Correlación Pesca Industrial Responsable y PBI Real

The current generation of BEVs and PHEVs utilise lithium-ion batteries (Kalhammer et al., 2007), which are preferred for use in BEVs and PHEVs because they have specific energies twice that of Nickel Cadmium batteries, high nominal cell voltages, and good load characterises with a flat discharge curve offering effective utilisation of the stored energy with a voltage spectrum ranging from 3.7 to 2.8 V/cell. These batteries are low maintenance because they do not require periodic discharge, with no memory effect²⁹, and low self-discharge. They require tighter voltage tolerance during charging and will not tolerate overcharging, so there can be no trickle charge once the battery is at full charge (Buchmann, 2011, p 122).

There is a variety of lithium-ion batteries currently considered suitable for use in EVs depending on the chemical composition of the cathode and anodes. Current lithium-ion batteries use lithium-graphite composition for the anode, except for the lithium titanate oxide, or LTO, battery which uses lithium titanate as the anode material. The most common chemistries used for the cathode are: (1) LiCoO2, which was the first lithium-ion battery developed; (2) LiMnO2 spinel, known as LMO; (3)

29 An effect seen in nickel cadmium batteries where the battery gradually loses energy capacity if repeatedly recharged after only being partially discharged.

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LiFePO4, known as the iron phosphate or LFP battery; (4) LiNiMnCoO2, known as the NMC battery; and (5) LiNiCoAl, known as the NCA battery (Burke and Miller, 2009;

Buchmann, 2011, p. 49) (Table 4.3).

Despite their advantages, these batteries do not meet all of the United States Advanced Battery Consortium’s (USABC) goals, which are seen by the United States automobile industry as the minimum goals required for successful EV

commercialisation. The shortcomings relate to energy capacity, in terms of both battery weight (specific density) and volume (energy density), battery cost, and operating temperature range (Table 4.3) (Kalhammer et al., 2007).

Graphite anode lithium-ion batteries currently attain values, at the battery pack level, of 90-150 Wh/kg and 220-330 Wh/L depending on the cathode chemistry.

LTO batteries have lower energy densities than lithium-ion batteries that use graphite anodes. Due to their fast charging capability and high charging cycle life, LTO batteries are considered more suitable for organisations operating LPV fleets that can return to a depot with fast charging facilities (Burke and Miller, 2009). In comparison, petrol and diesel fuels have specific density and energy density values of approximately 12,000 Wh/kg and 9,700 Wh/L. The effect of the low energy densities in lithium-ion batteries is that an EV with a 500 kg battery can travel about 325 km whereas an ICEV, assuming average energy efficiency, using 50 kg of petrol will travel approximately 660 km.

The price of lithium-ion battery cells has declined from over US$3,000/kWh in 1992 to an average cell price of US$400/kWh in 2012 and a battery pack, of the order of 30 kWh, would cost approximately US$21,000 or US$700/kWh (Element Energy Limited, 2012). For widespread commercialisation of EVs, the USABC of the United States Council for Automotive Research considers that prices of battery packs must decline to at most US$150 per kWh, in 2012 dollars, or by another 79% (U.S.

Advanced Battery Consortium, 2012).

The operating temperature range of an EV battery is important in regions with extreme climates and is particularly important in the United States. At low

temperatures, the power output of the battery declines and high temperatures can

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reduce the life of the battery. To address these limitations, lithium-ion batteries must have thermal regulation, but this adds further to the weight and cost of an EV battery (Srinivasan, 2008).

PHEV batteries have different requirements from BEV batteries. PHEV batteries must be able to provide sufficient power for acceleration and cruising speeds while using a smaller battery. Lithium-ion batteries meet the power requirements for PHEVs currently in the market, but it is considered that further battery

development is needed to meet the power, weight, and volume requirements necessary for a mid-size passenger PHEV with a 70 km all-electric-range and, at the same time, provide assurance that 3,000 to 5,000 “charge-depleting” deep

discharge cycles can be achieved (Burke and Miller, 2009; Pesaran et al., 2009).

4.5.2 Future potential

Research into advanced lithium-ion batteries is now focused on the development of high voltage cathode materials and the use of silicon anodes. Silicon anodes have shown potential for increased energy density with the potential to have cell level specific energy of up to 800 Wh/kg, but silicon anodes experience rapid capacity decay resulting in reduced cycle life (Lee et al., 2011). An alternative to silicon anodes are silicon-graphite composite anodes, which have cell level specific energy levels of up to 500 Wh/kg, but greater cycling capacity. This technology is expected to be available for use in EVs before 2020 (Amine et al., 2012; Doeff, 2011).

To achieve even higher energy densities will require the use of non-lithium-ion technologies. At present, research is focused on zinc air, lithium sulphide, lithium sulphur, lithium air, and metal air batteries (Figure 4.2). These technologies are at an experimental stage and it is uncertain when, or if, they will be available for use in EVs (Srinivasan, 2008).

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Table 4.3: Summary of characteristics of lithium-ion batteries

Specifications Lead Acid NiCd NiMH Lithium-ion Petrol

Chemistry

(80% discharge) 200-300 1,000 300-500 500-1,000 500-1,000 1,000-2,500 1,000-2,000

1,000-2,000 >5,000 >1000 n/a

stable Stable Moderately stable Sources: Buchmann (2011), Pesaran et al. (2009), Srinivasan (2008), Element Energy Limited (2012).

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Figure 4.2.: Specific energy (Wh/kg) of various electrochemical cells

Source: Srinivasan, 2008

The capacity for further reductions in the price of EV grade lithium-ion batteries remains uncertain with contemporary market projections expressing a range of views. More conservative projections assume that the price of lithium-ion battery packs will probably remain within the present range of prices of around US$700 per kWh, or only decline slightly so that, by 2020, the price is projected to be US$400 per kWh (Lux Research, 2012). More optimistic projections indicate faster

reductions in lithium-ion battery pack prices. Sankey et al. (2010) project declines to US$250/kWh by 2020. Hensley et al. (2012) were even more optimistic projecting prices of US$200/kWh by 2020 and US$160/kWh by 2025 (in 2011 dollars).

These projections are based on different views about the future cost of materials, rate of improvement in manufacturing processes, effect of increasing economies of scale, and the effect of competitive pressures lowering component prices.