Impact of Recycling on Cradle-to-Gate Energy Consumption and

Oct 17, 2012 - We aimed to develop a U.S.-specific analysis of lithium-ion battery production and in particular sought to resolve literature discrepan...
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Impact of Recycling on Cradle-to-Gate Energy Consumption and Greenhouse Gas Emissions of Automotive Lithium-Ion Batteries Jennifer B. Dunn,* Linda Gaines, John Sullivan, and Michael Q. Wang Center for Transportation Research, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States S Supporting Information *

ABSTRACT: This paper addresses the environmental burdens (energy consumption and air emissions, including greenhouse gases, GHGs) of the material production, assembly, and recycling of automotive lithium-ion batteries in hybrid electric, plug-in hybrid electric, and battery electric vehicles (BEV) that use LiMn2O4 cathode material. In this analysis, we calculated the energy consumed and air emissions generated when recovering LiMn2O4, aluminum, and copper in three recycling processes (hydrometallurgical, intermediate physical, and direct physical recycling) and examined the effect(s) of closed-loop recycling on environmental impacts of battery production. We aimed to develop a U.S.-specific analysis of lithiumion battery production and in particular sought to resolve literature discrepancies concerning energy consumed during battery assembly. Our analysis takes a process-level (versus a top-down) approach. For a battery used in a BEV, we estimated cradle-to-gate energy and GHG emissions of 75 MJ/kg battery and 5.1 kg CO2e/kg battery, respectively. Battery assembly consumes only 6% of this total energy. These results are significantly less than reported in studies that take a top-down approach. We further estimate that direct physical recycling of LiMn2O4, aluminum, and copper in a closedloop scenario can reduce energy consumption during material production by up to 48%.



INTRODUCTION Electric vehicles (EVs) are at times labeled as “zero emissions” vehicles, discounting emissions generated during the production of these vehicles and the energy that powers them. Rather than ignore the upstream impacts of EV operation, it is important to consider all stages of the EV life cycle in constructing a picture of their environmental impact. Certainly as EVs gain market share, it is essential that their adoption does not cause unforeseen adverse consequences, which could include potentially unsustainable metals (lithium, cobalt, manganese) consumption, or energy-intensive or otherwise high-impact steps in battery production. The need to understand the contribution of the battery to the environmental impact of EVs is well-recognized.1,2 The environmental impact of batteries depends on their composition and performance. Lithium-ion batteries can have varied composition.2 In our analysis, we used Argonne National Laboratory’s BatPaC model3 to design the lithium-ion battery that is the basis of our analysis as described in the Supporting Information (SI). Other authors have examined the environmental impact of EV batteries as reviewed in the SI. Table 1 provides key parameters and results for four recent lithium-ion battery life cycle analyses. One goal of our work is to resolve the conflict among these studies regarding energy consumed and greenhouse gases (GHGs) emitted from cradle-to-gate, especially during the battery assembly step. We hypothesize that this discrepancy can be attributed to the differing approaches these © 2012 American Chemical Society

studies took to defining and calculating the energy required to assemble the battery from its constituent parts, which we detail in the SI. For example, Majeau-Bettez et al.4 took a top-down approach, beginning with the energy consumption for battery manufacturing (of which battery assembly is only one element), whereas Notter et al.5 took a detailed, process-level approach to modeling the material production and battery assembly. To summarize the main feature of Table 1, top-down studies in the literature produce cradle-to-gate energy consumption for batteries that are double that of Notter et al. Similarly, GHG emissions from the top-down studies are more than three times higher than the process-level study’s results. Another key goal of our analysis is to examine the impact of recycling on battery cradle-to-gate impacts. If the energy required to recover battery materials via recycling exceeds the energy to produce them from virgin materials, recycling becomes less attractive. Similarly, if the energy consumed at the battery assembly plant far exceeds the energy required to produce materials assembled into batteries, recycling will not reduce cradle-to-gate energy consumption by very much. Previous studies, with the exception of that by the U.S. Environmental Protection Agency (EPA),7 have not addressed battery recycling impacts beyond a limited discussion4−10 as Received: Revised: Accepted: Published: 12704

