energy – Material Nexus
Since the Industrial Revolution, human activities have dramatically increased greenhouse gases (GHG), destabilizing the global climate in a relatively short period of time. In fact, NASA has recently confirmed that 2023 was the warmest year on record1. A vast body of scientific literature demonstrates the disastrous effects of the current climate crisis2–5, which is an intersectional issue that poses synergistic threats not only to our economic system but to our very existence6.
The good news is that we, as a global species, have been able to come together and cooperate for a common mission: achieving net-zero GHG emissions by 2050. This global agreement, known as the Paris Agreement, has driven 196 countries, including the U.S., and a plethora of companies to increasingly announce pledges to reduce their emissions7.
Against this backdrop, the transport sector plays a critical role in meeting global climate targets, as it alone accounts for about one-third of the total U.S. GHG emissions8. Significant policy interventions, such as the Inflation Reduction Act (IRA), have driven the uptake of clean technologies and the phase-out of carbon-intensive ones. For example, incentives are provided to replace internal combustion engine (ICE) vehicles with electric vehicles (EVs) for consumers and U.S. automakers9. This has been reflected in U.S. EV sales, which increased by 50% in 2023 compared to 2022, with the trend continuing upward10. Yet, the deployment of EVs translates into a natural resources issue, more specifically, critical materials. On average, an EV uses eight times more critical materials than an ICE vehicle11.
Limiting global warming to achieve a net-zero GHG emissions scenario will lead to a rapid and massive increase in the demand for critical materials. According to a recent report from the International Energy Agency (IEA), the demand for nickel, cobalt, and lithium will increase sevenfold, fourfold, and thirteenfold, respectively, by 204012.
This imminent demand for key materials underscores the fact that energy security depends on lithium, nickel, and other EV metals13. Furthermore, it highlights the nexus between the materials necessary for the clean energy transition and their extraction through mining activities, which are fraught with significant risks and constraints, including reserve locations, export quotas, environmental impacts, geopolitical volatility, and technical capabilities14.
For example, Indonesia holds the world’s largest supply of nickel (a key metal that boosts an EV’s battery energy density) and has passed to block exports to build its own EV industry15. In addition, the only nickel mine in the United States is expected to be depleted by 2025, and the country lacks a nickel refinery13. Similarly, China threatened in 2019 to block exports to the U.S. of rare earths16, which are used to make the magnets that help turn power from an EV battery into motion. Regarding cobalt, a key material needed to prevent EV battery erosion, it is mostly mined in the Democratic Republic of the Congo (DRC), which holds more than half of the world’s cobalt supplies17. However, child labor is often used to extract minerals there18, a source of significant concern for automakers, regulators, and policymakers13.
Under these conditions, mining and refining critical materials are the limiting factors in accelerating the transition to a clean global energy system12,13,19. Indeed, mining is necessary for green energy, yet it does not have the best reputation. Recent incidents back up the criticism, ranging from the destruction of a 46-thousand-year-old Aboriginal rock shelter in Western Australia in 202020 to a fatal tailing dam collapse in Brazil that killed nearly three hundred people in 201921.
Automakers are recognizing that their future lies in EVs, although they understand that the supply chain for these vehicles must be low-carbon and free from human rights abuses and toxic pollution13. In this context, it is imperative to capture existing and upcoming critical materials from scrap manufacturers and spent EV batteries to combat climate change in the short and long term.
The Conventional Approach to Primary Cathode Material: Mining
One option to meet the growing demand for battery materials is primary extraction through mining. The process of mining to produce Cathode Active Material (CAM) involves extracting raw materials, typically nickel, manganese, cobalt, lithium, and graphite, from the earth. These materials are then refined and purified to be used in cathode and anode active battery materials22.
Nickel is a crucial component in the production of high-performance batteries, as it increases the energy density of the battery cells23. Today, nearly half of the total global nickel production is from Indonesia24, and this share is expected to grow to 75% by 203025. This growth is driven by significant investments in mining and refining infrastructure, positioning Indonesia as a dominant player in the global battery industry26.
