Patent ID: 8435671

Claim:
An electrode made of a multilayer material, the multilayer material comprising: a solid support; and at least two superposed solid layers which both contain particles of an electrochemically active material and a binder, the first solid layer adhering to the solid support and the second solid layer adhering directly to the first solid layer; and wherein: the multilayer material has at least one of the following three properties: (1) the first solid layer has a thickness, measured using a scanning electron microscope method, constant to at least 95%, (2) the second solid layer has a thickness, measured using a scanning electron microscope method, constant to at least 95%, and (3) an average depth of penetration of the second solid layer into the first solid layer is less than 10% of the thickness of the first solid layer; and wherein the binder present in the first solid layer is of a different nature from the binder present in the second solid layer, and wherein, at 25° C: the binder present in the first layer is a natural rubber or an artificial rubber that is soluble in water with a concentration of greater than 1 g/liter and the binder present in the second solid layer is of a PVDF or PTFE type and is soluble in water with a concentration of less than 1 g/liter; and the PVDF or PTFE type binder present in the second layer is soluble in a solvent different from water with a concentration of greater than 1 g/liter, and the natural rubber or an artificial rubber binder present in the first solid layer is soluble in the said solvent different from water with a concentration of less than 1 g/liter wherein the electrochemically active material of one of the layers is selected from the group consisting of LiFePO 4 , carbon-coated LiFePO 4 , FePO 4 , carbon-coated FePO 4 , and mixtures thereof; and the electrochemically active material of the other layer is selected from the group consisting of LiCoO 2 , LiMn 2 O 4 , LiMn 1/3 Co 1/3 Ni 1/3 O 2 , LiNi x Co y Al z O 2 (0<x, y, z<1), and mixtures thereof.