Understand your battery metal emissions

Part 8 of CarbonChain’s ‘High-carbon Commodities’ blog series.

The energy transition demands batteries, and a lot of them — but the metals required to manufacture batteries come with their own environmental and social challenges. 

When most people think about the battery demand associated with the energy transition, they think about EVs (which constitute 80% of battery demand globally). But batteries are essential for other imperative use cases, such as large-scale electricity storage — including storing the power generated by renewable energy sources. 

As the fastest-growing energy technology on the market, batteries are driving a surge in demand for metals like lithium, cobalt, nickel, and manganese. But with this growing demand comes a need for supply chain transparency to address the environmental and social costs of production. And with regulations like the EU Battery Regulation coming into effect, this need has never been more urgent.

In this article, we’ll explore some of the key metals associated with the batteries needed for the energy transition, their environmental impact, and why understanding battery metal supply chains is critical for success in a net-zero economy. 

What metals are used in battery energy storage?

There are a variety of battery technologies in use, though lithium-ion (Li-ion) batteries are the dominant choice for rechargeable batteries today. A lithium-ion battery powers your smartphone, your laptop, and likely your EV, if you drive one. 

Despite the use of these batteries in billions of personal devices the world over, 90% of lithium-ion demand comes from the energy sector. Costs for lithium-ion batteries have fallen dramatically while performance has improved, causing demand from the energy sector to increase ten times over when compared to 2016. The entire Li-ion battery chain, from mining through recycling, could grow by over 30% annually from 2022 to 2030, according to an analysis by the McKinsey Battery Insights team.

Lithium serves as the core of lithium-ion batteries, though not in its metallic state. Manufacturers typically use lithium hydroxide or lithium carbonate because these forms are more stable than lithium metal and safer to handle. In addition to lithium, there are several other metals used in lithium-ion batteries. The specific metals vary, but generally include a mix of cobalt, aluminum, manganese, and nickel.

The carbon footprint of battery metals

Each of the metals associated with the batteries needed for the energy transition comes with its own carbon footprint. To keep things simple, let’s use EV batteries as our example.

The average EV battery cell contains roughly 185kg of metal minerals, excluding materials in the electrolyte, binder, separator, and battery pack casing. 

A battery’s cathode composition determines its capacity and power. Many EV batteries today use nickel-manganese-cobalt (NMC) cathodes, with a breakdown of roughly 60% nickel, 20% cobalt, and 20% manganese.

Each of these metals have unique supply chain challenges. Emission contribution breakdowns can change significantly based on the specific supply chain, which is why decarbonisation pathways should always be evaluated on a case-by-base basis.

Nickel

Though nickel’s contribution to global greenhouse gas (GHG) emissions (roughly 0.27%) is small compared to metals like steel and copper, it will grow with nickel demand, which is expected to increase 65% by the end of this decade. 

CarbonChain’s platform provides comprehensive data on nickel production emissions across more than 101 assets and 22 countries. If you need assistance accurately measuring your nickel emissions, we can help.

Manganese

Manganese demand is also expected to surge — as high as 58 times current levels by 2040 — which means its emissions contribution will increase, too. Manganese’s overall environmental performance, similar to other metals, is closely linked to that of regional grid electricity production. Its use in iron and steel production, which produces 7%–9% of global CO₂e emissions annually, makes it one of the world’s most used metals.

Cobalt

Cobalt’s contribution to global GHG emissions is small (approximately 1.6 million tonnes out of a total 3.4 billion tonnes annually) — but the resource is scarce, and the cobalt mining industry is rife with human rights abuses and linked to excessive environmental degradation. Manufacturers are increasingly seeking alternatives — cobalt is considered the highest material supply chain risk for EVs in the short and medium term.

CarbonChain’s platform has 91.4% coverage of cobalt mined globally and 97.4% coverage of global refined cobalt (cobalt metal and cobalt chemicals). If you need help understanding your supply chain emissions, get in touch.