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Table 1. Parameters and Results from Recent Lithium-Ion Battery Life Cycle Analyses reference Notter et al. 5 MajeauBettez et al. 4 Zackrisson et al. 6 EPA 7

vehicle type BEV PHEV and BEV PHEV PHEV BEV

cathode material

battery mass (kg)

specific energy (kWh/kg)

material production energy consumption (MJ/kg battery)

assembly energy consumption (MJ/ kg battery)

battery cradle-to-gatea GHG emissions (kg CO2e/ kg battery)

processlevel top-down

LiMn2O4

300

0.11

103

1.3

6

NCMb LiFePO4

not given

0.11 0.09

129 125

80 80

22 22

top-down

LiFePO4

107

0.09

not given

74

25

0.08−0.10

59d 218d

2.3−2.9

5 16

approach

processlevelc

LiMnO2, LiNCMb, and LiFePO4

not given

a

Includes material production and battery assembly stages. bLiNi0.4Co0.2Mn0.4O2 cThis study incorporated data from Majeau-Bettez et al., which used a top-down approach. dAssuming a battery mass of 200 kg and subtracting the battery assembly from the cradle-to-gate energy consumption from EPA.7

reviewed in the SI. The EPA examined a hydrometallurgical recovery process, a pyrometallurgical process, and a direct physical recycling process in its life cycle analysis. To protect the confidentiality of industry data, EPA aggregated the energy intensities of these three very different processes into one overall energy intensity for recycling. It reports the primary energy use for end-of-life recycling for plug-in hybrid EV (PHEV) and battery EV (BEV) batteries as a credit with values of −9 and −31 MJ/kg, respectively. Their aggregation of the three technologies precludes comparison with our results. Herein, we consider the impact of three recycling processes, a hydrometallurgical process that recovers lithium as a salt, an intermediate physical recycling process that recovers Li2CO3, and a direct recycling process that recovers LiMn2O4, on the material production energy consumption and GHG emissions of lithium-ion batteries with LiMn2O4 cathode material. These processes and their associated material and energy flows are described in full detail in Dunn et al.11 A final goal of our work is to examine battery cradle-to-gate impacts (energy consumption and air emissions, including GHGs) in a U.S. context using Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET)12 model. With the exception of the EPA’s study,7 previous research has been in a European context. We model all material production as occurring in the United States, with the exception of Li2CO3, which is produced either in Chile or Nevada. Battery assembly occurs in western Michigan, a region with several battery manufacturers (LG Chem, JCI, and A123 Systems).

batteries Notter et al.5 and Majeau-Bettez et al.4 modeled. Mass inventories for the HEV, PHEV, and BEV batteries are provided in the SI, Table S4. Next, we established the system boundary for our analysis as shown in Figure 1. We analyzed the material and energy flows for each of the components within the cradle-to-gate and recycling stages with Argonne National Laboratory’s GREET model.12,14 Our analysis is based on data from the technical literature, patents, government data, and on engineering calculations. A public technical report documents our data and methodology and provides GREET users with an explanation of how battery-related parameters in GREET were derived.11 The SI contains details of our process-level calculation of the battery assembly energy requirements. We include in this value only the energy consumed at the battery assembly plant itself. The energy consumption of the assembly step that we calculate, 2.7 MJ/kg battery, is quite close to that which Notter et al.4 report through a process-level analysis. Note that the use phase is not the focus of this paper. Use phase impacts are dependent upon vehicle characteristics, drive cycles, electricity grid mix, and other factors. Other researchers (Majeau-Bettez et al.,4 Notter et al.,5 and EPA7) have considered this stage, and it can be modeled with GREET. Additionally, although we developed material and energy flows for a pyrometallurgical recycling process,11 we do not substantially discuss it in this paper because its main aim is to recover nickel and cobalt; the lithium in batteries recycled in this process ends up in slag. Its recovery from slag is energy intensive and economically unfavorable.

