Why are lithium-ion batteries getting cheaper?

Like solar panels and wind turbines, the price of lithium-ion batteries has plummeted over this century, with a study from March estimating that cost has dropped by 97% worldwide since their introduction in 1991.

Now, the same team of researchers have sought to explain why the price has fallen so much. Publishing their results in Energy and Environmental Science, they say that research and development (R&D), particularly in chemistry and materials science, has been the major factor in dropping the price of the batteries.

The researchers, who are based at the Massachusetts Institute of Technology, US, examined a range of different financial and scientific documents from the past 30 years.

“The data collection effort was extensive,” says co-author Dr Micah Ziegler.

“We looked at academic articles, industry and government reports, press releases, and specification sheets. We even looked at some legal filings that came out. We had to piece together data from many different sources to get a sense of what was happening.”

In total, according to Ziegler, the researchers collected “about 15,000 qualitative and quantitative data points, across 1000 individual records from approximately 280 references”.

The researchers have previously used this method to examine the dropping price of solar cells and rising costs of nuclear energy.

Read more: Long live the power of lithium-ion batteries!

“We estimate that the majority of the cost decline, more than 50 percent, came from research-and-development-related activities,” says co-author Professor Jessika Trancik. Private-sector and government-funded research both contributed to this decline.

The research helped improve a range of different parts of the lithium-ion landscape, including manufacturing systems, supply chains, and the designs of the batteries themselves.

“The cost improvement emerged from a diverse set of efforts and many people, and not from the work of only a few individuals,” says Trancik.

“The R&D contribution didn’t end when commercialisation began. In fact, it was still the biggest contributor to cost reduction,” adds Ziegler.

The researchers say that there’s still much to be improved in lithium-ion batteries; this paper could help to provide direction for the next places to invest.

“What are all the things that different decision makers could do?” asks Trancik.

“What decisions do they have agency over so that they could improve the technology? [This is] important in the case of low-carbon technologies, where we’re looking for solutions to climate change and we have limited time and limited resources.

“The new approach allows us to potentially be a bit more intentional about where we make those investments of time and money.”

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