RÜCKGEWINNUNG VON MATERIAL AUS BESCHICHTETEN SUBSTRATEN

摘要

Methods are presented for reclaiming active material used in formation of secondary electrochemical cells and similar electrodes. Active materials such as nickel-metal hydride are removed from cell electrodes together with the binders used to secure the active materials to the electrode substrates. Because the binders and other agents are recovered without loss or degradation, the active materials may be easily and simply reconstituted and reused to form new electrodes. The methods are particularly applicable to electrodes fabricated by deposition of active material on flexible conductive substrates. The reclamation methods include mechanical separation, such as bending and ultrasonic beating, to remove the active materials without adding other chemical agents. The removed active materials are ground and sized. Solvent is added to dissolve binders and form a reconstituted active material paste. This paste may then be introduced to an electrode fabrication process in combination with, or in replace of, virgin paste. Devices are presented for the effective mechanical separation of active material from electrode substrates. One embodiment of these devices includes a pair of bending wheels which bend the electrodes repeatedly into a rough wave form. By bending the electrode repeatedly at adjacent locations, substantially all the active material and other constituents may be recovered. Bending at an angle smaller than a determined critical angle is required for effective separation and recovery.