US federal cash is on its way to fund research into long-duration energy storage using lead-acid batteries.

A consortium backed by industry bodies Battery Council International and the Consortium for Battery Innovation, will conduct pre-competitive research aimed at improving lead battery performance. Companies participating in the consortium include Advanced Battery Concepts, C&D/Trojan, Clarios, Crown Battery, East Penn Manufacturing, EnerSys, Gridtential and Stryten Energy. The collaborating national laboratories are Argonne, Oak Ridge and Pacific Northwest (PNNL).

The $5 million award from the US Department of Energy, announced on 27 September, will support work to develop lead batteries capable of 10+ hours of storage with a pathway to $0.05/kWh levelised cost of storage by 2030.

BCI’s technical director Tim Ellis, formerly technical director at battery company Ecobat, told BEST in an interview the three-year programme will combine advanced techno-economic analysis with fundamental materials science research.

“We have two technical issues we’re trying to work on,” he said. “One is cycle life, which is extremely important…The more cycles you get out of a battery, the less cost it is per unit, per kilowatt hour of storage. So we’re working on extending cycle life, and the other one that we’re working on is increasing the capacity utilisation of lead batteries. And we’re trying to get over 70% capacity utilisation at over 5,000 cycles. That’s the goal.”

PNNL will be doing the battery testing while the companies will be supplying it with products for testing. In a two-for-one funding arrangement, the companies will put $2.5 million into the research, Ellis said.

The research team is focusing on the technology rather than its application in systems. “We’re really working only on the technology. We’re going to let DOE and the power companies figure out the applications,” said Ellis.

Argonne, which has just undergone a $2 billion upgrade of its Advanced Photon Source (APS) at an existing $10 billion facility that no battery company could afford, will be doing modelling or measurement on the upgraded APS as the battery charges and discharges.

It will study the accumulation of various sulphates and oxides and check failure mechanisms within the battery, he said. As 5,000 cycles will take the battery past retirement, Argonne will build models to predict how long the batteries will cycle.

Crystallisation behaviour

A third element will work on fundamentals of crystallisation behaviour, to be done at Oak Ridge. The final section of the work is back at PNNL, and analysis of the batteries for failure. “We will look at how the materials have crystallised and dissolved. Then we go back and we develop new batteries and we retest them,” he said.

The information will then be used to build a techno-economic model by Vilayanur Viswanathan at PNNL for lead batteries in a specific long-duration energy storage space, Ellis said.

One of the challenges in the US is the long distances that need to be covered by power grids, sometimes across state boundaries. The Federal Energy Regulatory Commission is responsible for transfer of energy pricing between states and n0-one has worked out how to do that yet with LDES, according to Ellis.

The project is tasked with achieving LDES electricity pricing of $0.05/KWh. Ellis said things are close to $0.075/KWh. “So we’re getting there where that 5,000 cycles, that 70% depth of discharge comes in, is that’s kind of the minimum performance to hit five cents. Now, part of the problem with that number of five cents is they’re including the whole system.”

Battery manufacturers have no control over the cost of inverters, transformers or copper wire. Another problem, according to Ellis, is that no battery manufacturer makes systems. The larger the system, the more costs come down, he said. “There are very few massive scale lead systems. There’s a couple in China, but nobody’s built a 10MWh lead system in the United States, Europe or Japan. Not that I know of.”

He believes power companies in the US will be seeking systems of this size for grid storage, due to the size of the country. That would allow bus fleets, for example, to be charged at night after the batteries are charged up during the day.

The companies will have an equal share of the resulting IP, and can apply it to their own products, Ellis said. As this is pre-competitive research, each participating company will be free to decide how they use it and incorporate into their product lines. “The battery companies are not uniform. They all have their particular segmentations to market and capabilities. So some may do the same thing, other ones may do something completely different. One guy may do automotive with it.

“There’s nothing to prevent them from taking this technology and using it in automotive products or fork truck batteries or fishing motor batteries along with LDES.”

He added the reason BCI is promoting this research is the US government has put a huge investment into lithium batteries, and the country “has not prospered from it.”

Consumers have nice mobile phones and stuff, he said, but these research projects are for US entities only.

Ellis believes the project is significant. “Having the DOE recognise that lead technology is important to the continuation of growing the energy diversification economy is a big deal for our industry. You know, at least they’re not saying, go away, we don’t want to hear from you again.”