Patent ID: 8216719

Claim:
A non-aqueous secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolyte, the positive electrode comprising a positive electrode material mixture layer containing a lithium-containing transition metal oxide, the negative electrode comprising a negative electrode material mixture layer and a porous layer formed on the negative electrode material mixture layer, the negative electrode material mixture layer including a negative electrode material comprising a core and a carbon covering layer covering a surface of the core, the core being formed of a material comprising silicon and oxygen, an atomic ratio x of the oxygen to the silicon of the core being 0.5≦x≦1.5, the porous layer containing an insulating material unreactive with lithium, wherein the material comprising silicon and oxygen has a peak at least in a range of 1850 to 1860 eV in an X-ray absorption near edge structure spectrum at the K absorption edge of Si in a state in which discharge of the battery is finished.