Automotive Engineering - December 2023 - 31

SOLID STATE FEATURE
Toyota partner
Idemitsu's smallscale
solid-state
electrolyte plant.
has yet entered this procedure, though three have doubled down to
enter by the end of 2023. "
Benchmark projects of less than four gigawatt-hours of prototype
QuantumScape's
solid-state batteries will be produced in 2023 by the companies it is
tracking that are working on the technology. " To achieve anywhere
near mass-market penetration, manufacturing processes must be
scaled into the 100s of megawatt-hours, then to the many gigawatthours,
if emerging technologies want to compete on cost with the
incumbent li-ion batteries, " McNulty said.
Biden's IRA encouraging start-ups
The federal National Blueprint for Lithium Batteries 2021 to 2030 set
a goal of demonstrating, by 2030, the at-scale production of solidstate
batteries that are cobalt- and nickel-free and that meet a production
cost of less than $60 per kilowatt-hour, with a specific energy
of 500 watt-hours per kilogram.
Biden's Inflation Reduction Act also provides income tax credits for
EVs that, among other things, source their batteries in North
America. That's part of the picture for San Jose, California's
QuantumScape, which has a timetable similar to Toyota's and plans
to build its batteries in the U.S.
QuantumScape has succeeded in developing a flexible, non-crackprone
separator in a lightweight and compact cell design with a lithiummetal
anode that, in testing, has shown it can be recharged 1,000 times
(the equivalent of 300,000 miles in a 300-mile-range battery) while
using only " slightly more " lithium than standard li-ion cells, according to
QuantumScape chief technology officer and co-founder Tim Holme.
Holme told SAE Media that an auto OEM's evaluation of a 24-layer
prototype cell retained more than 95% discharge energy retention
after 1,000 full cycles. The company dispenses with conventional silicon
or graphite anodes. Instead, when the cell initially charges, lithium
ions plate on top of the solid-state ceramic separator, serving as
the pure lithium-metal anode after that.
The company also claims to have addressed the thorny problem of
" dendrites, " which are branch-type formations that can spread out
between the electrodes and cause short circuits. Dendrites are a particular
challenge in solid-state batteries.
In late 2022, QuantumScape showed 24-layer, A-Sample cells to
AUTOMOTIVE ENGINEERING
automakers. The company's higher-volume B-Samples
are expected to arrive in 2025 and could be evaluated
in customer test vehicles. C Sample, production-ready
cells qualified by the OEM customers will come after
that. " We're excited about developing and scaling our
solid-state batteries in the U.S., " said Asim Hussain,
QuantumScape's chief marketing officer. " And we're
encouraged by the federal tax credits available as we
build out the company. "
QuantumScape has funding from Volkswagen
Group and Bill Gates, and is also working with " two
established global luxury OEMs " and one " pure-play
EV company. " QuantumScape is also fighting a 2021
investor class-action securities suit alleging that it has
been misleading about its solid-state progress. U.S.
District Judge William H. Orrick denied a motion to
dismiss the case last year and QuantumScape doesn't
comment on pending litigation.
Colorado-based Solid Power, with Ford and BMW
as partners, has raised $700 million to date.
December 2023 31
24-layer prototype
solid-state cell.
FROM TOP: TOYOTA; QUANTUMSCAPE
Automotive Engineering - December 2023

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