A new formation process developed by Cornell engineers and a battery maker could cut lithium-ion battery production time by up to 60 per cent.
A lithium-ion battery is not ready for use as soon as it is assembled. It must first go through several charging and discharging cycles in a process called formation. According to researchers at Cornell University, this stage accounts for roughly a third of the cost of making a cell. A Cornell team working with Charge CCCV (C4V), a battery company based in Binghamton, New York, now reports that it has reduced formation time by up to about 60 per cent in testing.
The layers formed through these early cycles are very thin and help protect the electrodes from the liquid electrolyte. These layers help determine the life span of the battery. However, manufacturers cannot directly observe how the layers develop during formation. “Evaluating formation processes is typically very trial and error,” said Vibha Kalra, the Cornell chemical engineering professor who led the work. Assessing the long-term effects can take months or even years, as cells must undergo thousands of charging and discharging cycles.
The team used two measurement techniques to study the cells during formation. Raman spectroscopy, which analyses scattered laser light, revealed the chemical composition of the protective layers at the electrode surfaces. Impedance spectroscopy, which measures electrical resistance, showed how these layers affected the cells’ electrical behaviour. The researchers found that slower charging produced more uniform layers rich in inorganic compounds, while key resistance measurements stabilised after about 1.5 cycles. They also found that discharging might be accelerated. Using these observations, the team developed two faster formation routines.
Compared with C4V’s conventional process, the new routines maintained comparable battery performance while reducing formation time by up to about 60 per cent. The improvement could be significant for manufacturers because formation also accounts for around a quarter of factory floor space and a quarter of a battery plant’s electricity use. Shalabh Gupta, C4V’s system engineering manager, estimates that overall power consumption could fall by 10 to 15 per cent. He also estimates that a factory producing more than 10 gigawatt-hours (GWh) of cells annually could save up to $100 million in formation costs.
These figures are the company’s estimates rather than results from an independent cost analysis, and they relate to large-scale manufacturing. The Cornell announcement does not specify how long the formation process takes before and after the change. It also identifies the cells only as lithium-ion batteries, without specifying their chemistry.
The protocols were tested on battery materials at C4V’s facility in Binghamton, taking the work beyond a laboratory-only demonstration. However, the announcement does not confirm that any factory has adopted the new routines. Faster discharging is also described as a possibility rather than a demonstrated outcome. The findings were published in Energy Storage Materials, and the research was funded through the US National Science Foundation’s Energy Storage Engine in Upstate New York.
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