METHODOLOGY To begin our analysis, we used BatPaC3,13 to develop mass inventories for batteries used in hybrid electric vehicles (HEVs), PHEVs with series configuration, and BEVs. The characteristics of the three battery types are outlined in Table 2. These batteries have specific energies comparable to the

RESULTS In this section, we present results of our analysis of the material and energy flow data from cradle-to-gate for lithium-ion batteries and consider recycling. First, we describe results for the overall battery pack including the cells, housing, and the battery management system (BMS). The BMS includes measurement devices and can control battery pack current and voltage, balance of voltage among modules, and battery thermal management, among other parameters. Next, we focus on the cathode material then undertake a sensitivity analysis examining the impact of BMS mass assumptions, battery assembly energy consumption, and the recycled fraction of the wrought aluminum used in the battery. Subsequently, we examine the impact that recycling can have on the cradle-togate energy consumption and emissions of lithium-ion batteries.





Table 2. Battery Parameters Used in this Study

power (kW) energy (kWh) mass (kg) specific power (W/kg) specific energy (kWh/kg) range (km)

HEV

PHEV

EV

30 2 19 1500 0.10 N/A

150 9 89 1715 0.11 48

160 28 210 762 0.13 160 12705

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Figure 1. Components and processes with material and energy flows in GREET. The cradle-to-gate boundary includes materials production and assembly.

environmental permits.15−17 We note that permitting documents include not-to-exceed, or worst-case, values for material and energy consumption and emissions. Thus, our analysis likely overestimates the contribution of Li2CO3 to cradle-togate battery production impacts. Documentation for Li2CO3 production in Chile indicated that the process consumes HCl, H2SO4, an alcohol (which we assume to be ethanol derived from Brazilian sugar cane), lime, and soda ash. Figure 3 displays the contributors to energy consumption during LiMn2O4 production with Li2CO3 from either the United States or Chile and shows that, of the materials consumed during cathode material production, soda ash has the greatest impact. It is imported from the western United States, and nearly half the energy associated with providing it is consumed in its transport to Chile. Once produced, Chilean Li2CO3 must travel to the United States, where we assume it is combined with Mn2O3 to produce the cathode material. Transportation of raw materials and finished product could therefore represent a sizable portion of the energy consumed to produce Li2CO3 in Chile. Our analysis indicates that transportation represents 13% and 6% of the total energy consumed to produce LiMn2O4 from Chilean- and Nevada-derived Li2CO3, respectively. (See SI Figure S3 for details of transportation impacts of cathode material production.) Despite the higher transportation impacts, producing Li2CO3 in Chile is still 40% less energy intensive than producing it in Nevada. Three factors that push energy consumption higher in Nevada as compared to Chile are the more dilute (by seven times) lithium brine, a higher lime consumption rate, and the combustion of residual oil in two boilers. No such residual oil consumption is mentioned in Chile. If the Nevada lime consumption rate were equal to that in Chilean Li2CO3 production, Li2CO3 production in Nevada