Manganese, cobalt, and nickel are not the only metals used in lithium-ion battery cathodes. Additional types of Li-ion batteries include lithium-iron-phosphate (LFP), lithium-nickel-cobalt-aluminum-oxide (NCA) and lithium-cobalt-oxide (LCO), among others.

One analysis of published lifecycle assessment (LCA) data shows that material contribution to the carbon footprint of a lithium-ion battery varies by a factor of four, depending on the source and production pathway of materials. 

The median cradle-to-gate carbon footprint of lithium-ion batteries is between 48 and 120 kg CO₂e kWh⁻¹. To put that into context, those numbers would put the carbon footprint of a Tesla Model 3 battery (which holds an 80 kWh lithium-ion battery) between 3,849kg and 9,600kg (9.6 metric tons). Some estimates are even higher.

If no significant measures are taken to reduce upstream emissions, global lithium-ion battery emissions are on track to reach up to 1 Gt CO₂e per year.

What causes battery metal emissions?

The emissions intensity of the metals associated with the batteries needed for the energy transition can vary significantly based on the specific supply chain. Many metals have multiple possible production pathways. 

For example, nickel may go through a ‘mine-smelt-refine’ pathway, or it may undergo high-pressure acid leaching (which is less carbon-intensive than smelting when using laterite ore).

In the case of most metal commodities, the bulk of embedded emissions will stem from the energy required for primary extraction and refining of the raw metal mineral. Emissions intensity will largely depend on how ‘green’ the source of energy is in the particular region in which it’s produced.

Why battery metal emissions vary

Battery metal emissions vary because material contribution — and material production pathways — is not uniform. The carbon footprint of any one battery can vary significantly based on which materials are used, how they’re sourced, and what energy sources are used in manufacturing.

Producing batteries is material-intensive, and comes with high environmental costs. Most lithium is extracted from underground brine reservoirs or hard rock mines. In the case of hard rock mining, 15 tonnes of CO₂e is released into the atmosphere for every tonne of mined lithium. Mining raw materials also requires polluting chemicals and enormous amounts of water. 

And it doesn’t stop there. Heat between 800 and 1,000℃ is required to synthesize the materials needed for battery production. Today, most industries are able to cost effectively reach such high temperatures only through burning fossil fuels.

However, it’s worth acknowledging that despite the not-small environmental footprint associated with battery production, even the ‘dirtiest’ batteries are better than the alternative (which is no batteries at all). Even when powered by coal-generated electricity, EVs still produce fewer emissions over their lifetime compared to gasoline-powered vehicles.

Battery energy storage is a key technology for the energy transition — it’s unlikely we can transition away from fossil fuels without them.

New and emerging battery technologies

But there is an upside. Now, more than ever, the race is on to improve upon current battery technologies and find cleaner ways to manufacture materials. 

Sodium-ion batteries, as one example, could be a more resource-efficient alternative to lithium-ion batteries. They rely on more abundant and lower-cost materials and reduce pressure on critical minerals like lithium and cobalt. Such batteries show promise for large-scale energy storage and some vehicle applications.

Solid-state batteries promise higher energy density and safety, potentially altering the types and quantities of materials required for production. One study found that solid-state batteries could reduce the carbon footprint of an EV battery by 39%.

While these technologies are still in their early stages, their adoption could significantly impact the demand for traditional battery metals and the emissions associated with their extraction and processing. 

Calculate your battery metal emissions

Understanding the emissions associated with your battery metals requires understanding the specific supply chain of each material contribution.

The new EU Battery Regulation, which requires manufacturers to carry out conformity assessments and provides extended general labeling and information requirements, is making it more important than ever to understand the emissions factors affecting your end products at each step of production. 

CarbonChain’s carbon accounting platform has the granularity of data you need. If you need help understanding the product lifecycle stages of your commodity, we can help.

CarbonChain provides accurate, asset-level carbon accounting for your battery supply chain, from the mine to the manufactured product. Compare emissions between assets and find lower-carbon options on our platform, while sharing the results and progress with your stakeholders.