New regeneration process for spent nickel/metal hydride batteries

Ultrasonic method was used to recycle nickel/metal hydride (MH-Ni) batteries under undestroyed state. The effects of ultrasonic on electrode material performance of MH-Ni batteries were investigated by using SEM, EDAX and XRD. The results indicate that with the ultrasonic time increasing, there are obvious dispersing phenomena in the positive and negative electrodes. This can make the inertia oxidation layer break off from the negative electrode, and the fresh surface comes out. These changes can increase the reaction centers of the active materials, as well as improve the catalysis capability and discharge ability. But if the ultrasonic time is too long, it can make the active materials reunite and accelerate its pulverization, and lead to its degradation. The improvement of electrochemical performance for MH-Ni batteries is obvious by ultrasonic for 6 h continuously.