Hybrid Car Batteries: An Analysis of Environmental, Economical, and Health
Factors Following the Increased Popularity of Hybrid Vehicles
Author: Evan Yates
MPHP 429: Introduction to Environmental Health
Final Copy: Term Paper
Submitted: April 15, 2014
Hybrid cars, now considered among many as the “smart way to drive”, have
taken the vehicle market by storm since the christening of Toyota’s Prius in 2000.
With the heightened fear of draining the world of one of it’s most precious and rare
natural resources, oil, manufacturers turned to the automotive industry to find ways
to lessen oil usage, especially when the price of gas has gone from $1.86 in 2004, to
a nation-wide average of $3.62 in 2014. In part due to this near doubling of the price
of gas within the past decade, the frequency of hybrid vehicles on the road is rising
drastically each year, expected to reach over 10% of all cars by 2015. With a world
currently found in a newly discovered environmental-centric hope in righting the
wrongs past generations have done to the planet, hybrid cars seem to be the answer
to the looming question of, what happens when we run out of oil? Since nearly 50%
of the United State’s oil use is attributed to motor vehicles, it makes sense that this
be a prime location in which society tries to implement restrictions, or more
efficient means of use. Nearly every automobile manufacturer has met the demands
of creating a hybrid car in their yearly lineup, ranging from the Honda Civic Hybrid,
to the Ford Escape Hybrid, and even to the highly desired Tesla Model S.
While it is known that hybrid cars do have fewer chemical emissions, and in
instances with all-electric cars, zero emissions, this paper will give a thorough
analysis of the environmental implications of the drastically increased prevalence of
Lithium-ion batteries, as well as the increased manufacturing demands to
accommodate the flourishing hybrid car market. Health risks will also be discussed
in terms of ways that corporations must obtain certain chemicals to mass-produce
Lithium-ion batteries.
One of the major points of argument when debating the differing types of fuel
sources in vehicles, ranging from standard oil, to diesel, to hybrid vehicles, is
quantifying and analyzing the emission rates. Emission rates refer to the amount of
CO2 that is released from the vehicle’s exhaust as gas is being burned and turned
into mechanical energy to make the car functional. Figure one, below, shows not
only the differnces in CO2 emissions from standard fuel sorts, hybrid cars, and
diesel cars, but also forecasts the hopes of car manufacturers for future decreases in
enviornemntal impact.
Figure 1: The differences seen in CO2
emissions between vehicles burning standard
gas, diesel fuel, and hybrid cars, and their
predicted future rates of emission.
Not surprisingly, standard oil creates the most CO2, by emitting over 150g/km,
followed by diesel fuel at 120g/km. As could also be expected, the combination of an
electric car battery minimizes the amount of fuel required to cause a car to function,
decreasing its CO2 emission by nearly half. Figure 2 shows another research study
performed by Nansai et al. (2010), furthering the quantitative analysis of CO2
emissions between gasoline and electric vehicles.
Figure 2: Quantitative analysis showing CO2 emission rates between gasoline and electric vehicles
ranging from their production to consumption rates.
Although there are differing quantities of CO2 being emitted from cars, there
are many factors to consider before ranking them on severity of environmental
impacts. In addition to factors affected the outside environment, an arguably more
important assessment is the amount by which these burning chemicals lead to
human ailment and disease. According to Ahlvik and Brandberg (1999) in a
comprehensive review of the relative cancer potencies of particulates released from
car exhausts, diesel cars had a cancer risk index of 235, more than double the 100
listed from standard petrol cars. According to the Office of Environmental Health
Hazard Assessment, long-term exposure to diesel exhaust particles poses the
highest risk of cancer development of any air contaminant; this is in large part due
to the incredibly small size of the particles released when an engine burns diesel
fuel and infiltrates the lungs, leading to cancerous mutations of cells. Due to the
lessening of fuel being used in hybrid vehicles, it is not difficult to see the improved
health possibilities with a higher percentage of either hybrid or all electric vehicles
on the road.
To quote Uncle Ben when advising Peter Parker on his newfound skillset,
“With great power comes great responsibility.” This saying transcends the pages of
comic books and is directly applicable when discussing any innovation produced.