Lithium-Ion Battery Cradle-to-Gate Analysis. The contributions of battery components to the cradle-to-gate energy consumption and GHG emissions are shown in Figure 2a and 2b, respectively. Because the batteries for each vehicle type have different compositions and masses, their cradle-togate energies by component differ although the relative contributions of each battery constituent are common. For both cradle-to-gate energy consumption and GHG emissions, wrought aluminum and copper, which constitute roughly onethird of the battery mass and are recyclable, contribute approximately half of the total impact. The cathode material contributes between 10 and 14% of cradle-to-gate energy consumption or GHG emissions. Battery assembly is no more than 6% of energy consumption or GHG emissions. This result is in contrast to the conclusions of Majeau-Bettez et al.4 but aligns with the results of Notter et al.5 Because battery assembly constitutes a minor fraction of cradle-to-gate energy consumption, avoiding impacts upstream of battery assembly through recycling becomes attractive. Battery components including the anode material (graphite), binder, binder solvent, and plastics contribute minimally to cradle-to-gate energy consumption and GHG emissions. The electrolyte components combined contribute between 9.6% and 13% of cradle-to-gate energy consumption. An examination of selected air emissions beyond GHGs revealed that copper and aluminum are the key contributors to emissions of SOx and NOx in the cradle-to-gate stages of the battery life cycle (see Figure S1 in the SI). LiMn2O4 Production. The Li in LiMn2O4 in this study derives from Li2CO3. Most Li2CO3 is currently produced in Chile, although it is also made in the United States, for example, in Silver Peak, Nevada. We examined impacts from producing Li2CO3 in both of these locations based on data in 12706

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Figure S2) and determined that the roasting process that produces LiMn2O4 contributes the most to air emissions during its production. Our analysis focuses on air emission impacts, but we did qualitatively examine emissions to water from the Nevada Li2CO3 facility in Silver Peak, operated by Chemetall Foote Corporation, and did not uncover any releases to the environment that posed significant risk18 (see SI for a brief discussion). For example, arsenic is present in emitted water but at levels below those established in regulatory standards. Sensitivity Analysis. We selected three parameters to be the subject of a sensitivity analysis, the results of which are in Figure 4. First, we examined the impact of increasing the

Figure 4. Impact of selected parameters on total energy consumption (MJ/kg battery).

Figure 2. (a) Life-cycle energy consumption of battery components (MJ/kg battery), and (b) life-cycle GHG emissions of battery components (gCO2e/kg battery). Components marked with an “a” make up the electrolyte. Polyvinylidene fluoride and N-methyl-2pyrrolidone (NMP) are the binder and binder solvent, respectively.

recycled fraction of the wrought aluminum used in battery assembly to 100%. (GREET assumes that wrought aluminum is 11% recycled content by default.) We used the energy consumed to produce recycled wrought aluminum from GREET rather than the energies from the recycling process because this pathway is well established, whereas the recycling processes are under development. Using all-recycled aluminum in the case of the BEV reduces total energy consumption during BEV production by 33%. Next, we examined the impact of the energy consumed during battery assembly. As described earlier, Majeau-Bettez et al. 4 reported a significantly higher value for energy consumption in this stage, although we suspect that their value includes more than solely the energy consumed in the assembly plant. If we assume that the dry room and cycling consume only 20% rather than 60% of the energy that the assembly plant uses, the purchased energy consumption at the assembly stage increases from 2.7 to 8.1 MJ/kg batteryan increase of 300%. This increase raises total energy consumption for BEVs by 12% but the resulting energy consumption remains well below that described by Majeau-Bettez et al. Finally, we investigated the impact of increasing the mass of the BMS, which we model as a collection of semiconductors and circuits (Dunn et al.11). In their work, Majeau-Bettez et al.4 and Notter et al.5 assume that the BMS is 3% and 0.34% of total battery mass, respectively, whereas in our analysis, this percentage ranges from approximately 0.9% to 1.5% of total battery mass based on measurements of a battery pack.11 Nelson et al.13 use a BMS mass of 2 kg for HEV batteries and 4 kg for PHEV and BEV batteries. Adopting the latter assumption in our sensitivity analysis represented the worst-

Figure 3. Contributions to energy intensity of LiMn2O4 production with Li2CO3 from Chile and Nevada.

would still be 25% more energy intensive. We conclude that producing Li2CO3 “locally” in Nevada does not offer a clear energy benefit for U.S. lithium-ion battery production. On the other hand, for U.S. manufacturers to tap a domestic Li2CO3 source would offer energy security benefits, and domestic sourcing of Li2CO3 would not burden the cradle-to-gate energy consumption of lithium-ion batteries significantly. We also analyzed air emissions during the production of LiMn2O4 (see 12707

