COP28 Series: Lithium 

As the global push to transition from fossil fuels to renewable energy sources accelerates, the demand for lithium - a critical component in current electric batteries - is predicted to surge. Electric batteries play a vital role in two primary areas aimed at reducing our dependence on fossil fuels: electric vehicles and energy storage (particularly from intermittent renewable generation).

At COP28, 121 countries signed the Global Renewables and Energy Efficiency Pledge. This ambitious pledge highlights the International Energy Agency and the International Renewable Energy Agency forecast that, to limit warming to 1.5°C, the world requires three times more renewable energy capacity by 2030 (or at least 11,000 GW) and must double the global average annual rate of energy efficiency improvements from around 2% to over 4% every year until 2030.

This marks a significant step towards decarbonizing the energy system and reducing reliance on fossil fuels.  However, it also highlights that the demand for lithium is about to soar. Can lithium deliver on its sustainable promises?

Lithium-ion batteries

Lithium-ion batteries operate by moving lithium ions through an electrolyte between the anode and cathode during charging and discharging cycles. When the battery is charging, lithium ions move from the cathode to the anode, storing energy. During discharge, the ions travel back to the cathode, releasing energy to power devices. The electrolyte facilitates ion transport while a separator prevents direct contact between the anode and cathode.

The finite lifetime of lithium batteries is primarily due to the chemical and physical changes that occur during charge and discharge cycles. As batteries age, their ability to hold a charge diminishes, leading to reduced performance and eventual failure.

Lithium extraction

Lithium is primarily extracted from two sources: brine deposits and mineral ores. Both raise issues from an environmental perspective.

Extraction of lithium from brine deposits occurs primarily in the “Lithium Triangle”: Argentina, Bolivia and Chile.  This method involves pumping lithium-rich brine from underground reservoirs to the surface, where it is left to evaporate in large ponds over the course of months or years until most of the water is removed. This process, while visually not particularly disruptive, can lead to water shortages in arid regions, as well as soil and water contamination from the chemicals used in extraction.

Hard rock mining for lithium extraction takes place in countries such as the Democratic Republic of Congo and Australia. This method looks like traditional mining, in which lithium-rich minerals such as spodumene are extracted from the ground, crushed, heat-treated and chemically treated to extract lithium. As with any mining, this method results in significant land disruption and water use, leading to habitat destruction and soil erosion.

Addressing the environmental challenges associated with lithium mining is crucial as the demand for lithium surges to meet the needs of the EV market, renewable energy storage and other industries relying on lithium supply.

One potential solution to the environmental impacts of conventional lithium mining is to seek alternative sources of lithium. For instance, it is estimated that the ocean contains 230 billion tons of lithium – four orders of magnitude larger than the lithium reserves on land. Additionally, a significant amount of lithium is locked away in used batteries and other electronic devices, leaving ample scope for new innovation in this area.

Recycling of lithium batteries and improvements in battery design

Currently battery recycling methods include pyrometallurgical and hydrometallurgical processes, as well as combinations of the two processes.

Pyrometallurgical recycling involves smelting the batteries at high temperatures to recover metals, which is in some ways similar to the treatment of lithium-rich ore during mining. Hydrometallurgical recycling uses chemical solutions to leach metals from shredded battery materials. A combination of the two methods may be used to extract various elements typically found in lithium-ion batteries, such as cobalt, nickel and manganese (as well as lithium itself).

Direct recycling is another approach for recycling of lithium-ion batteries. This method involves disassembly of the battery, so that the individual elements may be reconditioned or recycled. This is more economical and has a lower environmental impact than pyrometallurgical or hydrometallurgical processes. However, this method has a number of disadvantages. Direct recycling is mostly suitable for used batteries which are generally in good condition. Also, the complex multi-material of battery designs makes them difficult to disassemble. Even once a battery is disassembled, it is difficult to systematically sort and process the constituent elements due to the differences in battery designs and material composition between various manufacturers.

Given the current abundance of lithium in Earth's reserves, recycling lithium is not currently economically viable (and may indeed be more harmful to the environment than extracting new lithium). Thus, at present, most of the lithium used in the manufacturing of batteries is sourced from previously-unused raw material.

However, the recycling of lithium-ion batteries could be made significantly less energy-intensive and less environmentally-damaging if battery designs were made simpler and more straightforward to disassemble. This approach would not only improve recycling efficiency but also support sustainability by making battery reuse and refurbishment more feasible, aligning with circular economy principles.

Alongside improved recycling methods, increasing battery lifetimes is another important area for development.  Increased lifetimes reduce the frequency of recycling and/or reduce the total amount of material needed to sustain the operational capacity of battery systems. New materials and material combinations having a high energy capacity and high cyclability are a key area where continued innovation is needed, to create batteries that have longer life.

Conclusion

As the world transitions to renewable energy and electric mobility, the demand for lithium will continue to rise, driven by the need for efficient and powerful batteries. While lithium plays a critical role in this transition, its extraction and use also presents significant environmental challenges that will need to be addressed through sustainable mining practices, advancements in battery technology, and improvements in recycling. Continued innovation and development of existing practices will be needed to meet global commitments like those made at COP28, and ensure that the move away from fossil fuels is both effective and environmentally responsible, paving the way for a sustainable energy future.

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