Ben
Davies
*a,
Jorge A.
Llamas-Orozco
a,
Fanran
Meng
*b,
I. Daniel
Posen
c,
Heather L.
MacLean
c,
Amir F. N.
Abdul-Manan
d and
Jon
McKechnie
a
aLow Carbon Energy and Resource Technologies, University of Nottingham, Nottingham, UK. E-mail: Ben.Davies@nottingham.ac.uk; Tel: +44(0) 115 951 4002
bDepartment of Chemical & Biological Engineering, University of Sheffield, Sheffield, UK. E-mail: F.Meng@sheffield.ac.uk; Tel: +44(0) 114 222 7510
cDepartment of Civil & Mineral Engineering, University of Toronto, Toronto, Ontario, Canada
dStrategic Transport Analysis Team, Transport Technologies R&D, Research & Development Center (R&D), Saudi Aramco, Dhahran, Saudi Arabia
First published on 13th June 2024
The UK zero-emissions vehicle (ZEV) mandate aims for battery electric vehicles (BEVs) to account for 100% of new sales by 2035. This study presents a fleet-scale life cycle assessment model of UK light duty vehicles through 2050, integrating a dynamic material flow analysis to evaluate the implications on critical battery materials. Rapid uptake of BEVs is projected to grow demand for primary materials within 15 years, particularly for lithium, nickel, and cobalt, exceeding current UK consumption by at least five-fold. In the longer-term, the successful creation of a closed-loop battery recycling ecosystem has the potential to mitigate further increases in demand for primary critical materials. With the adoption of efficient closed-loop, domestic recycling practice, the EU's regulations for battery recycled content requirements could be met for nickel and lithium, though cobalt remains a challenge as the recycled content targets could only be met two to three years later. The ZEV mandate is projected to be effective in reducing overall life cycle GHG emissions by 57% in 2050, relative to 2021. Even with an ambitious target like the UK's 2035 ZEV mandate, internal combustion engine vehicles will continue to operate on the road for years to come given that the fleet average is a 15 years vehicle lifetime. Thus, it is prudent to also consider low-carbon fuels as a complementary strategy to deliver the UK's net-zero target.
Sustainability spotlightThe UK government is pursuing an aggressive zero-emissions vehicle (ZEV) mandate, aiming for 100% of new passenger vehicle sales to be battery electric from 2035. Whilst the mandate could result in more than 50% reduction in overall life cycle GHG emissions, supplying the necessary critical battery materials is a potential challenge, with demand for nickel, cobalt, and lithium estimated to exceed current UK consumption by at least five-fold. In the context of the UN Sustainable Development Goals (SDG) for clean energy (SDG 7), responsible consumption and production (SDG 12), and climate action (SDG 13), we draw insights on the implications of several different electrification trajectories for the UK's light-duty vehicle sector, including the creation of a more circular battery ecosystem, a switch to a less material-intensive battery technology, a delay in the delivery of the ZEV mandate, and a more conservative uptake of renewables in the power sector. |
From a life cycle assessment (LCA) perspective, use-phase emissions are not the only consideration in a vehicle's life cycle; materials production, manufacturing, and end-of-life management are important contributors to the overall impact of vehicle technologies.5 Therefore, an LCA study can be useful for informing discussion on the overall life cycle impacts of an ZEV mandate; not just on the GHG reduction potentials, but also the resulting material implications of an aggressive electrification plan. Specifically, the widespread adoption of BEVs will raise the demand for traction batteries and the constituent critical metals used in the production of battery cathodes.
