Insight: Austin, we have a problem! Tesla descends into battery hell

Panasonic Holdings

21/12/2023 11:00

By Norihiko Shirouzu, Paul Lienert
       AUSTIN, Texas, Dec 21 (Reuters) - Elon Musk says
prototypes are easy, production is hell. And when it comes to
the long-awaited Cybertruck, Tesla's hell is its pioneering 4680
battery.
Tesla delivered the first of its futuristic stainless
steel-plated electric pickups last month and CEO Musk said in
October that it would probably hit an annual production rate of
a quarter of a million vehicles at some point during 2025.
    But Tesla is still a long way off that kind of production
pace, and one of the main bottlenecks is the speed it can make
the 4680 batteries used in the Cybertruck with its new
dry-coating technology, nine people familiar with the matter
said.
    Tesla's Giga Texas factory is currently churning out 4680
battery cells at rate only sufficient to power about 24,000
Cybertrucks a year, or about a 10th of the required output,
according to Reuters calculations based on a combination of
public data and unpublished figures provided by sources.
Being able to ramp up battery output massively by dry-coating
electrodes - rather than using the slower, more costly
wet-coating - was a key factor behind Tesla's forecasts in 2020
that it would more than halve battery costs, cut investment
significantly, and create smaller, greener factories.
    The nine people, who spoke to Reuters on condition of
anonymity because of the sensitivity of the matter, said Tesla
had yet to crack dry-coating at the industrial scale needed to
make 4680 batteries fast enough to hit its production targets.
    The people said dry-coating the anode in the 4680 cells was
not problematic but Tesla was struggling with the same technique
for the cathode - the most expensive component in a battery.
    Dry-coating anodes and cathodes is proven in the laboratory,
as well as for smaller energy storage devices such as super
capacitors, and even some small batteries, according to Yuan
Gao, a battery technology consultant.
    "But no one has done it so far for large EV batteries at a
mass scale and at a high enough speed. Tesla is the first one to
try to commercialize this," said Gao, who has worked in the
industry for three decades.
    "The challenge is that not only does Tesla have to scale it
up and speed up the process, it also must develop its own
equipment and tools. It's daunting to say the least," he said.
    Tesla did not respond to detailed questions from Reuters for
this story.
     
    CRACKING THE CODE
    According to three of the sources, the 4680 batteries in
Cybertrucks include an estimated 1,360 individual cells.
    That means Tesla would need to make 340 million cells a
year, or almost a million a day, to supply 250,000 of the
electric pickups, which are entering a hot market with rivals
such as Ford's  F.N  F-150 Lightning, Rivian's  RIVN.O  R1T and
an electric Hummer from General Motors  GM.N .
    At the moment, Tesla's Austin factory takes about 16 weeks
to make 10 million 4680 cells, according to Reuters calculations
based on figures from Tesla, verified by the three sources.
    That translates to 32.5 million cells a year, or enough for
just under 24,000 pickups - and that's only for the Cybertruck.
    Tesla also wants to use 4680 batteries to power other
vehicles, most notably the $25,000 small car the company is
scrambling to launch by the mid-2020s.
Tesla has some limited production capacity for 4680 cells in
Fremont, California but its plant there is mainly for pilot
production. Panasonic  6752.T , one of Tesla's long-standing
battery suppliers, is planning to build at least two plants in
the United States but has only just broken ground on the first.
    Two of the nine people familiar with the matter believe
Tesla's progress with scaling up 4680 production will likely
gain steam, especially once it achieves stability with the
production know-how on one production line.
    They said Tesla had been focusing on establishing robust
know-how to produce batteries without flaws first time round.
It's a time-consuming process but, "once you crack the code and
establish stability, it is like exponential", one of them said.
    "Speed would pick up. There is already a lot of traction in
dry coating," the person said.
    Tesla's battery tsar Drew Baglino said in October that the
company was now producing 4680 cells on two production lines in
Austin and plans to install a total of eight lines there in two
phases, with the last four due to be running in late 2024.
    Still, one of the two people said replicating established
know-how from one production line to the next is no cakewalk.
    The source said only about 5% of cells made on profitable
production lines are ditched but scrap rates could shoot up to
30%-50% and hover there for several months as each new line gets
going.
    One of the sources said Tesla's dry-coating method for
cathodes was not proving to be any faster than the old wet
process, though scrap rates had dropped to as low as 10% to 20%.
    Baglino did not respond to requests for comment for this
story.
     
    'GOOEY MESS'
    The sources said Tesla was struggling to mix the cathode
materials, which include lithium, manganese and nickel, with a
binder and stick them to a metallic foil to produce a cathode -
without using moisture.
    Two of the people said the process worked for small amounts
but when Tesla tried to scale it up, a lot of heat was generated
and this melted the binder, which one of the sources believed
was polytetrafluoroethylene, more commonly known as Teflon.
    "If you melt the glue, pretty soon everything will become
one big chunk of gooey mess," another of the sources said.
    Equally problematic for Tesla are the machines used to coat
the metallic foil to produce battery electrodes - equipment
which is akin to huge magazine and newspaper printing machines
with large rollers, the sources said.
    To accelerate cell production, Tesla is trying to coat
multiple strips of magnetic foil with active battery materials
at the same time, and at high speeds.
    That calls for large, wide rollers, as well as applying
tremendous force to press the materials onto the foil. But
because the rollers are large and wide, applying pressure evenly
is proving to be a challenge, the sources said. 
    And when pressure is not applied evenly, Tesla gets
electrodes with uneven surfaces and thickness, which are no use
for its battery cells and need to be scrapped, the sources said.
    Perhaps more problematic, Tesla's Baglino told a fireside
chat at a battery conference in March that Tesla was still
building a completely new quality verification system so they
could weed out cells with flaws in coating.
    One of the sources with knowledge of the matter, said
specifically it was about building data infrastructure around
Tesla's battery development, manufacturing and in-field use
because in some cases the flaws were hidden in the coating
and did not show up for a few months down the road.
    In other words, Tesla doesn't quite know yet which dry cells
are good, and which ones need to be junked, the source said.

    <^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Starting at $60,990, Tesla's Cybertruck is priced 50% higher
than initial estimate     ID:nL4N3CV472 
Tesla Cybertruck's stiff structure, sharp design raise safety
concerns -experts     ID:nL1N3D32DY 
FACTBOX-Tesla's Cybertruck - top features and specifications   
 ID:nL4N3CV4JQ 
Panasonic plans multiple new battery factories in North America
by 2030     ID:nL1N37F0EO 
INSIGHT-Inside Tesla's drive to keep Musk's battery promise    https://www.reuters.com/business/autos-transportation/inside-teslas-drive-keep-musks-battery-promise-2022-09-06/
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^>
(Reporting by Norihiko Shirouzu in Austin and Paul Lienert in
Detroit; Editing by David Clarke)
((norihiko.shirouzu@thomsonreuters.com))