What does the lithium battery material that accounts for the company's revenue share mainly refer to? Aren't lithium battery materials mainly purchased? Why are they sold to others?

CATL: Dear investors, the company can process, purify, synthesize and produce ternary precursors, lithium carbonate and other battery materials from nickel, cobalt, manganese and lithium metal materials and other materials in waste batteries, and sell the collected copper, aluminum and other metal materials to the outside world, so as to realize the recycling of the above materials. Thank you for your attention.