In 2022, there were 2.3 million combined hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs) and fully electric BEV light duty vehicles in the UK fleet, with 685000 new electric vehicles registered that year.6 This represents a 21% year-on-year growth in sales, with electrified powertrains accounting for 42% of the 2022 new vehicle sales market; comprising 20% HEV, 6% PHEV, and 16% BEV. With the ambitious policy targeting 100% zero-tailpipe emission LDV sales from 2035, annual new traction battery demand in the UK is projected to increase from 100 kt in 2020 to 900 kt in 2035.7 The policy targets and projected growth in the UK BEV market are indicative of similar commitments by policymakers around the world. More than 20 countries have announced electrification targets – from nations across Europe, East Asia, and Canada – projecting global electric vehicle sales to increase from 3 million in 2020 to 37 million vehicles in 2030, with the equivalent order of magnitude growth in battery demand.8 The challenge of delivering a rapid growth in electric vehicle sales simultaneously across multiple geographical regions comes with the need to better understand the demand on critical material supply and associated GHG impacts. This is particularly relevant for a country like the UK where there is currently limited domestic battery production capacity, which may hinder access to key materials and technology to achieve low-carbon targets.9
Lithium-ion batteries (LIBs) are currently the technology of choice for electric vehicle powertrains. LIBs can be further categorised based on the chemistry of the constituent cathode; leading technologies in automotive applications include lithium nickel cobalt aluminium oxide (NCA), lithium nickel manganese cobalt oxide (NMC), and lithium iron phosphate (LFP).10 The different chemistries offer varying performance characteristics that may be selected for cost, energy density, safety and reliability, or materials composition. The British Geological Society (BGS) and UK Critical Minerals Intelligence Centre (CMIC) have advised on a number of minerals with high criticality of supply, in which those relevant to battery manufacturing include lithium (Li), nickel (Ni), cobalt (Co), manganese (Mn), and graphite (Gr).9 These minerals are highlighted given projected future growth in demand, anticipated limitations in geographic availability and accessibility, and concerns over reliability of supply.
There is a growing body of work that explores the availability and flows of these critical battery materials for regions including the EU,11 China,12 and, in our previous work, the US.13 There is significant uncertainty in the future global requirement for critical minerals for batteries; overall, studies show that global annual material demands for Li, Co, and Ni are expected to far exceed production capacities, though worldwide reserves may be sufficient to meet overall requirements through 2050.14 To address this challenge, global policymakers are proposing interventions to build resilience, mitigate risks, and promote efficient use. In parallel to the UK critical minerals strategy,9 the EU has adopted regulation to set mandatory minimum levels of recycled content in new battery manufacture.15 For the prospective UK battery manufacturing industry to access the European market it will need to align with the EU's recycled content regulation.16 The targets that are initially to be met by 2031 are for 6% lithium, 6% nickel, and 16% cobalt to be derived from secondary sources, which will be raised, by 2036, to 12% lithium, 15% nickel, and 26% cobalt.
Life cycle assessment provides a methodology to study the impacts of a given product, process, or service; single LDVs are assessed for the environmental and resource implications that go into raw material processing, manufacture, logistics, fuel use in operation, and final disassembly and end-of-life treatments.17 LCA studies of single vehicles or products are traditionally static with respect to time, with constant parameters, and assuming the “life” (production, use, end-of-life) occurs at one point in time.18 This approach benchmarks vehicle design and comparable competing technologies, however, the simplifying assumptions mean the results may only be valid for a short window of time and do not evaluate the outcomes of policy across the national LDV fleet.19,20 Extending this method to incorporate temporal dynamics allows for a more representative analysis that includes emerging technologies and the evolution of life cycle processes.21 This is particularly relevant in the use-phase, where fleet operations are expected to decarbonise in the future.22–24 Vehicle battery technologies are undergoing similarly rigorous life cycle assessment.25,26 Studies have reported the GHG impacts of new battery production27,28 including our previous study, Llamas-Orozco et al.,29 which completes a state-of-the-art assessment of emissions factors in the global supply chains for LIB materials.
