Abstract: Herein presented is a high electrical conductivity, uniform, material based on nanoparticles-Li+-polycarboxylate grafted few-layer graphene oxide including perovskite type nanoparticles for filler in polymeric matrices, in direct and reverse osmosis membranes, in lithium batteries, among others. The material is obtained by a method comprising the step of: preparation of a composite material having polymers with mono- or di-acid groups covalently bonded to graphene; optionally further comprising the preparation of a composite material with graphene covalently bonded to polymers having mono- or di-acid groups that have been replaced by lithium ion; and optionally further comprising the preparation of a composite material with graphene covalently bonded to polymers having mono- or di-acid groups that have been replaced by lithium ion in addition to grafted nanoparticles, including nanoparticles perovskite type.