As shown in Fig. 2(c), the anode current collector (anode C.C.) was placed in an inclined manner such that the angle between the anode C.C. and the cathode current collector (cathode C.C.) was about 3°. The advantage of the taper-end structure is that it maintains the natural downward movement of particles, allows only the particles smaller than the clearance of the bottom end between the anode C.C. and the cathode C.C. to flow out, and prevents the cell from being clogged by zinc particles.