Extending the LCA method to assess many vehicles, their concurrent lifetimes, and the future development of technologies, produces a fleet-scale LCA model uniquely suited to analyse the transport sector.30 This approach evaluates the impacts of many individual vehicles, and accommodates the evolution of technologies over time, interactions with the energy sector, and the potential outcomes of planned transport sector policies. Recent studies have assessed LDV electrification in fleet-scale LCA methods for North America,5,31,32 Europe,33–35 and Asia.36,37 Previous fleet-level LCA and materials flow analysis (MFA) studies for the UK market7,38 consider a limited set of vehicle technologies (ICEV and BEV, excluding PHEV which constitute a significant share of the UK transport strategy39), do not consider the increasing use of LFP batteries as intended by key manufacturers,40 and have not accounted for the current UK ZEV mandate41 and EU battery recycling regulation.15
Thus, there is scope to update a UK-specific fleet LCA investigation, including more representative vehicle and battery technology combinations, and in the context of current policy. This analysis will align with the UN sustainable development goals (SDG)42 for the use of renewable energy (SDG 7), responsible consumption of mineral resources (SDG 12), and transport policies that integrate climate action (SDG 13).
This study contributes a fleet-scale life cycle assessment model to specifically examine the outcomes of the UK's aggressive electrification target. Using the ZEV mandate as input, we model the evolution of annual and cumulative GHG emissions for the UK's LDV fleet and the dynamics of critical material flows, which can then be interrogated against the intended targets under the UK's net-zero policy and EU's recycled battery content regulation.
Fig. 2 Detail of the Batteries module in the UK-FLAME model, featuring closed-loop, end-of-life recycling, and simulation inputs for battery markets and recycling processes. |
A global and dynamic perspective on the production of battery materials is employed, as published previously.29 Emission factors are quantified based on existing battery supply chains, with location-specific primary materials production and projections for future process decarbonisation. The present study focuses on the material flow analysis for five critical battery materials: nickel, cobalt, lithium, manganese, and graphite. Battery materials are summarised in the ESI,† Table S5. Recycling process recovery rates and emissions factors are discussed further in section 2.2.2.
Fuel and energy production is assigned in the year of demand. Conventional petrol and diesel fuels production are mature processes with GHG emission factors that are assumed to be static throughout the simulation. This is a simplifying assumption due to lack to information on how these processes may evolve. Grid electricity is defined as a national mix of technologies, including generation from fossil fuel, nuclear, and renewable wind, solar, and hydro sources.49 This provides the dynamic analysis for BEVs and PHEVs benefiting from renewable and low-carbon electricity generation which is deployed in parallel to the delivery of the ZEV mandate.
The GHG results calculated in the LCA module study have implications across national and international industries: in metallurgy, manufacturing, energy generation, and, of course, transportation. GHG emission results are contextualised against the ambitions of the UK's national carbon budgets. The carbon budgets have been legislated with increasing ambition, towards a pledge of net zero by 2050. The 6th Carbon Budget is defined for the period 2033 to 2037, with the fleet electrification policies featuring prominently.52 There is no definitive allocation for different sectoral emissions, however, historically, the totality of the transport sector contributes approximately a quarter to the national profile. Of transport operations, LDV fleet use phase emissions in turn contribute 50–60%, equalling the 57 Mt CO2 eq. p.a. reported in 2021. These tailpipe emissions are required to abate to approximately 0.9 Mt CO2 eq. in 2050 to deliver the net zero pledge.39 This residual value accounts for combustion-based vehicles that have not yet been retired from the fleet, with the expectation that other sectors of the economy will enable carbon-offsetting to reach economy-wide net zero. Fig. 3 shows the legislated national carbon budgets and recorded GHG emissions, projected forward to the 9th and Final Carbon Budget, 0 kg CO2 eq. for 2048 to 2050, and beyond.
