The invention relates to a preparation method for a 
graphene like cobaltosic 
oxide nano 
film material and an application of an 
electrode slice. A 
cobalt salt and a 
sodium salt are respectively weighed and are dissolved in deionized water, and then a 
cobalt salt solution and a 
sodium salt solution are obtained; equal volume of the 
cobalt salt solution and the 
sodium salt solution are taken to be mixed, perform thermostatic water bath and be stirred uniformly, and then a 
mixed solution is obtained; 
ammonium water is added to the 
mixed solution, and then a cobalt 
ammonia coordination compound solution containing the 
sodium salt is obtained; 
hydrogen peroxide is dipped into the cobalt 
ammonia coordination compound solution then, hydro-
thermal treatment is performed on the obtained 
mixed solution under sealing, and a black precipitate is obtained; and the black precipitate is washed successively via the deionized water and absolute ethyl 
alcohol and is dried under 
air atmosphere, and a 
graphene like cobaltosic 
oxide nano film is obtained. The 
graphene like cobaltosic 
oxide nano film is mixed with a conductive agent and a binder, and a 
slurry is obtained after stirring; and the 
slurry is uniformly coated on foam 
nickel after pretreatment in a scraping manner, and the 
electrode slice is obtained through 
drying and tablet compressing. An equipment condition needed by the preparation method is simpler, operation is convenient, preparation cost is low, and the preparation method is suitable for factory large-scale production.