Road transport efficiency

3.11.1 Electric vehicles

Critical metals including rare earths are found in many applications within electric vehicles. Examples include cerium and lanthanum in fuel additives and rare earths in LCD screens. In this instance the focus is on the applications where the largest amounts of critical metals can be found, namely the electric drive motor and battery pack. The materials demand for electric vehicles varies depending on the range and type of vehicle and the battery used. A summary of these different materials demands is given in Table 53. To estimate the materials requirements of batteries and motors for the different vehicle types, the vehicle specifications are shown Table 54 (MIT, 2008). The battery types and market shares are shown on the next pages. For graphite, it is noted that very substantial losses occur in the production of spherical battery grade graphite. These losses can be up to 70-75% of the raw material - flake graphite (Industrial

Minerals, 2012) - and the processing waste is not recoverable for use in batteries. To a certain extent there are manufacturing losses associated with all of the technologies and metals. However, as an indus- trial mineral, the physical properties are as important as the chemical properties, which limit the recycling potential of graphite. In contrast, manufacturing losses for metals are more readily recyclable.

Table 53: Materials demand for battery- and drive motor-types* in kg per vehicle, by vehicle type Material BEV HEV PHEV-50 Mild hybrid FCV

Li 4.52-7.81 0.09-0.16 0.77-1.33 - 0.12-0.21 Ni 0-46.65 0-6.67 0-7.97 - 0-1.26 Co 0-13.91 0-1.16 0-2.38 - 0-0.38 La - 0-1.16 - - - Nd 2.80 0.76-1.12 1.46 0.36 2.91 Pr - 0-0.08 - - - Sm - 0-0.08 - - - Mn 0-60.07 0-1.25 0-10.26 - 0-1.63 Cu 0-71.08 0-1.48 0-1.93 - 0-0.1.93 Ti 0-38.78 0-0.81 0-6.63 - 0-1.05 Dy 0.28 0.14-0.29 0.22 0.05 0.43 B 0.09 0.03 0.04 0.01 0.09 Graphite 0-85.94 0-1.79 0-14.68 - 0-2.33 Ce - 0-0.77 - - -

*fuel cell vehicles (FCV), battery electric vehicles (BEV), plug-in electric vehicles (PHEV), mild hybrids (mild HV) and hybrid electric vehicles (HEV).

Table 54: Vehicle specifications for different types of electric vehicles HEV PHEV-50 BEV FCV

Motor power (kW) 25 40 70 90

Battery energy (kWh) 1.0 8.2 35 1.3

Battery Power (kW) 28 45 75 40

Specific energy (Wh/kg) 100 135 150 100 PHEV-30 = plug-in hybrid with a 50 kilometre all electric range. Batteries for electric vehicles

Improving battery technologies is paramount to lowering overall vehicle costs and improving perfor- mance. There are two types of battery which are under consideration; these are nickel metal hydride (NiMH) batteries and lithium-ion (Li-ion) batteries. For HEVs, the market share predictions for battery types from Deutsche Bank are used, as shown in Table 55 (Deutsche Bank Global Markets Research, 2008).

Table 55: Market share of HEV batteries

2015 2016 2017 2018 2019 2020 2025 2030

NiMH 70% 65% 60% 50% 40% 30% 1% 0%

Li-Ion 30% 35% 40% 50% 60% 70% 99% 100% Nickel metal hydride batteries

NiMH batteries currently dominate the HEV market and have been the battery of choice for the Toyota Prius since it was first introduced. However, for BEVs and PHEVs NiMH cannot compete with Li-ion batter- ies due to their lower energy density and due to their relatively low deep-cycling capability. Consequent- ly, Toyota has decided to use Li-ion batteries for their new plug-in hybrid model. As NiMH batteries are not widely used in BEVs or PHEVs, they will only be considered for hybrid electric vehicles. The metals requirements for an HEV NiMH battery are shown in Table 56; it has been assumed that the battery alloy used is AB5.

Table 56: Metals requirements for NiMH batteries for HEVs in kg per vehicle

Metal HEV Ni 6.67 Co 1.16 La 1.16 Ce 0.77 Nd 0.23 Pr 0.08 Sm 0.08 Lithium-ion batteries

The main battery chemistry for the foreseeable future is expected to be Li-ion, and in 2011 they account- ed for over 40% of the battery chemistry split; this is expected to rise to over 80% in 2015 (Frost & Sulli- van, 2011a). The composition of Li-ion batteries varies depending on the cathode chemistries employed. The amount of lithium varies significantly across the different types, from around 0.2 kg to 10 kg per vehicle. Battery packs found in electric vehicles contain a range of materials, with the active materials typically representing less than 50% of the overall weight. Other materials found include copper for wiring and electrical parts, aluminium and plastics for casings and small amounts of precious metals in printed circuit boards.