Year | ZEV-2035 | ZEV-2040 | Year | ZEV-2035 | ZEV-2040 |
---|---|---|---|---|---|
2020 | 6.5% | 6.5% | 2036 | 100% | 84% |
2021 | 11% | 11% | 2037 | 100% | 88% |
2022 | 16% | 16% | 2038 | 100% | 92% |
2023 | 20% | 20% | 2039 | 100% | 96% |
2024 | 22% | 22% | 2040 | 100% | 100% |
2025 | 28% | 28% | 2041 | 100% | 100% |
2026 | 33% | 33% | 2042 | 100% | 100% |
2027 | 38% | 38% | 2043 | 100% | 100% |
2028 | 52% | 43% | 2044 | 100% | 100% |
2029 | 66% | 49% | 2045 | 100% | 100% |
2030 | 80% | 54% | 2046 | 100% | 100% |
2031 | 84% | 59% | 2047 | 100% | 100% |
2032 | 88% | 64% | 2048 | 100% | 100% |
2033 | 92% | 70% | 2049 | 100% | 100% |
2034 | 96% | 75% | 2050 | 100% | 100% |
2035 | 100% | 80% |
The UK government has however demonstrated an appetite to change the policy delivery,54 moving the sales ban on new ICEVs from 2030 to 2035; thus, the ZEV-2040 scenario examines the potential for five years of further delay to the ZEV mandate. This delayed scenario is defined as a more linear transition from 2024 to 2040. BEVs are considered the ZEV solution for the UK light-duty vehicle market.39 Other technologies, such as hydrogen fuel cells, are at an earlier stage of development and deployment, and their future success in the fleet is uncertain.55
Alongside the deployment of BEVs in the market, PHEVs are seen as an important lower-emission technology in the transition to a 100% ZEV fleet.55 The historic sales share for PHEVs has been growing alongside BEVs, reaching 6% of the market in 2022.6 The UK Committee on Climate Change suggest sales of PHEVs could peak at 25% in the 2030s, before declining with all other non-ZEV technologies.39 The sales for ICEVs and HEVs are decreased proportionally from the current share to complete the market.
For the selection of the closed-loop recycling process, two existing and commercialised technologies have been identified: the pyrometallurgical process57 and the hydrometallurgical process.58 Pyrometallurgy is emissions intensive and only able to recover nickel and cobalt from the end-of-life battery, whilst hydrometallurgy is more complete, also recovering lithium, manganese, and graphite.29,59,60,61
Table 2 summarises the emissions factors associated with the primary and secondary processing of the critical materials to the metal salts that are used in battery manufacture. Mass allocation is followed to estimate the emission intensity as, in the context of this closed-loop recycling process, all economic value remains in the transportation system, displacing the need for primary material production.
Material | Primary production emissions factor, kg CO2 eq./kg | Recycling process | Recycling process allocateda emissions factor, kg CO2 eq./kg | Recovery rate |
---|---|---|---|---|
a Allocation by mass recovered. | ||||
Nickel sulphate | 18.53 | Pyro | 9.78 | 98% |
Hydro | 2.28 | 98% | ||
Cobalt sulphate | 7.33 | Pyro | 9.78 | 98% |
Hydro | 2.28 | 98% | ||
Lithium carbonate | 13.08 | Pyro | — | 0% |
Hydro | 2.28 | 90% | ||
Lithium hydroxide | 24.80 | Pyro | — | 0% |
Hydro | 2.28 | 90% | ||
Manganese sulphate | 1.43 | Pyro | — | 0% |
Hydro | 2.28 | 90% | ||
Graphite | 4.44 | Pyro | — | 0% |
Hydro | 2.28 | 90% |
The second electricity scenario represents more conservative grid decarbonisation, in line with the rate projected as a European average by the IEA Global Energy Outlook.3 In comparison, this projection would expect a higher share of natural gas generation maintained into the future. By 2050, the conservative case predicts generation at 120 g CO2 eq. per kW h. This scenario will test the outcomes of the ZEV mandate for sensitivity to a higher-carbon intensity electricity source. Detail of the grid decarbonisation projections can be found in the ESI,† Fig. S4.
