Shift Magazine - November 25, 2019 - 11

BATTERY
BASICS
Anode: A positively charged
electrode
Cathode: A negatively charged
electrode
Cell: An individual battery that is
part of a pack
Dendrite: A growth inside a
lithium battery, sort of like a
whisker, that can cause short
circuits. The growths can poke
through a battery's separator and
cause the battery to fail.
Electrolyte: The medium inside
a battery that enables ions to flow
between the positive and negative
electrodes. The electrolyte can be
liquid, solid or gel.
Electrode: Transports electrons
from one side of the battery to
another to produce electrical current
Energy density: The amount
of energy a battery can store in
relation to its size or mass. Density
determines the distance an electric
car can travel between charges.
Lithium: A highly reactive metal
inside the battery. Lithium ions
move from the negative electrode
to the positive electrode and back
again.
Pack: A group of individual batteries
connected in series. A Tesla Model
S with an 85-kilowatt-hour battery
pack has 7,104 individual cells.
Power density: The amount of
power a battery can store in relation
to its size. A battery with high
power density enables a vehicle to
accelerate very quickly but does not
help it go farther between charges.
Thermal runaway: When a cell in a
battery pack overheats and causes
other cells to overheat beyond
the ability of the vehicle's cooling
system, possibly leading to a fire.

decent amount of power. They may work
magic formula that enables an almost
for things like iPhones initially, but there
seamless transition from internal-combusare some big questions before
tion engines to electric motors.
+ The next
they are used in larger-scale sysResearchers know that to essenbig thing?
tems," he said.
tially replace gasoline the future
Page 12
General Motors is one of the
electric car battery - regardless
U.S. companies working on solid
of its chemistry - must:
state. During a Shift conference on batter* Have immense power and density
ies last month at Lawrence Technological
* Be capable of ultrafast recharging
University in suburban Detroit, Tim Grewe,
* Dramatically reduce the danger
director of GM's global electrification and
of fires
battery systems, said GM is bullish on sol* Last the life of the vehicle
id-state batteries.
* Cost far less than lithium ion does
"Solid state for me comes in two catetoday
gories - electrolyte and anode. Both of
* Affordably scale up to high-volume
them haven't earned their way in yet,"
production.
Grewe said during a panel discussion,
"but we are very encouraged with them,
"Certainly, the game has changed now,"
to say they offer better range and less
Joe LoGrasso, a director at the United
mass. They look very promising, and we
States Advanced Battery Consortium, told
are developing those as fast we can."
Shift. "The Koreans and Japanese have a
But GM, Toyota, Honda Motor Co., other
lot of development that looks promising.
automakers and battery suppliers are also
It's now a global race to get to the best
working on improving lithium ion batteries.
solution."
And while solid-state batteries have great
Solid-state batteries appear to have the
potential, Whittingham says there is still
best potential to meet most of the objecplenty of efficiency left to be gained by
tives for a next-generation battery, experts
improving the chemistry of lithium ion batsay. More lab work tweaking the chemistry
teries. "Right now, we only get 25 percent
and more real-world testing will determine
of theoretical capacity of them, so that's
whether they really do have the right stuff.
75 percent that's dead volume or dead
In an interview with Bloomberg pubweight," Whittingham
lished last month, M.
told Bloomberg. "It's
Stanley Whittingham,
the top folks in the
one of the three men
world working on that
awarded this year's
project."
Nobel Prize in chemLoGrasso said: "As
istry for their work on
we look at the next
lithium ion, acknowlgeneration of lithium
edged the potential of
ion batteries, they are
solid-state batteries but
going to include more
said he expects lithium
nickel content in the
ion to remain dominant Solid-state batteries, such as this
one from Toyota, use solid electrolyte
positive
electrode.
for at least the next
rather than a liquid or gel.
We'll start adding
decade.
more silicon to deal with fast-charging
"Toyota Motor Corp. and a whole host
in the negative electrode. There is a lot
of American companies are working on
of research going on into less flammable
solid-state batteries, though it's not clear
electrolytes to try to deal with the flamhow much those will cost to manufacture,
mability threat." n
and it's not clear yet whether you'll get a
november 2019 * shift

11
Shift Magazine - November 25, 2019

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