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production of virgin LiMn2O4 in Nevada and Chile. We included the energy associated with the recycling processes in black boxes. Figure 5 indicates that the production of virgin LiMn2O4 is likely more energy intensive than all three of the recycling techniques. Although the hydrometallurgical process itself is not very energy intensive, consumption of citric acid and hydrogen peroxide contributes significantly to the energy consumption of the overall process. As a result, it is the most energy-intensive recycling pathway examined here. The hydrometallurgical and intermediate physical processes share a common need for the postprocessing of Li2CO3 with Mn2O3 to produce LiMn2O4. The production of Mn2O3 and LiMn2O4 contributes between 73% and 84% of the total energy consumption of these processes. The direct physical recycling process avoids use of additional Mn2O3 by recovering the cathode material, which needs minor relithiation, directly. Figure 6 illustrates the reduction in total energy consumption that may be possible when combinations of LiMn2O4,

case scenario. We therefore adjusted BMS mass assumptions to match those of Nelson et al. and observed that cradle-to-gate energy consumption increases ranged from 4.2% to 51%, depending on battery type. Taken together, the results of the sensitivity analysis show that first, it is unlikely that the energy consumed during assembly exceeds 10 MJ/kg as a rough upper bound, which is well below the results of both Majeau-Bettez et al.4 and Zackrisson et al.6 for this life-cycle stage. Second, the results demonstrate a need for better BMS mass and composition data, which could have a significant impact on total battery energy. Finally, they demonstrate the beneficial impacts that using recycled metals can have on battery cradle-to-gate energy consumption. Recycling. Dunn et al.11 fully describe the recycling techniques discussed in this paper; the SI contains a brief overview. We note that presently, recycling technologies target cobalt recovery because cobalt has a higher value than lithium. As we described earlier, a commercial pyrometallurgical process recovers cobalt but not lithium. In our analysis, we therefore compare three other recycling pathways to recover LiMn2O4. The first process is a hydrometallurgical process, still under development, that recovers lithium as a salt. Toxco operates the second, commercial intermediate physical recycling process (with cobalt-containing cathodes) that recovers Li2CO3. In both of these cases, our calculations include steps to upgrade process products (Li, Li2CO3) to LiMn2O4. Finally, OnTo Technology developed a direct physical recycling process in which cathode material and other battery components i.e., graphite, electrolyte, and metalscan be recovered. Plastics may also be recoverable. The process, which targets direct recovery of LiCoO2 after performing limited relithiation rather than extensive additional processing, is also being assessed for recovery of LiMn2O4. It is not yet operating commercially but at a bench scale. In addition, it is not clear whether the recovered cathode material will match the longterm performance of virgin cathode material. Figure 5 contains estimates of the energies expended to produce recycled LiMn2O4 from the three different processes we described and compares these energies to those for

Figure 6. Total estimated energy consumption (MJ/kg battery) of BEV batteries made from virgin materials (solid black line); with recycled cathode materials; with recycled aluminum; with recycled copper; and with recycled cathode material, copper, and aluminum.

aluminum, and copper are recycled in a closed-loop recycling scenario. GHG reductions from recycling are displayed in Figure S7. The direct physical recycling process offers the most benefit among the three processes we consider herein because it is a low-temperature process that directly recovers cathode material. We calculated how much energy is consumed in recovering Al in each recycling process and then added the energies consumed during aluminum scrap melting and casting, sheet rolling and production, and stamping from GREET12 to determine the total energy consumed in providing the recycled aluminum to battery assembly. Similarly, we calculated energy consumed to recycle copper in each process and added 50% of virgin copper production energy12 to account for processing of the recycled copper to a form that could be incorporated back into batteries. In this case of a closed-loop recycling scenario with the direct physical recycling process, nearly half of the total cradle-to-gate energy consumption of the battery made from virgin materials is conserved when cathode material, aluminum, and copper are recycled. This result highlights the importance of recovering recyclable metals from batteries. While recycling the cathode material provides a lower energy reduction benefit than recycling the aluminum, the additional benefit of conserving the supply of the metals used in the cathode