Scenario | Fleet market | Battery chemistry | Battery recycling | Grid mix |
---|---|---|---|---|
Core scenario | ZEV-2035 | NCX | Pyro | Base |
Delayed policies | ZEV-2040 | NCX | Pyro | Base |
Improved recycling | ZEV-2035 | NCX | Hydro | Base |
Reduced cobalt batteries | ZEV-2035 | LFP | Hydro | Base |
Delayed policies with reduced cobalt batteries | ZEV-2040 | LFP | Hydro | Base |
Conservative grid decarbonisation | ZEV-2035 | NCX | Pyro | Conservative |
Fig. 5 Projections for annual primary critical battery materials in the UK, alongside 2020 UK consumption as reported by:63 nickel 19 kt, cobalt 3 kt, lithium 400 t, manganese 52 kt (out of scale), graphite 17 kt. |
For all five materials, primary demand is projected to increase significantly through 2035, corresponding to the expected growth in the sales of PHEVs and BEVs. Scenarios following the ZEV-2035 sales market, Table 1, show accelerated deployment after 2027. Peak demand is reached as the ZEV mandate is implemented fully – 2035 for the core, or 2040 for the delayed scenarios – and then most scenarios see decreasing demand through 2050 as secondary material becomes available when electric vehicles reach their end-of-life. However, for lithium, manganese, and graphite in the core scenario and delayed policies scenario demand reaches a plateau, as there is no secondary material available through closed-loop pyrometallurgical processing, and therefore modelled demand can only be met with primary materials.
The greatest demand for nickel, cobalt, and manganese is observed in the NCX battery markets; respectively peaking at 92, 20, and 15 kt in 2035 in the core scenario. For nickel and cobalt, these are significantly above the current consumption by UK industries; 4.8 times greater for nickel and 6.7 times for cobalt. However, switching to the LFP-dominant battery market can be effective in reducing the demand for primary nickel, cobalt, and manganese; peak demand is respectively 35, 7.7, and 4.7 kt in 2035 under the reduced cobalt batteries scenario.
Although an LFP-dominant battery chemistry could reduce demand for nickel, cobalt, and manganese, it raises the demand for lithium. The lower energy density of the LFP battery technology results in greater material demands to meet the same energy storage capacity for electrified vehicle powertrains. The reduced cobalt batteries scenario sees peak demand for primary lithium at 25 kt; this is a 61-times greater than the UK's current usage, with little domestic battery production. Graphite is an essential material for all battery chemistries. All scenarios see a peak demand between 140–180 kt, approximately 10 times greater than the 2020 UK demand.
Fig. 6 presents the proportion of secondary materials that are available for new LIB manufacture from the purely closed-loop vehicle recycling modelling. Fig. 6 also displays the target secondary material content shares for nickel, cobalt, and lithium, as laid out in the EU regulation.15 Secondary content requirements for manganese and graphite are not currently mandated within the EU legislation.
Fig. 6 Projection for the share of secondary critical battery materials that are used in new LIB manufacture, for five scenarios effecting materials demand. Nickel, cobalt, and lithium are presented with the 2031 and 2036 targets for recycled content from EU battery regulation.15 |
All scenarios surpass the content targets for nickel; the closed-loop recycling process is predicted to be sufficient whether pyro- or hydrometallurgy is employed in the automotive sector. The targets are partially met for secondary cobalt content. Under the NCX battery market – the core scenario, delayed policies scenario, and improved recycling scenario – the 16% target would be met in 2034, three years late, and the 26% target would be met in 2038, two years late. At most, 4% of cobalt demand would need to be obtained from non-BEV secondary sources to meet the targets. The lower overall demand in the reduced cobalt batteries scenario means that the only missed target is in 2031. The combination of delayed with reduced cobalt batteries is projected to meet all of the recycled content targets.
Closed-loop lithium recycling can also be effective for meeting the secondary content targets, assuming hydrometallurgy is followed. The inability to recycle lithium with pyrometallurgical recycling (as used in the core scenario and delayed policies scenario) means that no secondary lithium is available from end-of-life LDVs, and all recycled material would need to be sourced externally to the UK LDV fleet to satisfy the EU targets. Though no targets are in place for manganese and graphite content the wastage in pyrometallurgy is also seen, meaning all manufacturing would need to be satisfied through primary supply chains.
