{
  "$type": "site.standard.document",
  "description": "To provide an electrolytic copper foil for a negative electrode for a lithium-ion secondary battery with which it is possible to produce a long-life lithium-ion secondary battery in which there is no decline in the capacity retention ratio even when the charge-discharge cycling is repeated, that…",
  "path": "/patents/982931",
  "publishedAt": "2013-10-23T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "C22F1/08",
    "FURUKAWA ELECTRIC CO LTD [JP]"
  ],
  "textContent": "To provide an electrolytic copper foil for a negative electrode for a lithium-ion secondary battery with which it is possible to produce a long-life lithium-ion secondary battery in which there is no decline in the capacity retention ratio even when the charge-discharge cycling is repeated, that has long life, and no deformation of a negative electrode current collector occurs. The electrolytic copper foil constituting the negative electrode current collector for the lithium-ion secondary battery has, after heat treatment at from 200 to 400°C, a 0.2% proof stress of 250N/mm 2 or more, and elongation of 2.5% or more; and the surface on which an active material layer of the electrolytic copper foil is provided has been rust-proofed, or roughened and rust-proofed. As a result of analysis of the depth profile (depth direction) obtained by performing secondary ion mass spectrometry (SIMS) in the thickness direction of the copper foil, the copper foil including: chlorine (Cl), carbon (C), and oxygen (O) each in a concentration of 10 17 to 5×10 20 atoms/cm 3 , and sulfur (S) and nitrogen (N) each in a concentration of 10 15 to 10 19 atoms/cm 3 .",
  "title": "LITHIUM-ION SECONDARY BATTERY, ELECTRODE FOR SECONDARY BATTERY, AND ELECTROLYTIC COPPER FOIL FOR SECONDARY BATTERY ELECTRODE"
}