Four different cathode chemistries have been chosen for further investigation, presented in Table 57. Although, there are currently many types of Li-ion batteries in the pipeline, such as lithium air, the focus of this study is on these four battery types as they are likely to be the most widely used for the short-to- medium term. It is expected that these battery types will be optimised for use in EVs in the near term and in the longer term, new battery chemistries with higher energy densities will be developed (IEA, 2011a). All of these battery chemistries are currently in commercial use in electric vehicles and are therefore well characterised. It is worth noting that the exact compositions of cathode chemistries vary with supply, and it is possible to have dual composite cathodes where two different active materials are used.

Table 57: Characteristics of different Li-ion batteries* by cathode chemistry (Saft Groupe SA, 2009)

NCA LFP LMS-titanate NMC

Energy (Wh/kg) Good Average Poor Good

Power Good Good Good Average/good

Calendar life Very good Poor above 30°C Poor Good

Cycle life Good Good Average Good

Safety (per kWh) Poor Good Average Poor

Cost High Average Average High

Maturity High Low High Medium

*nickel cobalt aluminium (NCA), lithium iron phosphate (LFP), lithium manganese spinel (LMS), nickel cobalt manganese (NCM)

Figure 17: Battery pack component breakdown by weight (%)

Source: Gaines et al., 2010

Nickel cobalt aluminium (LiCo0.15Al0.05O2) battery types (NCA) are similar to lithium cobalt oxide (LiCoO2)

which are commonly used in laptop batteries and mobile phones. The advantages of NCA batteries are that they have good energy and power densities; however, they are expensive compared to other battery types. Toyota’s plug-in Prius uses NCA batteries (Committee on Climate Change, 2012).

Table 58: Materials requirements in kg per vehicle for NCA battery types Material BEV HEV PHEV-50 FCV

Li 6.23 0.13 1.06 0.17 Ni 46.65 0.97 7.97 1.26 Co 8.44 0.18 1.44 0.23 Al 1.35 0.03 0.23 0.04 Graphite 72.19 1.50 12.33 1.96 Cu (anode) 66.82 1.39 11.41 1.81

Lithium iron phosphate (LiFePO4) based batteries (LFP) have superior thermal and chemical stability

compared to other Li-ion technologies. However, phosphate batteries have lower energy densities than cobalt batteries (Axeon, undated). They are used in electric vehicles manufactured by BYD, who also manufacture LFP cells (Axeon, undated; CreditSuisse, 2009a).

Table 59: Materials requirements in kg per vehicle for LFP battery types Material BEV HEV PHEV-50 FCV

Li 4.52 0.09 0.77 0.12

Fe 39.08 0.81 6.68 1.06

Graphite 85.94 1.79 14.68 2.33 Cu (anode) 79.54 1.66 13.59 2.15

Lithium manganese spinel oxide batteries (LMS) provide a higher cell voltage and are more thermally stable than cobalt-based batteries. An advantage of this cell chemistry is that it is based on manganese which is relatively non-toxic and inexpensive. In this instance they are considered with a lithium titanate oxide anode instead of a graphite anode, as these are often used in conjunction with each other. Com- pared to graphite anodes, lithium titanate anodes offer better power and rate capability (Axeon, n.d.).

Table 60: Materials requirements in kg per vehicle for LMS-titanate battery types Material BEV HEV PHEV-50 FCV

Li 7.81 0.16 1.33 0.21

Mn 60.07 1.25 10.26 1.63

Cu (anode) 71.08 1.48 12.14 1.93

Ti 38.78 0.81 6.63 1.05

Nickel cobalt manganese (LiNixCoyMnzO2) batteries (NCM) offer a compromise of cost and electrochemi-

cal performance, and in terms of energy density they are superior to LFP batteries. NCM batteries can be found in many consumer electrical goods and in EV prototypes (Committee on Climate Change, 2012).

Table 61: Materials requirements in kg per vehicle for NCM battery types Material BEV HEV PHEV-50 FCV

Li 4.64 0.10 0.79 0.13 Ni 14.43 0.30 2.46 0.39 Co 13.91 0.29 2.38 0.38 Mn 12.88 0.27 2.20 0.35 Graphite 53.08 1.11 9.07 1.44 Cu (anode) 49.13 1.02 8.39 1.33 Electric drive motors

Permanent rare earth magnets are the dominant technology used for motors in all types of electric vehicles. A few exceptions, such as the Tesla Roadster and the Mini-E, use induction motors (Bauer et al., 2011). Hybrid and electric drive train applications typically use 8.7% dysprosium (by weight) in their magnets (Bauer et al., 2010). The materials composition of the permanent magnet motors used for the different vehicle types is shown in Table 62.

