Lithium (Li) and nickel (Ni) are two key raw materials for batteries, and their production processes can have very different emission profiles. This chart from Wood Mackenzie shows how nickel and lithium mining can have a significant impact on the environment, depending on the extraction process. Nickel emissions per extraction process Nickel is a key metal in modern infrastructure and technology, primarily used in stainless steel and alloys. Nickel's electrical conductivity also makes it ideal for facilitating the flow of electricity within batteries. Today, there are two main methods of nickel extraction: laterite deposits, which are mainly found in tropical regions. This involves open-pit mining and requires the removal of large amounts of soil and overburden to obtain nickel-rich ores. From sulphide ores, including nickel-bearing sulphide minerals from underground or open-pit mining deposits. While nickel laterites account for 70 per cent of the world's nickel reserves, magmatic sulphide deposits have produced 60 per cent of the world's nickel reserves over the past 60 years. Sulphide mining typically emits less carbon dioxide per tonne of nickel equivalent than laterite mining because it causes less soil disturbance and has a smaller physical footprint.

Extraction of nickel from laterite can have significant environmental impacts such as deforestation, habitat destruction and soil erosion. In addition, laterite ores typically contain high levels of moisture and require energy-intensive drying processes to prepare them for further extraction. Once mined, the smelting of laterite requires large amounts of energy, which comes mainly from fossil fuels. While sulphide mining is cleaner, it presents other environmental challenges. The mining and processing of sulphide ores releases sulphur compounds and heavy metals into the environment, which, if not managed properly, can lead to acid mine drainage and water contamination. In addition, nickel sulphide is typically more expensive to mine due to its rock-hard nature. Lithium Emissions per Extraction Process Lithium is the main component of rechargeable batteries in mobile phones, hybrid cars, electric bicycles and grid-scale storage systems. Currently, there are two main methods of lithium extraction:From brine, lithium-rich brine is pumped from an underground aquifer to an evaporation pond where solar energy evaporates the water and concentrates the lithium content. The concentrated brine is further processed to extract lithium carbonate or hydroxide. Hard rock mining, or extraction of lithium from ores (mainly lithium pyroxene) in pegmatite deposits. The world's leading lithium producer, Australia (46.9 per cent), extracts lithium directly from hard rock.

Mining involves drilling, blasting and crushing the ore, followed by flotation to separate the lithium-bearing minerals from other minerals. This type of extraction has environmental impacts such as land disturbance, energy consumption and the generation of waste rock and tailings. Sustainable production of lithium and nickel Environmentally responsible practices in the extraction and processing of nickel and lithium are essential to ensure the sustainability of the battery supply chain. This includes enforcing strict environmental regulations, improving energy efficiency, reducing water consumption and exploring cleaner technologies. Ongoing research and development efforts focused on improving extraction methods and minimising environmental impacts are essential.