Figure 5. Estimated energy consumption for LiMn2O4 production via automotive battery recycling. Components in framed boxes are produced (Li, Li2CO3, LiMn2O4) or consumed (H2O2, citric acid, soda ash) in the recycling processes. Components outside the black boxes are consumed during upgrading of recovered lithium compounds to cathode material. 12708

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energy). This total, or full fuel cycle, energy includes upstream production of both raw materials and is nearly five times higher than the energy we calculate to produce LiMn2O4 from one of the same raw materials (Li2CO3) and roasting, a twin process to sintering. From our analysis of material and energy flows of the pyrometallurgical recycling process,11 we calculated an energy intensity of producing recycled LiCoO2 of 52 MJ/kg LiCoO2, nearly three times less than Kushnir and Sandén’s19 estimate of the total energy demand for virgin LiCoO2. If we assume that the energy intensity of the direct physical recycling process is the same for LiCoO2 as it is for LiMn2O4, the energy intensity of producing recycled LiCoO2 would be 94% less than that of producing virgin LiCoO2. Logically, then, benefits of recycling cathode material increase with the energy intensity of its production from virgin material. Considering that battery recycling can recover not only cathode material but also key metals such as aluminum and copper, overall battery recycling can reduce the total cradle-togate energy consumption of lithium-ion batteries by up to 48% when LiMn2O4, aluminum, and copper are recovered and we assume a closed-loop recycling scenario. These benefits would increase if other battery components (e.g., graphite, electrolyte) were recovered and used. Recovering additional materials in battery recycling can be facilitated through battery designs that target easy disassembly and separation of battery materials. Similarly, standardization of materials would reduce the need for separation while standardization of product design, at least in size and shape, would foster the design of automated recycling equipment. Uniformity of battery configurations and specifications would also be beneficial for reuse schemes, where cells from various sources would be tested and repackaged in compatible groups for reuse by utilities. One significant result of this analysis is that we have shown that the result of Notter et al.5 for battery assembly energy is consistent with our result. Like them, we used a process-level approach to determining this energy. Other studies using topdown approaches predict much higher rates of energy consumption during assembly. In our opinion, the processlevel approach accounts for the significant energy inputs into the assembly process and provides a more accurate estimate than that of the top-down approach. Key data gaps remain in the analysis of battery environmental impacts. Definitive assembly stage energy consumption and BMS composition data provided by the battery industry would enable analysts to significantly reduce uncertainty associated with these parameters. Additionally, process-level data for different cathode materials, such as NCM, will allow comparison among batteries with different cathodes. Finally, as recycling technologies develop, obtaining energy consumption and material flow data for these processes will address the question of how much energy and materials recycling truly conserves in the case of lithium-ion batteries.

material must be taken into account. In our analysis, we do not consider the energy benefit of recovering other battery materials that may be recoverable in the intermediate and direct physical recycling processes. Recovering these materials (e.g., carbon, electrolyte) would yield additional energy, environmental, and potential economic benefits. We reemphasize here that these technologies, although patented, are relatively immature, and exact energy consumption and emissions data are unavailable. Our results therefore serve as first approximations to the possible benefits of automotive lithium-ion battery recycling and likely have significant associated error. Further, the novelty of these technologies leaves unanswered several questions about the means of recovering the electrolyte (including LiPF6) although the direct physical process has demonstrated its recovery at the bench scale. The polyvinylidene fluoride binder could prove very challenging to recover. The degradation of these chemicals could generate harmful, halogenated compounds that must be treated to avoid their release to the atmosphere or water.



