NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

A non-aqueous electrolyte secondary battery using lithium-containing transition metal composite oxide which has a layer structure, contains a lot of Ni and Mn and is inexpensive as a positive electrode active material and attaining high output characteristics even under low temperature environment is provided. The non-aqueous electrolyte secondary battery includes a positive electrode 11 containing a positive electrode active material, a negative electrode 12 containing a negative electrode active material and a non-aqueous electrolyte 14 having lithium ion conductivity, wherein lithium-containing transition metal composite oxide having a layer structure and being represented by a general formula Li 1+x Ni a Mn b Co c O 2+d wherein x, a, b, c and d satisfy x+a+b+c=1, 0.25¤ a ¤0.60, 0.25¤ b ¤ 0.60, 0¤ c ¤ 0.40, 0¤ x ¤ 0.10, 0.7¤ a/b ¤ 2.0 and -0.1¤ d ¤ 0.1 is used as the positive electrode active material of positive electrode, and the surface of positive electrode active material is covered with an amorphous carbon material and a conductive agent of amorphous carbon material is inserted between particles of the positive electrode active material.