The Traditional Way of Recycling: Hydrometallurgy
Hydrometallurgical processes have been applied to battery recycling since the 1980s. The recycling rate of the lead-acid batteries originating from the automotive industry was as high as 99% in the U.S. in 2023, and the U.S. lead battery manufacturer source approximately 83% of the needed lead from North American recycling facilities27. A combination of pyrometallurgical and hydrometallurgical approaches have been used for that purpose, which usually implies starting with sorting the batteries according to their type. Each type of battery has its own recycling process, and for example, alkaline batteries cannot go through the process dedicated to the lead-acid batteries. The process would then usually continue with the operation of crushing and separating the components. The plastics would be recovered, and the lead-based material would be processed by a pyrometallurgical method, such as smelting. The sulfuric acid would be neutralized or treated to produce coproducts.
The development of the recycling processes for lithium-ion batteries has followed the adoption of these batteries for major applications, such as EVs, and is in the process of reaching technological maturity. The feed material is currently mainly off-spec material and manufacturing scrap and is expected to progressively shift towards end-of-life batteries28. Pyrometallurgical or hydrometallurgical approaches (or a combination of the two) were developed for the recycling of lithium-ion batteries, and they initially followed the same principles as the other types of batteries. The lithium-ion batteries are more complex and engineered than lead-acid batteries. They contain a cathode, an anode, separator material, an electrolyte, and current collector materials. The cathode is the active material of the battery, and can consist of lithium iron phosphate, or lithium nickel-manganese-cobalt oxides. The anode is usually graphite, and the separator material is a polymer material. The current collector material is usually aluminum for the cathode and copper for the anode.
The materials to be recycled need to be crushed into smaller particles, and then sorted according to certain physical parameters, such as size or density. This allows to sort out most of the plastics, aluminum and copper, which can be further recycled and refined in their dedicated recycling sector. The remaining mixture is commonly called “black mass” or “black sand”, mostly contains the cathode and the anode materials, and requires further processing. The approach of classical hydrometallurgy is to process these materials to produce single and refined products, such as individual metal salts. This can be manganese sulfate, cobalt sulfate, nickel sulfate, and lithium hydroxide or carbonate. This approach is usually very process intensive and requires up to 18 operations to be successful. The black mass would be leached (made to react with a water-based solution containing reagents such as sulfuric acid and hydrogen peroxide) to put the metals of interest in solution. The remaining solids are filtered out, and the solution undergoes a complex process of impurity removal, combined with the separation and concentration of the single metals or their salts, to eventually produce the solid form of the metal salts. These steps may include mixing, heating, separating, filtering, crystallizing and drying. The products of classical hydrometallurgy might require further refining or pre-processing to be fit for the use in the production of new precursor cathode active material. This usually implies a higher reagent and energy consumption, a larger plant footprint, and eventually a higher carbon footprint.
Ascend Elements’ patented Hydro-to-Cathode® process differs from classical hydrometallurgical processes as it does not involve the production by isolation of the single metals or their salts, but maintains the metals of interest (nickel, manganese and cobalt) in solution, and drives out the impurities by different means. The obtained solution is fit for direct precursor synthesis. This is characterized by a shorter and more efficient recycling loop.
Ascend Elements’ HtC
Ascend Elements’ Hydro-to-Cathode® process is an innovative method that converts a mixed stream of used lithium-ion batteries and manufacturing scrap into high-purity, battery-grade cathode active material. This approach maximizes the value of recycled materials while reducing costs and carbon emissions. Despite concerns within the automotive industry about the performance of recycled battery materials, several peer-reviewed studies have shown that Ascend Elements’ engineered battery materials perform just as well as those made from primary (or mined) sources29.
Process Overview
The Hydro-to-Cathode® process selectively leaches out impurities rather than valuable metals, which allows for more efficient recovery and processing. The process can be broken down into the following steps:
- Shredding:
- Shredding: Spent lithium-ion batteries and manufacturing scrap undergo an industrial shredding process, which reduces the size of the materials and facilitates the separation of different components.
- Separation: Through a sorting process, the shredded materials are separated into black mass and other components such as plastic, copper, and aluminum. The black mass continues to the next processing step while the separated co-products (plastic, copper, and aluminum materials) are sold.
