LiCoO2 was subjected to co-grinding with PVC using a planetary ball trill to form Co- and Li-chlorides mechanochemically in the product. Subsequently, the ground product was dispersed in water to extract the chlorides. The grinding facilitate, mechanochemical (MC) reaction, and the extraction yields of both Co and Li are improved as the grinding progresses. The 30-min grinding enables us to reach over 90% for Co and nearly 100% for Li. Accordingly, about 90% of chlorine in the PVC sample has been transformed into the inorganic chlorides by the time. This would be an effective method for recovering Co and Li from lithium-ion secondary (LIS) battery wastes. (C) 2004 Elsevier B.V. All rights reserved.