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ALTERNATIVE BATTERY TECHNOLOGIES

Real world applications
The high operating temperatures and “Our long term vision has always been to target grid
liquid constituents mean that the tech-
nology is not suited to mobile applica- scale applications. Lithium ion could move from its
tions. But its system-level energy den- regular use in 15-minute, frequency regulation to
sity of a 1MWh system in a 10 foot
ISO shipping container makes it com- longer duration services, and you’re already seeing
parable to lithium ion batteries and this at some levels, but there’s the question of cost.”
better than lead acid batteries.
The technology’s niche lies in sta-
tionary applications that regularly So close, in fact, it says they were with a product that can scale to be the
require daily, full depth of discharge, set to ramp up production and were lowest cost product in the market-
four to eight-hour duration services. preparing to deploy their battery into place.” He says the technology is scal-
The focus of Ambri is on multiple the field when they decided instead to able up to tens or hundreds of mega-
hour, charge and discharge services, modify the cell design and chemistry watt-hours. The key will be if, and
which lends itself to the peak demand amid falling lithium ion prices. when, liquid metal can make the jump
and peak shifting markets. The company says it is building to- from kWh laboratory testing to MWh
“This can be on the grid at the right wards commercializing its cells in the field-ready storage system.
price point as more renewables are in- next two years, when it will start de-
tegrated onto the grid,” says Bradwell. ploying systems. CYCLES AND LIFETIMES
“We see the need for peak-shifting “When we started at MIT we want-
batteries increasing significantly over ed to invent a technology that could Bradwell says the chemistry
the next 10 or more years, and there meet a price point and not just invent has demonstrated more than
is growing demand for this sort of a a nice new technology,” says Bradwell. 4,000 cycles under accelerated
battery. “Lithium ion prices have dropped conditions, with no degradation.
“Our long term vision has always since we started Ambri, so we have Some early cells have operated
been to target grid scale applications. had to pivot a few times to stay be- for thousands of cycles after more
Lithium ion could move from its regu- low future cost projections, and we than four years of continuous
lar use in 15-minute, frequency regu- feel good about the cost opportunity operation, and continue to run
lation to longer duration services, and against even optimistic future lithium today.
you’re already seeing this at some lev- ion cost projections. So how many years does it take
els, but there’s the question of cost. “But we decided to not discuss cost until the battery reaches 80% of
“Economies of scale may lessen the projections because we are still in de- its initial capacity — a standard
weight of that argument, but the per- velopment mode, and until the prod- metric for specifying the lifespan of
ceived shortcoming in the materials uct is finalized, things can change. We a battery?
supply chain in the next five years will didn’t want to add to the noise of the “Looking at our data, if we
be a much bigger hurdle for the chem- marketplace as just one more aspi- assume one cycle per day, the
istry to navigate. rational vendor that is excited about data extrapolates to suggest that
“Multiple hour duration storage is the potential of their pre-commercial our cell chemistry could last for
where the market is going. We strad- technology and is not yet at scaled 360 years,” says Bradwell.
dle the long and short duration mar- manufacturing. “ Of course, we don’t think
kets. Lithium ion is coming down in “Plus, as a start-up company, we our system will last for that long
cost and shifting from the higher pow- need to be able to price to the market, because something other than
er to higher energy applications. How- not our costs.” the electrodes or electrolyte will
ever, one of the key advantages com- Bradwell, however, does disclose the degrade, but the fundamentals
pared to many other emerging battery capital required for a factory mak- of the chemistry are extremely
technologies is that we are pretty close ing their liquid metal batteries at a stable, and this could allow for an
to the energy density and footprint of gigawatt-hour scale. He puts the price extremely long lifespan system.
lithium ion systems. of a new factory at around $30 to “We are targeting a 10 to 20 year
“But we’ve got a technology that’s $40 million, equipment, cap-ex, and lifespan, but we may ultimately
very low cost, and has a very long life building upgrades included. Compare find that the technology can last
span.” that with some lithium gigafactories, for many decades. We haven’t
which have reasonable economics, but demonstrated this yet, but the
Low cost gigawatt plant require billions of dollars of invest- chemistry doesn’t seem to
On paper, a technology that can strad- ment to achieve. degrade, which is very different
dle application services, offers long “Our factory cost is very low and we from other batteries.
cycle life, is made from abundant ma- still achieve high volume scaled manu- “Other chemistries suffer,
terials and is safe sounds like the ideal facturing costs for a relatively small particularly due to irreversible
energy storage solution. capital requirement,” he says. reactions between the electrolyte
But those descriptions can be ap- So how close is Ambri to entering and the electrodes, but common
plied to flow batteries, and the for- the battery market? degradation mechanisms like this
tunes of companies in that market “We’re still in the development simply aren’t active in our cell
are at best fluctuating, with some big mode,” says Bradwell, “but when we chemistry, so it doesn’t degrade in
names in the sector folding. The driver do enter the market we are targeting the same way as, say, lithium ion
for adoption is cost, and Ambri has systems that are housed in 10 foot or lead acid.”
been tracking prices closely. shipping containers at the 1MWh size,

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