injector in which a slot portion was formed as shown in fig3 was used and two opening portions having an approximately rectangular section of 270 mm width were provided at an interval of 20 mm coating was performed for 1 hour under the conditions that the distance between the slot outlet and the support was 0 5 mm the slot clearance was 0 7 mm the width of the inlet side and outlet side lip surfaces was 3 mm and the carriage speed of the support was 1 m min the solid content of the electrode material coating compound was 60 by weight and the pressure of the liquid reservoir portion was 0 9 kg cm 2 the applied substance was formed compressively by means of a roller press after hot air drying so as to produce a positive pole sheet having a thickness of 370 u03bcm slurry was prepared through a process in which licovo 4 obtained by burning lithium carbonate cobalt oxide and vanadium pentoxide in the air at 1 000 u00b0 c for 24 hours as negative pole active material and acetylene black and graphite as conductive agent were mixed in the proportion of 86 3 and 6 parts by weight respectively styrene butadiene rubber and carboxymethyl cellulose as bonding agent were added thereto by 4 and 1 parts by weight respectively water was added thereto and then the whole was kneaded the slurry was applied onto the opposite surfaces of copper foil having thickness of 20 u03bcm successively one surface after the other in the method of the present invention by use of such a coating apparatus as shown.