The availability of secondary materials for battery manufacture grows steadily through the simulation period. In the initial growth period of the BEV market, the majority of manufacturing demand will be met with primary materials, as noted in Fig. 5. In the closed-loop recycling process there is a necessary delay for BEV vehicles to age and retire from the fleet before their constituent materials may be recovered. It is noteworthy that, outside of the noted wastages in pyrometallurgy, all materials in all other scenarios could see new LIB manufacture achieved with greater than 50% of recycled content by 2050.
Fig. 7 Projection of annual UK LDV fleet GHG emissions from 2020 to 2050 under the core scenario, by simulation module contribution. |
The vehicle cycle, including raw materials production, manufacturing, and assembly for both the vehicle and traction battery, remains an important source of life cycle GHG emissions, which are projected to increase alongside the growing adoption of BEVs in the UK LDV fleet. By 2050, the vehicle cycle will contribute over 95% of the total fleet life cycle GHG emissions. Typically, battery-related activities can account for up to 50% of the total vehicle-cycle GHG emissions. Primary production of critical materials can contribute significantly to the overall battery manufacturing emissions, though the gradual decarbonisation of the supply chain and the growing use of secondary materials are expected to reduce the battery life cycle GHG emissions by 20% from its peak in 2035. However, consistent with the material flow analysis presented in the preceding section, there is an expected delay in realizing the GHG reduction from the use of secondary materials due to the time it takes for the BEVs to retire from the fleet.
The vehicle-specific materials and manufacturing contributions, excluding the battery, contribute a steady 22 Mt CO2 eq. per year throughout the post-pandemic simulation period. BEVs are still LDVs with much of the same underlying construction before the powertrain is included, and the ongoing demand for transportation will necessitate new manufacturing as older vehicles are retired from the fleet. This study has focussed on the evolution of material supply and GHG emissions contributions of battery-specific materials; the impact factors for vehicle materials remain fixed. This is a simplification which allows for the impacts of the ZEV mandate to be better understood. In reality, there might be greater decarbonisation associated with many of the supporting industries involved in the UK LDV fleet ecosystem – steel and aluminium production, component manufacture, etc. – and the emissions from these industries are also likely to decrease through 2050.
Fig. 8 shows the cumulative GHG results across the simulation period. From 2020 to 2050, cumulative life cycle LDV fleet emissions in the Core scenario total 1.97 Gt CO2 eq., of which 1.00 Gt CO2 eq. is attributable to all vehicle-cycle contributions, 237 Mt CO2 eq. to fuel production and electricity generation, and 738 Mt CO2 eq. to the direct use-phase emissions. The cumulative emissions allowance for LDV use – estimated from the planned and future carbon budgeting, Fig. 3 – is 0.8–1 Gt CO2 eq. for the same time period; the modelled result is in line with net zero 2050 targets. Importantly, this suggests that the challenges of LDV fleet electrification in the UK need to be addressed in a timely manner for the ZEV mandate to facilitate a proportionate decarbonisation in the transport sector, in-line with the UK's LDV carbon-budget to 2050. These results highlight the relative contribution of materials and manufacturing to the overall life cycle of electric vehicles, and though not investigated here, similar decarbonisation of the supporting industries would be necessary to achieve economy-wide net zero targets.