- Black Mass Leaching & Filtration:
- Lithium Extraction: The lithium is extracted using a recycled process solution, which is then precipitated, filtered, and dried, producing tech-grade lithium carbonate that is sold to customers. The filtrate from this process is then recycled back into the lithium extraction process.
- Leaching & Impurity Removal: The black mass undergoes a chemical leaching phase where the nickel, cobalt, and manganese are dissolved into the solution. The impurities are then removed, ensuring that the valuable metals remain in the solution.
- Anode Material Separation: The remaining solid graphite material is separated from the solution and sold.
- NMC Ratio Adjustment:
- Solution Adjustment: The dissolved metal solution is adjusted to achieve the desired metal sulfate composition. This adjustment depends on the specific chemistry of the feedstock and the requirements of the final product.
- Solution Adjustment: The dissolved metal solution is adjusted to achieve the desired metal sulfate composition. This adjustment depends on the specific chemistry of the feedstock and the requirements of the final product.
- Co-precipitation:
- Direct Precursor Synthesis: The adjusted metal solution undergoes direct precursor synthesis, resulting in the formation of precursor cathode active material (pCAM). This intermediate product can either be sold directly to customers or undergo a calcination process to produce Cathode Active Material (CAM).
- Direct Precursor Synthesis: The adjusted metal solution undergoes direct precursor synthesis, resulting in the formation of precursor cathode active material (pCAM). This intermediate product can either be sold directly to customers or undergo a calcination process to produce Cathode Active Material (CAM).
- Wastewater Processing:
- Waste Repurposing: The wastewater stream from pCAM synthesis, which contains sodium sulfate and residual lithium, is processed to extract valuable materials:
- The sodium sulfate is repurposed, effectively eliminating this as a waste stream.
- Residual lithium in the wastewater is extracted through another precipitation and filtration process, producing additional lithium carbonate for sale.
- Waste Repurposing: The wastewater stream from pCAM synthesis, which contains sodium sulfate and residual lithium, is processed to extract valuable materials:
By implementing the Hydro-to-Cathode® process, Ascend Elements provides an environmentally responsible solution for the recovery of critical materials from end-of-life batteries and manufacturing scrap. This recycling process also reduces waste generation by recycling water and reagents wherever possible and turns potential waste outputs into valuable resources.
Comparing Environmental Impacts
How do the impacts of the Hydro-to-Cathode® process compare to other CAM production processes?
Across the manufacturing industry, there is a growing need for conscious decision-making to decrease environmental impacts and enhance sustainability. To make these decisions, understanding the full environmental impact of a product or service is essential – this is where Life Cycle Assessment (LCA) comes in.
Life Cycle Assessment Framework
LCA is a methodology that provides a holistic understanding of the potential environmental impacts of a product, process, or service by analyzing its entire life cycle. It considers:
- Materials: Identifying and quantifying materials utilized throughout the process
- Transportation: Evaluating the method of transportation and the distances materials and final products travel to and from the production site
- Energy Consumption: Measuring the amount of energy required by the process, and determining the energy source
- Waste & emissions: Assessing the types and quantities of wastes and emissions generated
This framework is integral to Ascend Elements’ R&D, enabling them to anticipate environmental impacts before they occur. This foresight is crucial for making informed decisions about process design and selecting the most sustainable options.
Using LCA methodology, Ascend Elements has evaluated the environmental impacts of its patented Hydro-to-Cathode® process for producing NMC 622 CAM30. This assessment includes every stage from the shipment of the spent batteries to their facility, through the CAM production process, and finally, the transportation of the finished CAM to a designated location. This evaluation was performed by Minviro in accordance with the ISO 14067 standard and has been critically reviewed by a panel of experts.
This evaluation not only analyzed the overall environmental footprint, but also identified critical “hotspots” which are specific areas that emit higher levels of CO2e within the process. By focusing on these hotspots, Ascend Elements has formulated three key decarbonization scenarios aimed at reducing the CO2e footprint by 80% by 2030:
- Use of 100% renewable energy in recycling and manufacturing facilities
- Use of rail to transport materials
- Use of responsibly sourced lithium carbonate (Li2CO3).
