How Solid State Batteries Work and How They Would Change Electric Cars
The electric car industry has
grown dramatically in recent years and appears poised to continue
this expansion. Sentiment is reflected in Tesla’s spectacular stock
performance and the urgency with which CEOs have sought to capture
value from the EV market, even plunging headlong into
controversial deals
with Nikola. There’s also been a
proliferation of ways that the average consumer can
participate, such
as buying “slices” of pricey EV-related stocks or using gamified
apps like Robinhood to follow the herd and profit from momentum. Motortrend reports that the
global next-generation battery market will grow from nearly $40
million in 2021 to over $400 million in 2025. Meanwhile, 2019 saw
about
7.2 million
electric vehicles (EVs) on the road globally. Over the next 10
years, experts estimate the number will approach 140 million. This growing boom in the EV
market has created a similarly burgeoning demand for batteries that
are increasingly stronger, more durable, and longer-lasting.
Lithium-ion batteries have been intrinsic to this rising success,
offering unique benefits that include longer service lives and
higher energy densities. The emergence of “green”
lithium mining rivals boasting an ability to produce battery-grade
lithium
without the byproduct of carbon dioxide
is gaining attention. So is the declining price of lithium-ion
batteries: prices have declined
by almost 90% over
the last decade. However, these batteries also
pose many challenges. Lithium-ion batteries are
inefficient. A big problem is that they offer only a limited driving
range on a single charge. Further, the charging time is longer than
most drivers find reasonable. The impact of this flaw only increases
in magnitude as consumer demands from their vehicles and the needs
of the EV industry to accommodate continue to evolve. How Electric
Batteries Work
What primarily distinguishes
EVs from standard gasoline-powered vehicles is that EVs contain an
electric-traction motor in place of the internal-combustion engine
that runs gas-powered vehicles. Every EV contains a traction battery
pack that it uses to store the energy it requires to operate. This battery pack is what EV
operators must plug into charging stations periodically in order to
keep their vehicles powered. The efficiency of the battery used is a
key determinant of the vehicle's range and performance and,
therefore, of its viability with consumers. There are four types of
batteries most commonly used in EVs:
●
Lithium-ion
●
Nickel-metal hydride
●
Lead-acid
●
Ultracapacitors. Nickel-metal hydride batteries
and ultracapacitors are inexpensive but offer too short of a life
cycle for practical use, while nickel-metal hydrides and lead-acid
batteries offer too narrow of a temperature-range for optimum
performance. By contrast, lithium-ion batteries excel in all of
these areas, as well as offering a decent weight and
energy-efficiency. For this reason, lithium-ion batteries have
become, by far, the most commonly used batteries in EVs. Unfortunately for the EV
industry, however, one of the biggest concerns consumers have with
adopting EVs over the standard internal-combustion-engine vehicles
is the periodic reports of lithium-ion batteries exploding in EVs.
What causes this potential flammability are the liquid organic
electrolytes (LEs) used in most lithium-ion batteries. There are other issues,
however. Efforts to improve lithium-ion batteries to meet the
growing needs of EVs to compete with the power and performance of
internal-combustion engines have only increased the array of
challenges they pose. How Solid-state
Batteries Work and What Makes Them Different Than Other Batteries
Solid-state batteries, also
known as all-solid-state batteries (ASSBs,) substitute solid
electrolytes (SEs) for LEs. This makes them nonflammable and,
therefore, a promising substitute for lithium-ion batteries in EVs. Solid-state batteries also have
a wider operating temperature than lithium-ion batteries, making
them perform more stably in different conditions. The solid-to-solid
contact between the lithium metal and the electrolyte also reduces
the risk of lithium dendrites, one of the major causes of safety
concern with EVs. By creating a solid physical
barrier between cathodes and anodes, solid-state batteries allow for
bipolar electrode configurations that can better optimize energy
density. This allows them to make better use of limited space,
facilitating smaller battery casings and, thereby, making EVs
lighter, faster, cheaper, and more efficient. Recent Advances in
Electric Batteries
Recently, Toyota Motor Company
announced a
prototype of a
solid-state battery that could revolutionize the EV industry. It is
estimated to yield a range of 300 miles with a charging time of only
about 10 minutes. With no hulking heating and cooling system to
maintain, this upcoming Toyota solid-state battery prototype is
promised to retain 80% of its capacity for about 240,000 miles, or
800 cycles. Additionally, it won’t be prone to spontaneous
combustion. In its December 2020 announcement of the prototype,
Toyota said it should be ready to unveil before the end of 2021. As charging time and range are
the two largest obstacles to the public at large, this new
technology could be a game-changer. Motortrend likens this
innovation to an electric starter for EVs and says it would finally
subvert the remaining advantages of internal-combustion engines. Toyota has also recently
announced an
electric SUV soon
to be released in the European auto market. With over 1,000 patents
already for solid-state battery technology alone, Toyota estimates
it will start installing solid-state batteries in its new vehicles
in production by 2025. Nissan, meanwhile, is also
developing a
solid-state battery
that, by 2028, the company estimates it will start installing in
what it calls a “non-simulation vehicle.” Another company, QuantumScape,
in California, has partnered strategically with Volkswagen to create
its own solid-state battery cell. As of the new year, this project,
too, has yielded encouraging progress. Samsung is working on a
solid-state battery using carbon rather than lithium, promising a
potential range of 500 miles per cycle while taking up half the
space of a lithium-ion battery of today. Other major car companies
jumping into the electric battery game include BMW, Ford, and
Mercedes. Why Electric
Batteries Matter
Nissan and Toyota are both
Japanese companies clearly benefiting from that government’s fund of
approximately
$19 billion (2 trillion yuan) to aid in the
development of decarbonization technology, including, in large part,
solid-state battery technology. This illustrates at least one
country’s recognition of the relevance of the link between climate
change and internal combustion engines, between reducing harmful
carbon in the atmosphere and electric-battery technology. Meanwhile,
two major Japanese oil and mining companies are now working to
produce solid electrolyte. Becoming More
Mainstream
Broadly, consumers recognize
the benefit of EVs over internal-combustion vehicles when it comes
to the environment. But they're still not quite ready to adopt the
technology en-masse due to remaining technological limitations. With
the advent of solid-state batteries, however, that widespread
perspective may be about to change. In all, solid-state batteries
will make EVs more accessible to the mainstream consumer auto
marketplace by reducing the cost to build, and therefore the cost to
sell, electric vehicles while vastly improving their efficiency
through faster charging times and their safety by eliminating
flammable liquids from the system.
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