Nonaqueous electrolyte secondary battery and manufacturing method thereof

摘要

The present invention provides a method of manufacturing a nonaqueous electrolyte secondary battery in which graphite fissuring during rolling of the negative electrode mixture layer is prevented and a deterioration in the performance of the battery is thereby suppressed. The manufacturing method provided by the present invention is a method of manufacturing a nonaqueous electrolyte secondary battery that has a positive electrode and a negative electrode, and includes: a coating step of coating a current collector 22 with a positive electrode mixture 23 containing graphite 25; a magnetic field application step of applying, to the negative electrode mixture 23 made to coat the current collector 22 in the coating step, a magnetic field in which the magnetic lines of force are oriented in one direction parallel to the plane of the current collector 22 coated with the negative electrode mixture 23; a drying step of drying the negative electrode mixture 23 to which the magnetic field has been applied in the magnetic field application step; and a rolling step of rolling a negative electrode mixture layer resulted from the drying step.

主权项

1. A method of manufacturing a nonaqueous electrolyte secondary battery that has a positive electrode and a negative electrode, the method comprising:
a coating step of coating a current collector with a graphite-containing negative electrode mixture; a magnetic field application step of applying, to the negative electrode mixture made to coat the current collector in the coating step, a magnetic field in which magnetic lines of force are oriented in one direction parallel to a wide side plane of the current collector coated with the negative electrode mixture; a drying step of drying the negative electrode mixture to which the magnetic field has been applied in the magnetic field application step; and a rolling step of rolling a negative electrode mixture layer resulted from the drying step, wherein the current collector is an elongated current collector and, in the magnetic field application step, a magnetic field is applied in which the magnetic lines of force are oriented in a width direction of the elongated current collector, wherein the width direction is defined as the direction that is orthogonal to the length direction of the elongated current collector and that runs from one long edge of the current collector to the other long edge.