Battery pack has protective coating formed over unit cell by immersing unit cell into polyurethane emulsion solution

摘要

A unit cell (2) is immersed into polyurethane emulsion solution containing reaction product obtained from polyol mixture having functional group greater than 2.05 and active hydrogen group, to form protective coating over the cell. The polyol mixture includes bi-functional polyol group and polyol more than tri-functional group. The polyurethane emulsion solution includes carbon irradiated with laser. The polyurethane emulsion is applied from peripheral surface of unit cell to peripheral surface of holder (4) fixed to edge of the cell. An Independent claim is also included for battery pack manufacturing method.