New Technology May Help EV Batteries Charge Faster, Last Longer

NREL’s process, named BatMan, uses lasers to create small pores in electrodes

February 27, 2024


Scientists at the U.S. National Renewable Energy Laboratory (NREL) have developed a new manufacturing process called BatMan that could improve electric vehicle (EV) batteries by making them charge faster and drive further.

The new technology uses lasers to create small pore networks in battery electrodes. This allows ions to move through the battery more quickly during charging and discharging, resulting in faster charge times.

The number of EVs is set to exceed 100 million by 2026 and reach 700 million by 2040, from only 27 million at the beginning of 2023. A sharp decline in prices of lithium-ion batteries made EVs more affordable as manufacturers slashed prices to pass down cost-savings to customers.

The addition of millions of EVs on the roads will pressure charging networks and increase “range anxiety,” necessitating the need for batteries that charge quickly.

But which pore patterns yield the greatest benefits? The researchers, using advanced 3D modeling, found that a hexagonal pattern of pores with a depth of 50% of the electrode coating thickness yielded the best results.

The pores were then created using high-speed lasers developed by the company Amplitude Laser Group. “Our collaboration with NREL helped integrate the laser into their existing research capabilities to support the BatMan project goals,” said Quentin Mocaer, line manager at Amplitude Laser.

The study also found that adding straight channels across the width of the electrode dramatically improved electrode ’wetting’ when compared to unstructured electrodes.

Wetting is the process of getting electrolyte fluid into the battery. The electrode can be like a dry sponge, where the liquid electrolyte must spread and absorb evenly. Inadequate wetting can hinder the movement of ions, resulting in slower charging, lower energy density, and decreased battery efficiency.

Better wetting leads to higher performance and longer battery life.

Early tests by battery manufacturer Clarios showed that the electrodes wet faster and more uniformly with the laser patterning, demonstrating superior fast-charge performance, with nearly 100% more capacity after 800 cycles.

Using a roll-to-roll manufacturing line, which bonds the active material mixture onto a foil surface and is used in most battery manufacturing facilities, the scientists successfully produced over 700 meters of laser-patterned electrode material. This demonstrated that the technique can be scaled up for mass production in battery factories.

Researchers also found that laser-patterning adds less than 2% to battery costs but could double charge rates, making EVs much more practical for everyday use.