A power disconnection apparatus includes a soft-shell Li ion battery and a power disconnection device. The soft-shell Li ion battery includes anode pin and a cathode pin and a soft shell enclosing the soft-shell Li ion battery. The power disconnection device includes a panel attaching to the surface of the shell of the soft-shell Li ion battery and a separation unit arranged at topside of the panel and corresponding to one of the anode pin and the cathode pin. The shell has expansion when the soft-shell Li ion battery is over-charged and the panel is move away from the soft-shell Li ion battery. Therefore, the separation unit disconnects power to the anode pin or the cathode pin.