As stated this refers to an historic abuse, and not related to ESS or EV's but all the same interesting after we saw a similar cartel exposed in Europe last year for industrial batteries, including Exide and Hoppecke.
With prices plummeting for Li-ion batteries for ESS and EV applications it's hard to see a cartel situation here, but I'm sure it would be tempting. The race to the bottom (pricing) we see presently is a dangerous game for all involved.
Relating more to rechargeable batteries of the type found in consumer electronic goods such as laptops and mobile phones rather than EVs or stationary storage, the charges relate nonetheless to both cylindrical and prismatic cells, as found in some stationary storage products. All four makers breached EU antitrust rules when they agreed on temporary price increases in reaction to a rise in the price of cobalt used in lithium-ion batteries and also exchanged commercially sensitive information with each other. This included price and demand forecasts. The manufacturers struck up bilateral or sometimes multilateral agreements in Asia for the most part as well as in Europe.