New technology brings about new problems, each of which needs to be properly
addressed; with regards to hybrid and electric vehicles, the innovation is easy to
see- more miles per gallon of gas decreases ones monthly bills, and the increase in
vehicle efficiency means we get to help save the planet and find alternate means of
transportation by not necessitating the usage of one of the earth’s rarest resources,
oil. The problem that can easily be overshadowed by these numerous benefits is the
exponential increase in the prevalence of Lithium-ion batteries, the key component
of hybrid vehicles.
Lithium-ion batteries contain three key elements that allow them to function,
an anode, a cathode, and a porous separator that allows the flow of particles
between the two. Figure 3 shows a graph created by Kohler et al. (2008) explaining
the process in which production must be taken in order to create the Lithium-ion
battery, from the beginning stages of manufacturing, to the actual packaging of the
final product.
Figure 3: Production stages of Lithium-ion batteries
Studies have been performed by the Environmental Protection Agency that show
environmental and health risks are at the highest when certain chemicals such as
nickel and cobalt are used as the cathode component of the battery. Nickel, in
particular, has seen a drastic increase in the necessary quantity being mined to
sustain its popularity as an integral role in rechargeable batteries. Typically, Nickel
is mined in two methods, one of which being substantially more environmental
friendly than the other. According to Mudd (2010), Nickel has historically been
mined from sulfide ores because of its more simplistic means and relatively clean
environmental outputs. With higher demands, Nickel has been recently mined more
from laterite ores, a process that has drastically increased both energy and
greenhouse gas emission costs. Similar to Nickel, Cobalt has the same complex and
environmentally impactful effects if mined in the high amount necessary to sustain
the demands of hybrid batteries. Dewulf et al. (2010), further exemplify this
problem by showing that in 2007, nearly 25% of the cobalt mined worldwide was
done so with the goal of creating these and similar types of batteries. In order to
maintain a environmentally conscious means of mass-producing Lithium-ion
batteries, I would suggest that these companies either innovate new ways to safely
and efficiently mine these elements without compromising the environment.
With 25% of the world’s cobalt being mined for the purposes of creating
parts essential for Lithium-ion batteries, a serious question that came to mind was
what kinds of health impacts could be present that affect these individuals that must
work in these mines. According to the United States Agency for Toxic Substances
and Disease Registry (2004), being exposed to cobalt for a significant period of time
can lead to the development of asthma, pneumonia and wheezing. In order to
categorize health impacts to certain populations, the Environmental Protection Act
has in place a formalized plan known as the Human Health Risk Assessment. This 4step outline sequentially determines the risks that we are exposed to and warrants
how severe they are. When it comes to analyzing the health risks associated with the
increased prevalence of hybrid cars, or specifically their Lithium-ion batteries, the
main health concern comes from the materials used. Since these materials are
mined, and able to be avoided if another way of production can be determined, the
EPA halts the Risk Assessment at Step 1, Hazard Identification. It could be in the
future that there are increased health risks with new technology that comes about,
but at this point in time the research shows that aside from the already potent
amount of greenhouse gases released into the air from car exhaust, the current
Human Health Risk Assessment is minimal.
One way that policy makers and engineers have decided to focus their efforts
to circumnavigate the problem of the higher exposure of individuals who work to
mine these increasing amounts of potentially dangerous chemicals is by using
different chemicals in the place of both nickel and cobalt when creating the cathode
for the Lithium-ion battery. Figure 4 shows the alternative chemicals that can be
used to create the Lithium battery to propel an electric vehicle; this graph created
by Notter et al. (2010), shows the use of manganese as a substitution for both Cobalt
and Nickel. By substituting the use of one chemical for another that is able to be
mined more efficiently, greenhouse gas effects could be minimalized as well, and
certain health risks to those who are instructed to do the mining could be decreased.
Figure 4: The amount of chemicals necessary that are currently being used to power an electric
vehicle for a distance of 1km.
Wellbeloved et al. (1997), furthered this evidence by citing that manganese
proves to be an excellent chemical replacement in rechargeable batteries due to a
low cost and ease of production, thermal safety, and most importantly, the fact that
manganese is abundant in nature and has been tested repeatedly in the battery
industry. In addition to this alternative method of using different chemicals to
achieve the same process in Lithium-ion batteries, scientists have researched the
implementation of carbon nanotubes at the anode to create a lighter and more
energetically favorable battery. While this plan was used for a short period of time,
it quickly became noticed that the lifetime of the nanotubes was short, and upon
degrading, would release harmful chemicals not only into the environment, but also
into those individuals nearby. Kohler et al. (2008) analyzed these results and
weighed heavily the eventual usage of carbon nanotubes in hybrid car batteries.
