▎ 摘　　要

NOVELTY - The method comprises (i) ultrasonically dispersing graphene oxide (GO) aqueous solution, placing in ice water bath for magnetic stirring, dropping iron chloride solution according to a certain mol ratio, finishing dripping, centrifuging and separating the obtained solution, washing the obtained precipitate with deionized water, vacuum freezing and drying, (ii) calcining the frozen and dried graphene oxide/iron ion precursor under the protection of inert gas, then using diluted hydrogen chloride solution to wash, using deionizing water to wash to neutral, centrifugally separating, vacuum freeze-drying and drying to obtain nano-porous graphene, and (iii) dispersing the nanofibril graphene in the mixed solution of ethanol and water, filtering to obtain a filter cake, drying the filter cake and rolling to obtain the flexible porous graphene electrode sheet. USE - Method for controllably preparing nano porous graphene flexible electrode based on ion adsorption, which is directly used as negative pole piece of the rechargeable battery (claimed) and lithium ion battery. ADVANTAGE - The method: is simple, and suitable for preparing nano porous graphene in large scale; reduces the diffusion distance of the ion migration in the rechargeable battery charging/discharging process; and improves the electrode dynamics and quality transmission problem, and improves the conductivity of the electrode. The graphene has uniform and controllable pore size, excellent charging-discharging specific capacity and good cycle stability.