Passage 1 is excerpted from Michael Thackeray’s“ The Long, Winding Road to Advanced Batteries for Electric Cars,” published in 2012. Passage 2 is excerpted from Julie Chao’s “Goodbye, Range Anxiety? Electric Vehicles May Be More Useful Than Previously Thought,” published in 2015.
Passage 1
Batteries have come a long way since Alessandro Volta
first discovered in 1800 that two unlike metals, when
separated by an acidic solution, could produce an electric
current. In their evolution, batteries have taken on various
forms, ranging from lead-acid, to nickel-metal hydride, to
current-day lithium-ion.
Now, technological advances in batteries are more critical
than ever. Coupled with the alarming rate at which we are
exploiting fossil fuels, the world’ growing energy demand
necessitates that we find alternative energy sources.
With present-day technology, however, electric vehicles
cannot compete with internal combustion vehicles.
According to [one] review, “energy densities two and five
times greater are required to meet the performance goals of a
future generation of plug-in hybrid-electric vehicles (PHEVs)
with a 40-80 mile all-electric range, and all-electric vehicles
(EVs) with a 300-400 mile range, respectively.” To make the
leap, scientists will have to find new couplings of battery
materials.
Still, researchers are hopeful of a breakthrough. They can
now use computing to accelerate the discovery of new
electrode and electrolyte systems. This creates a positive
feedback loop in which computing informs experiments, and
experimental results help refine the computing process. This
high-throughput iterative process may be scientists’ ultimate
hope for discovering materials that can significantly improve
the electrochemical performance, safety and cost of batteries.
Passage 2
With today’s electric vehicle (EV) batteries, “end of life”
is commonly defined as when the storage capacity drops
down to 70 to 80 percent of the original capacity. As capacity
fades, the vehicle’s range decreases. Berkeley researchers
decided to investigate the extent to which vehicles still meet
the needs of drivers beyond this common battery retirement
threshold.
The Berkeley scientists analyzed power capacity fade, or
the declining ability of the battery to deliver power, such as
when accelerating on a freeway onramp, as it ages. They
modeled the impact of power fade on a vehicle’s ability to
accelerate as well as to climb steep hills and complete other
drive cycles. They found that power fade for the chosen
vehicle [a Nissan Leaf] does not have a significant impact on
an EV’s performance, and that a battery’s retirement will be
driven by energy capacity fade rather than by power fade.
The researchers thus’ conclude that “range anxiety may be
an over-stated concern” since EVs can meet the daily travel
needs of more than 85 percent of U.S. drivers even after losing
20 percent of their originally rated battery capacity. They also
conclude that batteries can “satisfy daily mobility requirements
for the full lifetime of an electric vehicle.”
Passage 1
Batteries have come a long way since Alessandro Volta
first discovered in 1800 that two unlike metals, when
separated by an acidic solution, could produce an electric
current. In their evolution, batteries have taken on various
forms, ranging from lead-acid, to nickel-metal hydride, to
current-day lithium-ion.
Now, technological advances in batteries are more critical
than ever. Coupled with the alarming rate at which we are
exploiting fossil fuels, the world’ growing energy demand
necessitates that we find alternative energy sources.
With present-day technology, however, electric vehicles
cannot compete with internal combustion vehicles.
According to [one] review, “energy densities two and five
times greater are required to meet the performance goals of a
future generation of plug-in hybrid-electric vehicles (PHEVs)
with a 40-80 mile all-electric range, and all-electric vehicles
(EVs) with a 300-400 mile range, respectively.” To make the
leap, scientists will have to find new couplings of battery
materials.
Still, researchers are hopeful of a breakthrough. They can
now use computing to accelerate the discovery of new
electrode and electrolyte systems. This creates a positive
feedback loop in which computing informs experiments, and
experimental results help refine the computing process. This
high-throughput iterative process may be scientists’ ultimate
hope for discovering materials that can significantly improve
the electrochemical performance, safety and cost of batteries.
Passage 2
With today’s electric vehicle (EV) batteries, “end of life”
is commonly defined as when the storage capacity drops
down to 70 to 80 percent of the original capacity. As capacity
fades, the vehicle’s range decreases. Berkeley researchers
decided to investigate the extent to which vehicles still meet
the needs of drivers beyond this common battery retirement
threshold.
The Berkeley scientists analyzed power capacity fade, or
the declining ability of the battery to deliver power, such as
when accelerating on a freeway onramp, as it ages. They
modeled the impact of power fade on a vehicle’s ability to
accelerate as well as to climb steep hills and complete other
drive cycles. They found that power fade for the chosen
vehicle [a Nissan Leaf] does not have a significant impact on
an EV’s performance, and that a battery’s retirement will be
driven by energy capacity fade rather than by power fade.
The researchers thus’ conclude that “range anxiety may be
an over-stated concern” since EVs can meet the daily travel
needs of more than 85 percent of U.S. drivers even after losing
20 percent of their originally rated battery capacity. They also
conclude that batteries can “satisfy daily mobility requirements
for the full lifetime of an electric vehicle.”