DISCUSSION Lithium-ion batteries are expected to be widely used in EVs. Understanding the environmental impacts of their production, and the potential mitigation of those impacts through recycling, is therefore important. In this work, we have identified the battery structural materials and the cathode material, LiMn2O4, as the components most impacting cradle-to-gate energy consumption and GHG emissions. Our results also demonstrate that certain battery components such as the graphite anode, binder, and plastics are not major contributors to battery cradle-to-gate impacts. These observations are in line with Notter et al.5 The contribution of the BMS to cradle-to-gate energy consumption, however, is not as clear-cut. Majeau-Bettez et al.4 report that 15% of battery cradle-to-gate fossil fuel depletion is attributable to the BMS. In our sensitivity analysis, even with maximized BMS mass, this impact came out to be below 12% of the cradle-to-gate energy consumption of a BEV battery. Notter et al. combine the BMS with the steel box and cables as part of the battery pack, which contributes more than 20% of all impacts they analyzed; the BMS contribution is therefore less than 20%. BMS design will likely change with battery chemistry and function, and its contribution to battery cradle-to-gate impacts will therefore fluctuate. For lithium-ion batteries with LiMn2O4 chemistry, we observed that producing recycled cathode materials is of small benefit for energy conservation except in the case of direct physical recycling, in which the actual active compound is maintained. Recycling of other cathode materials, however, may be of greater energy value. Benefits increase when burdens other than energy consumption, such as resource conservation, are considered. Recycling’s modest benefit to energy conservation is likely due in part to the relatively low amount(s) of energy consumed in providing lithium to the battery supply chain. We hypothesized that if the cathode material contained cobalt or nickel, the recovery of cathode material precursors would have a greater influence on energy conservation. To test this hypothesis, we entered Kushnir and Sandén’s19 purchased energy input data (reproduced in the Supporting Information) for producing LiCoO2 from the dry sintering of Li2CO3 and Co2O3 into GREET and calculated a total energy consumption of 147 MJ/kg (accounting for energy consumed in the production and delivery of the purchased



ASSOCIATED CONTENT

S Supporting Information *

Details of the lithium-ion battery design for this analysis, a brief review of the battery life cycle analysis literature, key material and energy flow data, a description of the recycling technologies examined herein, the development of the battery assembly energy, and selected results. This material is available free of charge via the Internet at http://pubs.acs.org. 12709

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ambiental (RCA); 2007. http://seia.sea.gob.cl/documentos/ documento.php?idDocumento=2184703 (accessed May 29, 2012). (16) SQM. Capitulo 2 Descripcion del Proyecto; 2001. http://seia. sea.gob.cl/expediente/expedientesEvaluacion.php?modo=ficha&id_ expediente=3521#-1 (accessed May 29, 2012). (17) Nevada Department of Conservation and Natural Resources. Class II Air Quality Operating Permit. Permit Number AP1479-0050.02; 2010. (18) Harto, C.; Argonne National Laboratory, 2011 (personal communication by email on Feb 22, 2011). (19) Kushnir, D.; Sandén, B. A. Multi-level energy analysis of emerging technologies: A case study in new materials for lithium ion batteries. J. Cleaner Prod. 2011, 19, 1405−1416.

AUTHOR INFORMATION

Corresponding Author

*Phone: 01-630-252-4667; fax: 01-630-252-3443; e-mail: [email protected]. Notes

The authors declare no competing financial interest.



ACKNOWLEDGMENTS This research was supported by the Vehicle Technologies Program in the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, under contract DE-AC0206CH11357. We thank Connie Bezanson and David Howell of the Vehicle Technologies Program for their support. In addition, we thank several Argonne colleagues for helpful discussions: John Molburg, Kevin Gallagher, Eric Rask, Andy Burnham, and Dan Santini. Finally, we acknowledge Matt Barnes of Pennsylvania State University for his assistance with data collection and analysis.



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