| 摘要 |
PROBLEM TO BE SOLVED: To suppress the swelling of a binder in high temperature use of high temperature storage in the state such that while a positive electrode is charged, the electrical peeling of a conductive thin layer such as an anchor layer caused by the swelling of the binder, and high heat generation in overcharge. SOLUTION: A nonaqueous electrolyte secondary battery has a positive electrode 2 comprising a positive current collector 9, a positive active material layer 11, and a conductive thin layer 10 such as an anchor layer arranged between them, a negative electrode arranged via a positive electrode and a separator, and a nonaqueous electrolyte, the conductive thin layer of the positive electrode consists of a carbon based conductive agent and a binder selected, so that the rate of increase for the impedance in the overcharging state to the normal charging state is 300% or more and the ral increase rate of impedance after high temperature use or high temperature storage exceeding 85 deg.C to the normal charging state is 210% or less. As the binder constituting the conductive thin layer, for example, a mixture of a rubber base binder and a fluororesin base binder is used. |