In addition to discussing the environmental implications of drastically
increasing the usages of certain chemicals, there are many other impacts that hybrid
car batteries can have on the planet, including global warming potential, and the
depletion potential of certain natural resources now in use for new manufacturing
practices. Notter et al. (2010) used these factors in creating Figure 5 to show the
differing environmental impacts between internal combustion engine vehicles
(ICEV) and electric battery vehicles (BEV).
Figure 5: A comparison between electric vehicles (BEV) and standard vehicles (ICEV) showing
differences in natural resource depletion potential (ADP), global warming potential (GWP),
cumulated energy demand (CED), and Ecoindicator (EI).
In each environmental impact comparison, the traditional vehicle relying on solely
gasoline for power provides a substantially higher risk as compared to electric or
hybrid vehicles. There are few who would argue that the environmental
implications of strictly driving a hybrid vehicle versus a standard internal
combustion engine are lower for the hybrid. In each comparison that Notter et al.
completed, hybrid vehicles appear to be more eco-friendly. Samaras and Meisterling
(2008), support the assertion of hybrid vehicles having less of an impact on the
planet by stating that when comparing one type of vehicle to another, there is a 32%
decrease in the amount of greenhouse gas emissions from hybrid vehicles.
One of the main concerns and needs for future generations to accomplish is
to find a way to support the manufacturing and distribution of hybrid cars in as
much of an environmentally friendly way as they are being driven. A concern seen
throughout many research papers is creating the infrastructure that can sustain
electricity supplies without simultaneously creating an enormous amount of
greenhouse gases. In 2001, Nansai et al. stated that although the environmental
impacts of developing the hybrid car charging infrastructure did not outweigh the
benefits seen by the decreased greenhouse gases emitted into the atmosphere, care
needs to be taken when determining how to proceed with this forging market.
Since the advent of electric vehicles is still a fairly new market,
comprehensive research on more thorough ways to improve gas mileage, decrease
costs of transportation, and most importantly, ways to decrease environmental
impacts are just beginning to emerge. Creating a sustainable, eco-friendly Lithiumion battery has been a major goal of engineers; and the work of Li et al. (2014) offers
some light into the proper materials that are to be used progressing forward. With
the goal of producing an efficient and environmentally friendly Lithium-ion battery,
they found that using silicon nanowires as the anode seems to be the material
producing the best results. Not only does this material produce promising results
when being driven, but this longitudinal study also showed that these nanowires
decrease global warming potential, and also can easily be produced in a sustainable
product manufacturing process in which the lifespan of these tools is substantially
long.
In addition to creating the most efficient Lithium-ion batteries possible, a key
direction for future research in this field is finding the highest efficacy ways of
recycling these batteries, a practice that will save consumers numerous costs in the
replacement of batteries, as well as minimizing our reliance on our world’s
dwindling natural resources. According to Dewulf et al. (2010), a meta-analysis
showing the potential benefits of recycling Lithium-ion batteries. They showed that
when these batteries that are being used to power hybrid vehicles were recycled to
their optimal abilities, it results in a 51% saving in the used natural resources.
Granovskii et al. (2006) performed an analysis looking across various fields
comparing both the economical and environmental impacts of hybrid cars versus
conventional vehicles. As asserted earlier, this research showed that environmental
impacts of the increased usage of hybrid cars largely depends not solely on the
decreased amount of exhaust emissions, but also on the conditions that the batteries
were created and the means of which the vehicles attained their electricity. This
paper showed that a hybrid vehicle becomes extremely advantageous over
conventional vehicles when the electricity that is being used is generated with
efficiency higher than 50% by the use of a turbine. Another point that is made
through this article discusses that there is a significant increase in advantage of
using hybrid vehicles when the electricity is generated on board, as is the case with
rechargeable Lithium-ion batteries.