Fig. 8 Projection of cumulative UK LDV fleet GHG emissions from 2020 to 2050 for each scenario, by simulation module contribution. |
However, a delay in the implementation of the 100% ZEV mandate by 5 years to 2040 has a relatively modest 4% increase in cumulative GHG emissions in the simulation period – the cumulative use phase emissions are still within the UK's carbon-budget for the LDV sector. The higher overall lifecycle emission is due to the greater fuel production and combustion emissions – respectively, 9 and 12% greater than the reference core scenario – due to a greater proportion of ICEVs operating in the fleet. Whilst the current policy focus is to electrify LDVs, further emission reductions from the fleet could be achieved with the use of lower-carbon fuels to enable the remaining combustion-based vehicles on the road to contribute to the UK's ambitious climate mitigation target.64
Switching to the hydrometallurgical recycling process decreases fleet-scale emissions by 1.6%, with all the reduction coming from the critical materials processing. Though hydrometallurgical recycling has a much lower carbon intensity than the pyrometallurgical process, Table 2, the majority of the demand for new LIB manufacturing is met with higher-intensity primary minerals, so only a modest benefit is observed during the fleet transition. Hydrometallurgy is less industrially mature in Europe than pyrometallurgy, though considering the recent EU recycling content regulation there may be further developments in this area.
When electric LDVs are manufactured with batteries of the reduced cobalt LFP chemistry, this has the greatest potential emissions reduction of 3.6% to 1.90 Gt CO2 eq. cumulatively. Again, this decrease is achieved in the battery life cycle, combining the reduced usage of nickel and cobalt, and the effective recycling of lithium. Analysis by Tarabay et al. does indicate that the heavier LFP batteries come with a penalty in vehicle energy consumption and the associated use phase emissions,13 though this is of less impact with the lower carbon intensity for UK electricity, compared to the study's US emissions factor. Several authors do also point to the low economic value in recycling LFP batteries,65,66 indicating this scenario could be reliant on other external factors including the provision of regulatory incentives.
Importantly, the conservative grid decarbonisation scenario highlights the importance of continuing the UK's grid decarbonization trajectory. Cumulative fleet-scale GHGs are 9.9% higher in the conservative grid decarbonisation scenario (2.17 Gt CO2 eq.) than the reference core scenario, where the additional emission is attributable only to electricity generation. The degree of emissions reduction achieved by the UK's ZEV mandate is directly proportional to the speed and consistency at which the electricity powering the future BEV fleet will be decarbonised. Currently, the UK already enjoys a lower-carbon electricity generation compared to many other countries, thus offering an immediate advantage to fleet electrification.67 Nonetheless, the conservative grid decarbonisation scenario demonstrates that there are cross-cutting GHG emission savings achievable if the ambitious renewable energy generation targets are equally upheld.
An aggressive shift to BEVs could raise serious challenges for the UK – and other countries pursuing similarly aggressive BEV deployment strategies – in meeting the rapid growth in demand for traction batteries and the constituent materials. Nickel, cobalt, lithium, manganese, and graphite are all critical battery materials with existing production highly concentrated in several countries and therefore potentially posing significant risk that may expose vulnerability in the global supply chains. Our analyses reveal that the ZEV mandate in the UK could raise demand for these critical materials by several times within the decade. Of particular concern are nickel, cobalt, and lithium, which could see demand exceeding current total UK-wide consumption by 4.8, 6.7, and 40 times, respectively, in 2035 in the reference core scenario.
These are important considerations given that the UK has a very limited domestic battery production capacity to meet its demand for BEVs. The UK will need to quickly develop a resilient and diverse network of global supply in primary materials for LIBs to ensure adequate and timely access to support its ambitions for the transport sector. This dependence could remain for many years before a recycling ecosystem can be effectively put in place to recover materials. Importantly, the UK represents a relatively small LDV fleet compared to other countries that are also implementing their own ZEV mandates. In perspective, the projected 2035 demand for nickel, cobalt, and lithium in the UK under the core scenario accounts for 3.3, 15, and 14% of the total 2021 global productions, respectively.68 Therefore, the UK will have to compete for access with other regions like the EU, the US, and China, and with other industries, including the electronics sector, to ensure adequate access to these key materials to achieve its ZEV mandate.