Table 62: Magnet composition (%) of drive motor by vehicle type HEV

(2012)

HEV (2020-)

PHEV-50 BEV FCV Mild Hybrid Nd 22.5 27.0 27.0 27.0 27.0 27.0 Fe 66.0 66.0 66.0 66.0 66.0 66.0

Dy 8.5 4.0 4.0 4.0 4.0 4.0

B 1.0 1.0 1.0 1.0 1.0 1.0

The majority of electric vehicles use NdFeB permanent magnet technology for their drive motor, however some EVs currently on the market use induction motors and to reflect this, these have been included into our model. Induction motors do not require permanent magnets and therefore rare earth elements, instead they use copper coils to produce a magnetic field. Consequently, their requirements for copper are relatively high, for instance a typical induction motor for a fully electric BEV requires 80kg of copper.

Table 63: Metals requirements for electric drive motors in kg per vehicle Motor Type Material HEV

(2012)

HEV (2020-)

PHEV BEV FCV Mild hybrid Permanent magnet Nd 0.76 0.91 1.46 2.55 2.92 0.36 Fe 2.25 2.25 3.6 7.65 8.1 0.90 Dy 0.29 0.14 0.22 0.38 0.38 0.05 B 0.025 0.025 0.04 0.085 0.09 0.01 Induction Cu 25 25 40 70 80 10

3.12 Desalination

A key material need in desalination plants of any type is for corrosion resistant materials. The choice of material is a compromise between investment and operating costs, performance and durability. The required characteristics for the corrosion resistant materials vary depending on the type of desalination plant (multi-stage flash distillation-MSF, multiple-effect distillation-MED, reverse osmosis-RO) and the corrosive conditions in different sections of the desalination plant (e.g. tubing, valves, pumps or evapora- tion chambers). The most severe conditions are found in MSF plants followed by MED plants. Conditions in RO plants are much less severe as they operate at low temperatures (< 70°C; Malik and Kutty, 1992; Richaud-Minier et al., 2007)

3.12.1 Thermal plants

Different metals and alloys are used in different sections of thermal desalination plants. In addition, due to choices for each section that also have to do with raw material pricing in addition to technical charac- teristics, the raw material profile of different thermal plants of the same type is also different. For exam- ple, MSF plants in Saudi Arabia at the turn of the century used mostly steel, stainless steel, copper-nickel alloy and titanium for parts such as (Malik and Kutty, 1992; Hamed et al., 2001):

• Brine heaters – shell made from carbon steel and tubes made from 70/30 or 90/10 Cu-Ni alloy, but with exceptions (Ti tubing). It is worth noting that heat exchanger tubes are the single largest procurement item in an MSF plant and at the same time account for 70% of corrosion failures. • Flash chambers – carbon steel with and without cladding of some or all of the chambers; clad-

ding in some plants is made out of stainless steel or 90/10 Cu-Ni alloy.

• Heat rejection tubes – mostly made from Ti but with exceptions (90/10 Cu-Ni).

Generally, Ti is used for the parts most at risk of corrosion and copper alloys for the less critical parts (Richaud-Minier et al., 2007). However, due to high costs for Ni and Ti, high alloy steels with up to 29% Cr (Richaud-Minier et al., 2007; Richaud-Minier, 2008) have become competitive both in performance and costs. Duplex stainless steel (21.5-25% Cr, 1.5-7% Ni, 0.3-4% Mo) can be used for critical components in both MSF and MED plants (Outokumpu, 2010, 2012a, 2012b). For MED and MSF facilities, the most relevant metals for desalination technologies are Fe, Cr, Ni and Mo for stainless steel, Cu-Ni alloys, and Ti (also with Pd as an alloying element; Angerer et al., 2009). Examples of stainless steel requirements for MED and MSF facilities are Marafiq in Saudi Arabia with 10,000 tonnes stainless steel and 800,000 m3/d capacity and Shuweihat 2 in the United Arab Emirates with 5,800 tonnes stainless steel and 100 MIGD capacity, yielding metal requirements of the order of 3 kg Cr, 1 kg Ni and 0.5 kg Mo per m3/d of capacity (Outokumpu, 2012a, 2012b).

3.12.2 Reverse osmosis plants

In the case of RO plants, components like pumps, valves and pipes as well as the casings for the mem- brane modules need to be resistant to corrosion. As the conditions are less severe than in thermal desali- nation plants, lower Cr contents are acceptable (> 15% Cr; Oldfield and Todd, 1986; Malik and Kutty, 1992; Malik and Andijani, 2005); for example, stainless steel type 1.4571/316Ti8 which is considered of ‘marine grade’ but is not resistant to warm sea water (aalco, 2012; Saravia, 2012).