NEGATIVE ELECTRODE FOR ELECTROCHEMICAL ELEMENT AND A LITHIUM ION SECONDARY BATTERY

The inventive negative electrode for the electrochemical element includes a negative electrode composition layer provided on at least one surface of a current collector made of a metal foil; in which the negative electrode composition layer includes material S comprising Si and a hardly-graphitizable carbon material as a negative electrode active material; in which assuming that the whole amount of the negative electrode active material contained in the negative electrode composition layer is 100 mass %, a ratio of the material S is 50 to 90 mass % and a ratio of the hardly-graphitizable carbon materials is 10 to 50 mass %. The inventive lithium ion secondary battery includes a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte liquid, and the negative electrode is constituted by the negative electrode for the electrochemical element of the present invention.