Results
When using nickel sourced from Indonesia, traditional mining processes generate approximately 42.8kg CO2e for every 1 kg of NMC 622 CAM. With Ascend Elements’ current Hydro-to-Cathode® process available in 2024, manufacturing 1 kg of NMC 622 cathode generates 21.9 kg of carbon emissions. Ascend Elements’ process naturally delivers significant reductions in carbon emissions – approximately 49% lower compared to producing primary materials from mining using Indonesian Nickel.
By implementing the three key decarbonization scenarios, the 2030 carbon footprint of CAM production using the Hydro-to-Cathode® process is estimated to generate 4.4 kg CO2e for every 1kg CAM which is a 90% reduction in CO2e emissions compared to CAM production from mining, as shown in the figure below.
To put the climate impact in perspective, the carbon emissions reduction from the 2030 Hydro-to-Cathode® process can be compared to taking a certain number of internal combustion engine (ICE) vehicles off the road for one year31. If Ascend Elements manufactures 10,000 metric tons of NMC 622 (or material for about 125,000 EVs), the emissions reductions are substantial – compared to primary material from mining, it is equivalent to taking 83,478 ICE vehicles off the road for a year.
Looking at the lifetime emissions of an ICE vehicle vs. EV, an EV produced using Ascend Elements’ (AE) CAM needs to travel only 17,700 miles before its total CO2e emissions are lower than those of an ICE vehicle. Assuming an annual mileage of 15,000 miles per year32, this breakeven point can be achieved in just 1 year and 2 months. Furthermore, with the adoption of decarbonization strategies within the process, an EV equipped with their low-carbon CAM needs to travel only 12,000 miles before its emissions are lower than those of an ICE vehicle, which can be achieved in only 10 months of driving.
The figure below illustrates these findings, comparing the cumulative CO2e emissions of ICE vehicles with those of EVs using both standard and decarbonized CAM from Ascend Elements.
These findings demonstrate the potential of Ascend Elements’ Hydro-to-Cathode® process to significantly reduce GHG emissions within the EV supply chain and the transportation industry, contributing to low-carbon and sustainable manufacturing practices for Ascend Elements and its partners.
Moving Forward to Net Zero
Cutting global GHG emissions requires a global transition to clean energy, which in turn involves a massive demand for critical materials. This places significant pressure on extracting minerals from the earth’s crust, often associated with negative externalities for the environment and local communities, while also risking domestic energy security33.
To mitigate the mining burden, the way forward is to recycle critical materials from spent LIBs. This also diverts lithium-ion batteries disposal into landfills, preventing environmental and health threats from heavy metals and toxic hazards34. Thus, recycling not only saves natural resources but also prevents pollution from toxic components. However, some traditional recycling methods are carbon-intense processes35, something that must be addressed to truly achieve net zero emissions.
In this context, Ascend Elements captures critical materials from spent lithium-ion batteries and gigafactory scrap to manufacture engineered battery materials through its patented method, Hydro-to-Cathode®. This method is known for its ultra-efficient EV battery recycling process, recovering up to 98% of critical battery materials and producing CAM with up to 49% lower GHG emissions compared to traditional production methods today30. Moreover, Ascend Elements has recently committed to the Science-Based Targets Initiative (SBTi) to further reduce its GHG emissions and achieve net zero before 205036. This commitment aligns with the latest climate science and aims to meet the goals of the Paris Agreement.
Ascend Elements outlines its decarbonization pathways to meet the SBTi commitment by applying a LCA approach. This simple yet powerful framework provides insights from a systems perspective, avoiding the oversight of unintended consequences and identifying leverage points to reduce environmental impacts across the value chain. As a result, Ascend Elements has integrated LCA approaches into its core strategy. This ultimately results in end-products downstream with lower GHG emissions, which is particularly relevant to EV Original Equipment Manufacturers (OEMs) in addressing their scope 3 emissions, allowing them to meet their own climate targets and accelerate the global transition to net zero carbon emissions.
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