METHOD FOR INSPECTING STATE OF WELDS IN BATTERY

The present invention provides a method for inspecting the state of welds in a battery, the state of welds being inspected for a battery having: a tap or current collection plate welded to a current collector of an electrode assembly in which the current collector and separation film have been wound or stacked; and a can housing or electrode lead welded to the tap or current collector plate. The method comprises: a first impedance measurement step for measuring first impedance by applying, prior to injecting electrolyte into a battery, alternating current or alternating voltage at a set frequency band; a first Cole-Cole plot preparation step for preparing a first Cole-Cole plot on the basis of the first impedance; and a primary state of welds determination step for determining the state of welds of the battery on the basis of x fractional value on the first Cole-Cole plot.