Lithium batteries have found a wide range of applications due to their very compact energy packing and effective cost. Theoretically Li-cells can hold up to 5V, however to date no mass-produced rechargeable battery surpassed 4 V. The structure here analyzed consists of: lithium porous cathode, solid electrolyte and silver anode. A spinel LiNi 0.4 X 0.1 Mn 1.5 O 4 sol-gel layer was deposited on a porous substrate in order to obtain a higher specific surface for a single chip. The anode was thermally evaporated Ag. The electrolyte used was a sol-gel hybrid layer containing Li ions. The devices fabricated on ceramic wafers, displayed high capacities