Through this paper, both the pros and cons of hybrid vehicles have been
analyzed. The differences between CO2 and other greenhouse gas emissions have
been compared, highlighting results that show a drastic decrease in emissions from
diesel fuel to standard gas, and an even further decrease from standard gas to
electric vehicles. There have also been discussions about the potential pitfalls seen
in the mass production of hybrid vehicles, specifically the huge increase in Lithiumion batteries and the complex viewpoints about which chemicals will provide the
most efficient means of transportation while bringing about the least amount of
harm to both the driver and the environment. Perhaps one of the most important
factors that has been brought up in this review, and is arguably the portion most
actively discussed in politics and the economy, is the fear of draining this world of
its natural resources. By finding ways to decrease the current dependence on fossil
fuels through utilizing the Lithium-ion battery as the main form of transportation
throughout the world, and by continuing research into potential more efficient
methods of energy conductance between these batteries and the charging stations
of which they will rely, a substantial difference on environmental footprints can be
made.
References
Ahlvik, P. and Brandberg, A. Cancer risk index for passenger cars in India. Ecotraffic
Research and Development. 1999.
http://www.downtoearth.org.in/content/how-carcinogenic-yourcar?page=0,1, April 12, 2014
Cogan, S. Life cycle assessment highlights ways to reduce global warming emissions,
addresses nanotechnology innovations to improve battery performance. May
28, 2013.
http://www.abtassociates.com/newsreleases/2013/study-identifiesbenefits-and-potential-environmen.aspx, April 12, 2014.
Dewulf, J., Van der Vorst, G., Dentruck, K., Van Langenhove, H., Ghyoot, W., Tytgat, J.,
and Vandeputte, K. Recycling rechargeable lithium ion batteries: Critical
analysis of natural resource savings. Resources, Conservation, and Recycling.
2010; 2010: 229-235.
http://www.sciencedirect.com/science/article/pii/S0921344909001815,
April 11, 2014
Granovskii, M., Dincer, I., and Rosen, M. Economic and environmental comparison of
conventional, hybrid, electric and hydrogen fuel cell vehicles. Journal of
Power Sources. 2006; 159: 1186-1193.
http://www.sciencedirect.com/science/article/pii/S0378775305016502,
April 14, 2014.
Kohler, A., Som, C., Helland, A., and Gottschalk, F. Studying the potential release of
carbon nanotubes throughout the application life cycle. Journal of Cleaner
Production. 2008; 14: 927-937.
http://www.sciencedirect.com/science/article/pii/S0959652607001126,
April 12, 2014.
Li, B., Gao, W., Li, J., and Yuan, C. Life cycle environmental impact of high-capactiy
lithium ion battery with silicon nanowires anode for electric vehicles.
Environmental Science and Technology. 2014; 48: 3047-3055
http://pubs.acs.org/doi/abs/10.1021/es4037786, April 11, 2014
Mudd, G. Global trends and environmental issues in nickel mining: Sulfides versus
laterites. Ore Geology Reviews. 2010; 38: 9-26.
http://www.sciencedirect.com/science/article/pii/S0169136810000569,
April 11, 2014
Nansai, K., Tohno, S., Kono, M., Kasahara, M., and Moriguchi, Y. Life-cycle analysis of
charging infrastructure for electric vehicles. Applied Energy. 2001;70: 251265.
http://www.sciencedirect.com/science/article/pii/S0306261901000320,
April 11, 2014.
Notter, D., Gauch, M., Widmer, R., Wager, P., Stamp, A., Zah, R., and Althaus, H.
Contributions of Li-ion batteries to the environmental impact of electric
vehicles. Environmental Science and Technology. 2010; 44: 6550-6556.
http://pubs.acs.org/doi/full/10.1021/es903729a, April 11, 2014.
Samaras, C. and Meisterling, K. Life cycle assessment of greenhouse gas emissions
from plug-in hybrid vehicles: Implications for policy. Environmental Science
and Technology. 2008; 42: 3170-3176.
http://pubs.acs.org/doi/abs/10.1021/es702178s, April 11, 2014.
United States Environmental Protection Agency. Application of life-cycle assessment
to nanoscale technology: Lithium-ion batteries for electric vehicles.
http://www.epa.gov/dfe/pubs/projects/lbnp/final-li-ion-battery-lcareport.pdf, April 11, 2014.