Method of preparing a composite electrode for non-aqueous, high-energy batteries comprising: a. a step of pouring, on a composite electrode, a medium comprising: - at least one ionic liquid and possibly - at least one solvent, or - at least one polymer, or - a mixture of at least one solvent and one polymer said medium likewise comprising at least one lithium or sodium salt having i. either at least one inorganic molecular precursor comprising at least one hydrolysable group of the general formula: R' x 4-x Si in which: - x is a whole number varying from 0 to 4, - R represents an alkyl group with 1 to 4 carbon atoms, and - R' represents: * an alkyl group comprising from 1 to 4 carbon atoms, or * an aryl group comprising from 6 to 30 carbon atoms, or * a halogen atom in the absence of an acid and possibly in the presence of a catalyst which is able to reduce the polycondensation time, chosen from metals, metallic complexes, metallic oxides and metallic salts, ii. or at least one polymerisable monomer, iii. or a mixture of both, said medium being in excess so as to impregnate the porosity of the electrode and to form a film on the surface of said electrode, b. a polycondensation step in situ of the at least one inorganic molecular precursor or a polymerisation step of the at least one polymerisable monomer or of the mixture thereof by leaving to rest for a duration which can stretch to several days until a gel is obtained, containing within it the ionic liquid and the aforementioned lithium or sodium salt and possibly the solvent or the polymer or the mixture of both, said gel being situated both within the porosity of said composite electrode and in the form of a layer in contact with said composite electrode, in order to obtain a continuous network between the electrolyte contained within the electrode and the ionogel electrolyte situated in contact with the electrode, and possibly c. a step of eliminating the water until the water content of the ionic conductive gel is less than 50 ppm. a. a step of pouring, on a composite electrode, a medium comprising: - at least one ionic liquid and possibly - at least one solvent, or - at least one polymer, or - a mixture of at least one solvent and one polymer said medium likewise comprising at least one lithium or sodium salt having i. either at least one inorganic molecular precursor comprising at least one hydrolysable group of the general formula: R' x 4-x Si in which: - x is a whole number varying from 0 to 4, - R represents an alkyl group with 1 to 4 carbon atoms, and - R' represents: * an alkyl group comprising from 1 to 4 carbon atoms, or * an aryl group comprising from 6 to 30 carbon atoms, or * a halogen atom in the absence of an acid and possibly in the presence of a catalyst which is able to reduce the polycondensation time, chosen from metals, metallic complexes, metallic oxides and metallic salts, ii. or at least one polymerisable monomer, iii. or a mixture of both, said medium being in excess so as to impregnate the porosity of the electrode and to form a film on the surface of said electrode, - at least one ionic liquid and possibly - at least one solvent, or - at least one polymer, or - a mixture of at least one solvent and one polymer i. either at least one inorganic molecular precursor comprising at least one hydrolysable group of the general formula: R' x 4-x Si - x is a whole number varying from 0 to 4, - R represents an alkyl group with 1 to 4 carbon atoms, and - R' represents: * an alkyl group comprising from 1 to 4 carbon atoms, or * an aryl group comprising from 6 to 30 carbon atoms, or * a halogen atom * an alkyl group comprising from 1 to 4 carbon atoms, or * an aryl group comprising from 6 to 30 carbon atoms, or * a halogen atom ii. or at least one polymerisable monomer, iii. or a mixture of both, b. a polycondensation step in situ of the at least one inorganic molecular precursor or a polymerisation step of the at least one polymerisable monomer or of the mixture thereof by leaving to rest for a duration which can stretch to several days until a gel is obtained, containing within it the ionic liquid and the aforementioned lithium or sodium salt and possibly the solvent or the polymer or the mixture of both, said gel being situated both within the porosity of said composite electrode and in the form of a layer in contact with said composite electrode, in order to obtain a continuous network between the electrolyte contained within the electrode and the ionogel electrolyte situated in contact with the electrode, and possibly c. a step of eliminating the water until the water content of the ionic conductive gel is less than 50 ppm.