▎ 摘　　要

NOVELTY - The present invention provides a method for preparing a composite electrode, which comprises the following steps: step (a): providing a conductive substrate and immersing the conductive substrate in a first solution and then taking it out, and then washing with deionized water, wherein the first The solution contains graphene and carbon nanotubes; step (b): subsequently immersed in a second solution and then taken out, and then washed with deionized water, wherein the second solution contains divalent manganese ions; step (c): Then it is immersed in a third solution and then taken out, and then washed with deionized water to obtain a treated conductive substrate, wherein the third solution contains permanganate ions; and step (d): heating the treated conductive substrate The conductive substrate to obtain the composite electrode. The composite electrode preparation method of the present invention has the advantages of simple manufacturing process, low manufacturing cost and low energy consumption.