Adopting reduced cobalt battery chemistries could be one strategy to manage the demand for critical battery materials. The LFP technology is growing in popularity among vehicle manufacturers, and could reduce the peak demand for nickel, cobalt, and manganese by over 60% in 2035, though at the compromise of greater dependence on lithium. Graphite will continue to be a key material in all LIB technologies.
To reduce the reliance on primary materials, the UK will need to quickly establish a circular battery ecosystem domestically. Recycling end-of-life batteries has great potential to manage the demand for primary materials into the future; effective application of closed-loop recycling processes could reduce peak demand by 20% for all minerals and provide approximately 60% of battery material demand in 2050. This creates increasing sustainability for the supply of critical battery materials, as the stock remains within the UK transport sector. However, the amount of secondary material available is subject to the rate of electric vehicles retiring from the fleet, which is expected to see a 10–15 years delay for the secondary market volumes to grow.
Importantly, the UK should follow the EU regulation on secondary material content in LIB manufacture to ensure future export opportunity. A closed-loop vehicle recycling strategy as modelled would allow the UK to meet the secondary nickel content requirement of the EU regulation. Similarly, lithium recycling targets could be met, though only under the application of the more complex hydrometallurgical recycling process. The targets for recycled cobalt content are projected to be missed by several years at both regulatory milestones, meaning that secondary material would need to be obtained from sources external to the LDV fleet, to meet the regulation. For example, whilst only end-of-life recovery has been explored in this study, UK-specific insights have suggested that successfully recovering scrap material from start-of-life battery manufacturing could contribute a further 4–11% of secondary material availability, helping to complete the EU recycled content targets.69
Success in meeting the EU regulation is achieved under the assumption that battery recycling processes are readily available and keep pace with the rate of vehicles retiring from the UK fleet. Pyrometallurgy is the more mature technology and is primarily deployed in Europe and North America.61 This method typically involves wasting much of the battery in combustion, and losing the important lithium to slag, making it incompatible with the proposed highly circular future manufacture. Hydrometallurgical processing has the opportunity for more complete recycling, including lithium recovery. Hydrometallurgy is however less economical in Europe, with China leading in commercialisation. New UK industry would need to be established to utilise this recycling process.
Like any prospective simulation, this study has potential limitations that may influence the findings reported. The fleet-scale LCA results are subject to many diverse interdependencies that may not be fully realised in the modelling scope and assumptions. Of particular note are the fixed parameters for the vehicle cycle materials and manufacturing. There is much uncertainty in these future technological developments, for example the decarbonisation of steel production, or vehicle design for lightweighting. By fixing the vehicle cycle, this study has focussed on the potential impact of electrification and critical material demand. Thus, these results may somewhat overestimate the combined fleet GHG emissions through 2050. For completeness, future study should combine the results of LCA studies in these areas.
Following the UK's ZEV mandate, the share of BEVs in new LDV sales is projected to grow significantly. Even when sales of all new vehicles in 2035 are BEVs, there will still be over 15 million combustion-based vehicles on the road, and over 600000 in 2050. The average vehicle lifetime in the UK is about 15 years, which means that combustion vehicles will continue to be driven on the road for many more years before they retire from the fleet. To achieve its net zero pledge, the UK may need to consider complementary strategies to decarbonise the combustion-based vehicles on the road. Lower-carbon fuels, including advanced biofuels and renewable fuels of non-biological origin, could accelerate the decarbonization of the UK fleet by specifically targeting on-road conventional vehicles.
BEV | Battery electric vehicle |
DVLA | Driver and Vehicle Licensing Agency |
GHG | Ggreenhouse gas |
HEV | Hybrid electric vehicle |
ICEV | Internal combustion engine vehicle |
LCA | Life cycle assessment |
LDV | Light duty vehicle |
LIB | Lithium-ion battery |
PHEV | Plug-in hybrid electric vehicle |
SDG | Sustainable development goal |
ZEV | Zero-emission vehicle |
Footnote |
† Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d4su00112e |
This journal is © The Royal Society of Chemistry 2024 |